C++ Win32 为按钮显示具有透明背景的位图
C++ Win32 Displaying a bitmap with transparent background for button
我有一个子类按钮,我希望它显示具有透明背景的位图。在互联网上搜索后,我发现你必须使用 AlphaBlend 函数(我试过了,但也没有用)。我也看到了这个 线程,我尝试了这些步骤,但我做不到。只要我可以获得带有透明背景图像的按钮,我就可以使用 GDI 或 GDI+。
示例:
这是我的代码——我知道它很乱,但请接受它,因为我尝试了很多东西来尝试让它工作(有很多复制和粘贴)
更新:这里又是代码,但没有多余的内容,是的,我确实在 windows.
上尝试了 WS_EX_LAYERED
// CustomButton2.cpp : Defines the entry point for the application.
//
#include "framework.h"
#include "CustomButton2.h"
#include <commctrl.h>
#include <gdiplus.h>
#include <system_error>
#include "SkinClass/skin.h"
#define MAX_LOADSTRING 100
#define CRAPPY 567
#pragma comment(linker,"/manifestdependency:\"type='win32' name='Microsoft.Windows.Common-Controls' " "version='6.0.0.0' processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"")
// Global Variables:
HINSTANCE hInst; // current instance
WCHAR szTitle[MAX_LOADSTRING]; // The title bar text
WCHAR szWindowClass[MAX_LOADSTRING]; // the main window class name
const char g_szClassName[] = "MyClassName";
// Forward declarations of functions included in this code module:
ATOM MyRegisterClass(HINSTANCE hInstance);
void RegisterClass1(HINSTANCE);
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
/// Turn given window into a layered window and load a bitmap from given resource ID
/// into it.
/// The window will be resized to fit the bitmap.
/// Bitmap must be 32bpp, top-down row order, premultiplied alpha.
///
/// \note For child windows, this requires Win 8 or newer OS
/// (and "supportedOS" element for Win 8 in application manifest)
///
/// \exception Throws std::system_error in case of any error.
void SetLayeredWindowFromBitmapResource(
HWND hwnd, UINT bitmapResourceId, HINSTANCE hInstance = nullptr)
{
// Enable "layered" mode for the child window. This enables full alpha channel
// transparency.
// GetWindowLong() won't reset the last error in case of success.
// As we can't judge from the return value of GetWindowLong() alone if
// the function was successful (0 may be returned even in case of
// success), we must reset the last error to reliably detect errors.
::SetLastError(0);
DWORD exStyle = ::GetWindowLong(hwnd, GWL_EXSTYLE);
if (!exStyle)
{
// NOTE: Call GetLastError() IMMEDIATELY when a function's return value
// indicates failure and it is documented that said function supports
// GetLastError().
// ANY other code (be it your own or library code) before the next line
// must be avoided as it may invalidate the last error value.
if (DWORD err = ::GetLastError())
throw std::system_error(static_cast<int>(err),
std::system_category(),
"SetLayeredWindowFromBitmapResource: Could not get extended window style");
}
// SetWindowLong() won't reset the last error in case of success.
// As we can't judge from the return value of GetWindowLong() alone if
// the function was successful (0 may be returned even in case of
// success), we must reset the last error to reliably detect errors.
::SetLastError(0);
if (!::SetWindowLong(hwnd, GWL_EXSTYLE, exStyle | WS_EX_LAYERED))
{
if (DWORD err = ::GetLastError())
throw std::system_error(static_cast<int>(err),
std::system_category(),
"SetLayeredWindowFromBitmapResource: Could not set extended window style");
}
// Use RAII ( https://en.wikipedia.org/wiki/Resource_acquisition_is_initialization )
// to cleanup resources even in case of exceptions.
// This greatly simplifies the code because now we don't have to manually cleanup the
// resources at every location in the code where we throw an exception.
struct Resources {
HBITMAP hImage = nullptr;
HGDIOBJ hOldImage = nullptr;
HDC hMemDC = nullptr;
// This destructor will be automatically called before the function
// SetLayeredWindowFromBitmapResource() returns aswell as any locations
// in the code where the "throw" keyword is used to throw an exception.
~Resources()
{
if (hMemDC)
{
if (hOldImage)
::SelectObject(hMemDC, hOldImage);
::DeleteDC(hMemDC);
}
if (hImage)
::DeleteObject(hImage);
}
} res;
// Make it possible to use nullptr as an argument for the hInstance parameter of
// this function. This means we will load the resources from the current executable
// (instead of another DLL).
if (!hInstance)
hInstance = ::GetModuleHandle(nullptr);
// Load bitmap with alpha channel from resource.
// Flag LR_CREATEDIBSECTION is required to create a device-independent bitmap that
// preserves the alpha channel.
res.hImage = reinterpret_cast<HBITMAP>(::LoadImage(
hInstance, MAKEINTRESOURCE(bitmapResourceId), IMAGE_BITMAP,
0, 0, LR_CREATEDIBSECTION));
if (!res.hImage)
{
DWORD err = ::GetLastError();
throw std::system_error(static_cast<int>(err),
std::system_category(),
"SetLayeredWindowFromBitmapResource: Could not load bitmap resource");
}
// Get bitmap information (width, height, etc.)
BITMAP imgInfo{ 0 };
if (!::GetObject(res.hImage, sizeof(imgInfo), &imgInfo))
{
DWORD err = ::GetLastError();
throw std::system_error(static_cast<int>(err),
std::system_category(),
"SetLayeredWindowFromBitmapResource: Could not get bitmap information");
}
if (imgInfo.bmBitsPixel != 32 || imgInfo.bmPlanes != 1)
{
// Use a constant error value here because this is our own error condition.
// Of course GetLastError() wouldn't return anything useful in this case.
DWORD err = ERROR_INVALID_DATA;
throw std::system_error(err, std::system_category(),
"SetLayeredWindowFromBitmapResource: bitmap must be 32 bpp, single plane");
}
// Create a memory DC that will be associated with the image.
// UpdateLayeredWindow() can't use image directly, it must be in a memory DC.
res.hMemDC = ::CreateCompatibleDC(nullptr);
if (!res.hMemDC)
{
DWORD err = ::GetLastError();
throw std::system_error(static_cast<int>(err),
std::system_category(),
"SetLayeredWindowFromBitmapResource: Could not create memory DC");
}
res.hOldImage = ::SelectObject(res.hMemDC, res.hImage);
if (!res.hOldImage)
{
DWORD err = ::GetLastError();
throw std::system_error(static_cast<int>(err),
std::system_category(),
"SetLayeredWindowFromBitmapResource: Could not select bitmap into memory DC");
}
// Assign the image to the child window, making it transparent.
SIZE size{ imgInfo.bmWidth, imgInfo.bmHeight };
POINT ptSrc{ 0, 0 };
BLENDFUNCTION blend{ AC_SRC_OVER, 0, 255, AC_SRC_ALPHA };
if (!::UpdateLayeredWindow(hwnd, nullptr, nullptr, &size, res.hMemDC, &ptSrc,
0, &blend, ULW_ALPHA))
{
DWORD err = ::GetLastError();
throw std::system_error(static_cast<int>(err),
std::system_category(),
"SetLayeredWindowFromBitmapResource: Could not update layered window");
}
// Destructor of res object will cleanup resources here!
}
int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
_In_opt_ HINSTANCE hPrevInstance,
_In_ LPWSTR lpCmdLine,
_In_ int nCmdShow)
{
UNREFERENCED_PARAMETER(hPrevInstance);
UNREFERENCED_PARAMETER(lpCmdLine);
// TODO: Place code here.
RegisterClass1(hInstance);
HWND hWnd = CreateWindowExA(WS_EX_LAYERED, g_szClassName, "Scenes", WS_OVERLAPPEDWINDOW | WS_EX_LAYERED, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL,
hInstance, NULL);
HWND hButton = CreateWindow(TEXT("BUTTON"), TEXT("START EDITING!"), WS_CHILD | WS_VISIBLE | BS_OWNERDRAW | WS_EX_LAYERED, 1, 1,228, 228,
hWnd, (HMENU)CRAPPY, NULL, NULL);
//SetLayeredWindowFromBitmapResource(hButton, ID_THECIRCLE, hInstance);
SetLayeredWindowAttributes(hWnd, 0, 249, LWA_ALPHA);
ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);
SetLayeredWindowFromBitmapResource(hButton, ID_THECIRCLE);
MSG msg;
// Main message loop:
while (GetMessage(&msg, nullptr, 0, 0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return (int) msg.wParam;
}
//
// FUNCTION: RegisterClass1()
//
// PURPOSE: Registers the class
//
// COMMENTS:
//
//
//
//
void RegisterClass1(HINSTANCE hInstance) {
WNDCLASSEXA wc;
wc.cbSize = sizeof(WNDCLASSEX);
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
//wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
wc.hbrBackground = CreateSolidBrush(RGB(255, 0, 0));
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
wc.hInstance = hInstance;
wc.lpfnWndProc = WndProc;
wc.lpszClassName = g_szClassName;
wc.lpszMenuName = "MENU";
wc.style = CS_HREDRAW | CS_VREDRAW;
if (!RegisterClassEx(&wc))
{
MessageBox(NULL, "Window Registration Failed!", "Error!",
MB_ICONEXCLAMATION | MB_OK);
}
}
//
// FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)
//
// PURPOSE: Processes messages for the main window.
//
// WM_COMMAND - process the application menu
// WM_PAINT - Paint the main window
// WM_DESTROY - post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message)
{
case WM_COMMAND:
{
int wmId = LOWORD(wParam);
// Parse the menu selections:
switch (wmId)
{
case IDM_ABOUT:
break;
case IDM_EXIT:
DestroyWindow(hWnd);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
}
break;
case WM_PAINT:
{
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hWnd, &ps);
// TODO: Add any drawing code that uses hdc here...
EndPaint(hWnd, &ps);
}
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}
从Window8开始,WS_EX_LAYERED
可用于子控件。
方法:清单文件需要指定至少 Window 8 兼容性(仅从 Window 8 开始支持子分层)。
参考:Targeting your application for Windows
代码示例:(已删除错误检查)
// Test_CustomButton.cpp : Defines the entry point for the application.
//
#include "framework.h"
#include "Test_CustomButton.h"
#include <commctrl.h>
#include <system_error>
#pragma comment (lib,"Comctl32.lib")
#define MAX_LOADSTRING 100
#define IDC_OWNERDRAWBUTTON 101
#define CRAPPY 567
// Global Variables:
HINSTANCE hInst; // current instance
WCHAR szTitle[MAX_LOADSTRING]; // The title bar text
WCHAR szWindowClass[MAX_LOADSTRING]; // the main window class name
// Forward declarations of functions included in this code module:
ATOM MyRegisterClass(HINSTANCE hInstance);
BOOL InitInstance(HINSTANCE, int);
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
INT_PTR CALLBACK About(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK OwnerDrawButtonProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData);
void SetLayeredWindowFromBitmapResource(
HWND hwnd, UINT bitmapResourceId, HINSTANCE hInstance = nullptr)
{
DWORD exStyle = ::GetWindowLong(hwnd, GWL_EXSTYLE);
SetWindowLong(hwnd, GWL_EXSTYLE, exStyle | WS_EX_LAYERED);
struct Resources {
HBITMAP hImage = nullptr;
HGDIOBJ hOldImage = nullptr;
HDC hMemDC = nullptr;
~Resources()
{
if (hMemDC)
{
if (hOldImage)
::SelectObject(hMemDC, hOldImage);
::DeleteDC(hMemDC);
}
if (hImage)
::DeleteObject(hImage);
}
} res;
if (!hInstance)
hInstance = ::GetModuleHandle(nullptr);
res.hImage = reinterpret_cast<HBITMAP>(::LoadImage(
hInstance, MAKEINTRESOURCE(bitmapResourceId), IMAGE_BITMAP,
0, 0, LR_CREATEDIBSECTION));
BITMAP imgInfo{ 0 };
GetObject(res.hImage, sizeof(imgInfo), &imgInfo);
res.hMemDC = ::CreateCompatibleDC(nullptr);
res.hOldImage = ::SelectObject(res.hMemDC, res.hImage);
// Assign the image to the child window, making it transparent.
SIZE size{ imgInfo.bmWidth, imgInfo.bmHeight };
POINT ptSrc{ 0, 0 };
BLENDFUNCTION blend{ AC_SRC_OVER, 0, 200, AC_SRC_ALPHA };
UpdateLayeredWindow(hwnd, nullptr, nullptr, &size, res.hMemDC, &ptSrc,
0, &blend, ULW_ALPHA);
// Destructor of res object will cleanup resources here!
}
int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
_In_opt_ HINSTANCE hPrevInstance,
_In_ LPWSTR lpCmdLine,
_In_ int nCmdShow)
{
UNREFERENCED_PARAMETER(hPrevInstance);
UNREFERENCED_PARAMETER(lpCmdLine);
LoadStringW(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
LoadStringW(hInstance, IDC_TESTCUSTOMBUTTON, szWindowClass, MAX_LOADSTRING);
MyRegisterClass(hInstance);
if (!InitInstance (hInstance, nCmdShow))
{
return FALSE;
}
HACCEL hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_TESTCUSTOMBUTTON));
MSG msg;
while (GetMessage(&msg, nullptr, 0, 0))
{
if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
return (int) msg.wParam;
}
ATOM MyRegisterClass(HINSTANCE hInstance)
{
WNDCLASSEXW wcex;
wcex.cbSize = sizeof(WNDCLASSEX);
wcex.style = CS_HREDRAW | CS_VREDRAW;
wcex.lpfnWndProc = WndProc;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = 0;
wcex.hInstance = hInstance;
wcex.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_TESTCUSTOMBUTTON));
wcex.hCursor = LoadCursor(nullptr, IDC_ARROW);
wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wcex.lpszMenuName = MAKEINTRESOURCEW(IDC_TESTCUSTOMBUTTON);
wcex.lpszClassName = szWindowClass;
wcex.hIconSm = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));
return RegisterClassExW(&wcex);
}
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
hInst = hInstance; // Store instance handle in our global variable
HWND hWnd = CreateWindowW(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, nullptr, nullptr, hInstance, nullptr);
ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);
if (!hWnd)
{
return FALSE;
}
ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);
return TRUE;
}
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message)
{
case WM_CREATE:
{
HWND hButton = CreateWindowEx(0, L"button", NULL, WS_CHILD | WS_VISIBLE | BS_OWNERDRAW, 150, 50, 80, 80, hWnd, (HMENU)IDC_OWNERDRAWBUTTON, hInst, NULL);
SetWindowSubclass(hButton, &OwnerDrawButtonProc, IDC_OWNERDRAWBUTTON, 0);
}
break;
case WM_COMMAND:
{
int wmId = LOWORD(wParam);
// Parse the menu selections:
switch (wmId)
{
case IDM_ABOUT:
DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
break;
case IDM_EXIT:
DestroyWindow(hWnd);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
}
break;
case WM_PAINT:
{
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hWnd, &ps);
// Used be test
HPEN hPen = CreatePen(PS_SOLID, 2, RGB(255, 0, 0));
SelectObject(hdc, hPen);
MoveToEx(hdc, 150, 150, NULL);
LineTo(hdc, 200, 60);
LineTo(hdc, 250, 150);
LineTo(hdc, 150, 150);
EndPaint(hWnd, &ps);
}
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}
// Message handler for about box.
INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
UNREFERENCED_PARAMETER(lParam);
switch (message)
{
case WM_INITDIALOG:
return (INT_PTR)TRUE;
case WM_COMMAND:
if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL)
{
EndDialog(hDlg, LOWORD(wParam));
return (INT_PTR)TRUE;
}
break;
}
return (INT_PTR)FALSE;
}
LRESULT CALLBACK OwnerDrawButtonProc(HWND hWnd, UINT uMsg, WPARAM wParam,
LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
switch (uMsg)
{
case WM_PAINT:
{
RECT rc;
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hWnd, &ps);
SetLayeredWindowFromBitmapResource(hWnd, IDB_BITMAP1);
EndPaint(hWnd, &ps);
return 0;
}
case WM_NCDESTROY:
RemoveWindowSubclass(hWnd, &OwnerDrawButtonProc, 1);
break;
}
return DefSubclassProc(hWnd, uMsg, wParam, lParam);
}
调试:
注:
我测试的时候发现需要满足以下条件:
要加载的图像必须是 32 bpp、自上而下的位图
预乘 alpha 通道。
这是我的 32 bpp image 测试。
开头说了,需要添加manifest文件,可以
自己创建一个 .manifest 文件。然后在编译器中添加。
只需要给子控件添加WS_EX_LAYERED
样式,
因为你的要求是让按钮透明。
在我的例子中,所提供的代码不起作用,因为它抛出异常并且我没有正确添加清单文件。我想注意一些事情:
用 gimp 制作的位图图像不工作;使用我在问题中链接的线程中建议的内容,即 PixelFormer。在 Pixel Former 中转到 "file",然后选择 "Import" 并选择您的文件(在我的例子中它是透明的圆圈 png)。接下来转到 "export" 并选择位图 bmp(它会说 windows 位图)。一旦你这样做了,已经 A8:R8:G8:B8 (32bpp) 将被选中,接下来你必须选中最后两个框 "Premultiplied Alpha" 和 "Top-down row order"。必须要说的是,图像确实有一个 alpha 通道,而且它是透明的。不要被愚弄,打开画图,你看到黑色背景,你认为透明度不存在——透明就在那里工作……如果你在 photoshop(我认为)或复杂的软件中打开它图像编辑程序,您将在图像中看到透明背景。
manifest.xml
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
<compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
<application>
<!-- Windows 10 -->
<supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}"/>
<!-- Windows 8.1 -->
<supportedOS Id="{1f676c76-80e1-4239-95bb-83d0f6d0da78}"/>
<!-- Windows 8 -->
<supportedOS Id="{4a2f28e3-53b9-4441-ba9c-d69d4a4a6e38}"/>
<!-- Windows 7 -->
<supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}"/>
<!-- Windows Vista -->
<supportedOS Id="{e2011457-1546-43c5-a5fe-008deee3d3f0}"/>
</application>
</compatibility>
<dependency>
<dependentAssembly>
<assemblyIdentity
type="win32"
name="Microsoft.Windows.Common-Controls"
version="6.0.0.0"
processorArchitecture="*"
publicKeyToken="6595b64144ccf1df"
language="*"
/>
</dependentAssembly>
</dependency>
</assembly>
复制上面的内容并保存为manifest.xml
我要注意的另一件事是添加一个清单条目文件:在我的例子中,我必须将它添加到 C:\Users\Rubel\source\repos\CustomButton2\CustomButton2 所以无论谁在将来查看这个,都将其替换为你的项目目录;例如,C:\Users\blah\source\repos\blah\blah(带有你的东西名称的废话)。将您的清单文件粘贴到那里(在目录中)。
然后您必须将其添加到 visual studio。您可以通过在解决方案资源管理器中右键单击您的项目(在我的例子中是 CustomButton2 )并转到 "Input and Output" 中的 "Manifest Tool" 来执行此操作。在这里输入 "Additional Manifest Files" 你的清单文件的路径(在我的例子中它是 manifest.xml 但如果你跟着,那么你的路径也应该是这种情况) 然后点击确定。
就是这样,如果您使用提供的代码 (Strive Sun - MSFT),它应该可以工作。
如果有人感兴趣,这是我的最终代码:
// CustomButton2.cpp : Defines the entry point for the application.
//
#include "framework.h"
#include "CustomButton2.h"
#include <commctrl.h>
#include <gdiplus.h>
#include <system_error>
#define MAX_LOADSTRING 100
#define CRAPPY 567
#define IDC_OWNERDRAWBUTTON 101
#pragma comment(linker,"/manifestdependency:\"type='win32' name='Microsoft.Windows.Common-Controls' " "version='6.0.0.0' processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"")
// Global Variables:
HINSTANCE hInst; // current instance
WCHAR szTitle[MAX_LOADSTRING]; // The title bar text
WCHAR szWindowClass[MAX_LOADSTRING]; // the main window class name
const char g_szClassName[] = "MyClassName";
// Forward declarations of functions included in this code module:
ATOM MyRegisterClass(HINSTANCE hInstance);
void RegisterClass1(HINSTANCE);
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK OwnerDrawButtonProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData);
void SetLayeredWindowFromBitmapResource(
HWND hwnd, UINT bitmapResourceId, HINSTANCE hInstance = nullptr)
{
DWORD exStyle = ::GetWindowLong(hwnd, GWL_EXSTYLE);
SetWindowLong(hwnd, GWL_EXSTYLE, exStyle | WS_EX_LAYERED);
struct Resources {
HBITMAP hImage = nullptr;
HGDIOBJ hOldImage = nullptr;
HDC hMemDC = nullptr;
~Resources()
{
if (hMemDC)
{
if (hOldImage)
::SelectObject(hMemDC, hOldImage);
::DeleteDC(hMemDC);
}
if (hImage)
::DeleteObject(hImage);
}
} res;
if (!hInstance)
hInstance = ::GetModuleHandle(nullptr);
res.hImage = reinterpret_cast<HBITMAP>(::LoadImage(
hInstance, MAKEINTRESOURCE(bitmapResourceId), IMAGE_BITMAP,
0, 0, LR_CREATEDIBSECTION));
BITMAP imgInfo{ 0 };
GetObject(res.hImage, sizeof(imgInfo), &imgInfo);
res.hMemDC = ::CreateCompatibleDC(nullptr);
res.hOldImage = ::SelectObject(res.hMemDC, res.hImage);
// Assign the image to the child window, making it transparent.
SIZE size{ imgInfo.bmWidth, imgInfo.bmHeight };
POINT ptSrc{ 0, 0 };
BLENDFUNCTION blend{ AC_SRC_OVER, 0, 200, AC_SRC_ALPHA };
UpdateLayeredWindow(hwnd, nullptr, nullptr, &size, res.hMemDC, &ptSrc,
0, &blend, ULW_ALPHA);
// Destructor of res object will cleanup resources here!
}
int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
_In_opt_ HINSTANCE hPrevInstance,
_In_ LPWSTR lpCmdLine,
_In_ int nCmdShow)
{
UNREFERENCED_PARAMETER(hPrevInstance);
UNREFERENCED_PARAMETER(lpCmdLine);
// TODO: Place code here.
RegisterClass1(hInstance);
HWND hWnd = CreateWindowExA(WS_EX_LAYERED, g_szClassName, "Scenes", WS_OVERLAPPEDWINDOW | WS_EX_LAYERED, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL,
hInstance, NULL);
HWND hButton = CreateWindow(TEXT("BUTTON"), TEXT("START EDITING!"), WS_CHILD | WS_VISIBLE | BS_OWNERDRAW | WS_EX_LAYERED, 1, 1,228, 228,
hWnd, (HMENU)CRAPPY, NULL, NULL);
SetWindowSubclass(hButton, &OwnerDrawButtonProc, IDC_OWNERDRAWBUTTON, 0);
//SetLayeredWindowFromBitmapResource(hButton, ID_THECIRCLE, hInstance);
SetLayeredWindowAttributes(hWnd, 0, 249, LWA_ALPHA);
ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);
//SetLayeredWindowFromBitmapResource(hButton, ID_THECIRCLE);
MSG msg;
// Main message loop:
while (GetMessage(&msg, nullptr, 0, 0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return (int) msg.wParam;
}
//
// FUNCTION: RegisterClass1()
//
// PURPOSE: Registers the class
//
// COMMENTS:
//
//
//
//
void RegisterClass1(HINSTANCE hInstance) {
WNDCLASSEXA wc;
wc.cbSize = sizeof(WNDCLASSEX);
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
//wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
wc.hbrBackground = CreateSolidBrush(RGB(255, 0, 0));
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
wc.hInstance = hInstance;
wc.lpfnWndProc = WndProc;
wc.lpszClassName = g_szClassName;
wc.lpszMenuName = "MENU";
wc.style = CS_HREDRAW | CS_VREDRAW;
if (!RegisterClassEx(&wc))
{
MessageBox(NULL, "Window Registration Failed!", "Error!",
MB_ICONEXCLAMATION | MB_OK);
}
}
//
// FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)
//
// PURPOSE: Processes messages for the main window.
//
// WM_COMMAND - process the application menu
// WM_PAINT - Paint the main window
// WM_DESTROY - post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message)
{
case WM_COMMAND:
{
int wmId = LOWORD(wParam);
// Parse the menu selections:
switch (wmId)
{
case IDM_ABOUT:
break;
case IDM_EXIT:
DestroyWindow(hWnd);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
}
break;
case WM_PAINT:
{
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hWnd, &ps);
// TODO: Add any drawing code that uses hdc here...
EndPaint(hWnd, &ps);
}
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}
LRESULT CALLBACK OwnerDrawButtonProc(HWND hWnd, UINT uMsg, WPARAM wParam,
LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
switch (uMsg)
{
case WM_PAINT:
{
RECT rc;
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hWnd, &ps);
SetLayeredWindowFromBitmapResource(hWnd, ID_THECIRCLE);
EndPaint(hWnd, &ps);
return 0;
}
case WM_NCDESTROY:
RemoveWindowSubclass(hWnd, &OwnerDrawButtonProc, 1);
break;
}
return DefSubclassProc(hWnd, uMsg, wParam, lParam);
}
申请运行:
我知道这很冗长,但我希望遇到此问题的任何人都能轻松理解,以便他们知道如何去做。
我有一个子类按钮,我希望它显示具有透明背景的位图。在互联网上搜索后,我发现你必须使用 AlphaBlend 函数(我试过了,但也没有用)。我也看到了这个
这是我的代码——我知道它很乱,但请接受它,因为我尝试了很多东西来尝试让它工作(有很多复制和粘贴)
更新:这里又是代码,但没有多余的内容,是的,我确实在 windows.
上尝试了 WS_EX_LAYERED// CustomButton2.cpp : Defines the entry point for the application.
//
#include "framework.h"
#include "CustomButton2.h"
#include <commctrl.h>
#include <gdiplus.h>
#include <system_error>
#include "SkinClass/skin.h"
#define MAX_LOADSTRING 100
#define CRAPPY 567
#pragma comment(linker,"/manifestdependency:\"type='win32' name='Microsoft.Windows.Common-Controls' " "version='6.0.0.0' processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"")
// Global Variables:
HINSTANCE hInst; // current instance
WCHAR szTitle[MAX_LOADSTRING]; // The title bar text
WCHAR szWindowClass[MAX_LOADSTRING]; // the main window class name
const char g_szClassName[] = "MyClassName";
// Forward declarations of functions included in this code module:
ATOM MyRegisterClass(HINSTANCE hInstance);
void RegisterClass1(HINSTANCE);
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
/// Turn given window into a layered window and load a bitmap from given resource ID
/// into it.
/// The window will be resized to fit the bitmap.
/// Bitmap must be 32bpp, top-down row order, premultiplied alpha.
///
/// \note For child windows, this requires Win 8 or newer OS
/// (and "supportedOS" element for Win 8 in application manifest)
///
/// \exception Throws std::system_error in case of any error.
void SetLayeredWindowFromBitmapResource(
HWND hwnd, UINT bitmapResourceId, HINSTANCE hInstance = nullptr)
{
// Enable "layered" mode for the child window. This enables full alpha channel
// transparency.
// GetWindowLong() won't reset the last error in case of success.
// As we can't judge from the return value of GetWindowLong() alone if
// the function was successful (0 may be returned even in case of
// success), we must reset the last error to reliably detect errors.
::SetLastError(0);
DWORD exStyle = ::GetWindowLong(hwnd, GWL_EXSTYLE);
if (!exStyle)
{
// NOTE: Call GetLastError() IMMEDIATELY when a function's return value
// indicates failure and it is documented that said function supports
// GetLastError().
// ANY other code (be it your own or library code) before the next line
// must be avoided as it may invalidate the last error value.
if (DWORD err = ::GetLastError())
throw std::system_error(static_cast<int>(err),
std::system_category(),
"SetLayeredWindowFromBitmapResource: Could not get extended window style");
}
// SetWindowLong() won't reset the last error in case of success.
// As we can't judge from the return value of GetWindowLong() alone if
// the function was successful (0 may be returned even in case of
// success), we must reset the last error to reliably detect errors.
::SetLastError(0);
if (!::SetWindowLong(hwnd, GWL_EXSTYLE, exStyle | WS_EX_LAYERED))
{
if (DWORD err = ::GetLastError())
throw std::system_error(static_cast<int>(err),
std::system_category(),
"SetLayeredWindowFromBitmapResource: Could not set extended window style");
}
// Use RAII ( https://en.wikipedia.org/wiki/Resource_acquisition_is_initialization )
// to cleanup resources even in case of exceptions.
// This greatly simplifies the code because now we don't have to manually cleanup the
// resources at every location in the code where we throw an exception.
struct Resources {
HBITMAP hImage = nullptr;
HGDIOBJ hOldImage = nullptr;
HDC hMemDC = nullptr;
// This destructor will be automatically called before the function
// SetLayeredWindowFromBitmapResource() returns aswell as any locations
// in the code where the "throw" keyword is used to throw an exception.
~Resources()
{
if (hMemDC)
{
if (hOldImage)
::SelectObject(hMemDC, hOldImage);
::DeleteDC(hMemDC);
}
if (hImage)
::DeleteObject(hImage);
}
} res;
// Make it possible to use nullptr as an argument for the hInstance parameter of
// this function. This means we will load the resources from the current executable
// (instead of another DLL).
if (!hInstance)
hInstance = ::GetModuleHandle(nullptr);
// Load bitmap with alpha channel from resource.
// Flag LR_CREATEDIBSECTION is required to create a device-independent bitmap that
// preserves the alpha channel.
res.hImage = reinterpret_cast<HBITMAP>(::LoadImage(
hInstance, MAKEINTRESOURCE(bitmapResourceId), IMAGE_BITMAP,
0, 0, LR_CREATEDIBSECTION));
if (!res.hImage)
{
DWORD err = ::GetLastError();
throw std::system_error(static_cast<int>(err),
std::system_category(),
"SetLayeredWindowFromBitmapResource: Could not load bitmap resource");
}
// Get bitmap information (width, height, etc.)
BITMAP imgInfo{ 0 };
if (!::GetObject(res.hImage, sizeof(imgInfo), &imgInfo))
{
DWORD err = ::GetLastError();
throw std::system_error(static_cast<int>(err),
std::system_category(),
"SetLayeredWindowFromBitmapResource: Could not get bitmap information");
}
if (imgInfo.bmBitsPixel != 32 || imgInfo.bmPlanes != 1)
{
// Use a constant error value here because this is our own error condition.
// Of course GetLastError() wouldn't return anything useful in this case.
DWORD err = ERROR_INVALID_DATA;
throw std::system_error(err, std::system_category(),
"SetLayeredWindowFromBitmapResource: bitmap must be 32 bpp, single plane");
}
// Create a memory DC that will be associated with the image.
// UpdateLayeredWindow() can't use image directly, it must be in a memory DC.
res.hMemDC = ::CreateCompatibleDC(nullptr);
if (!res.hMemDC)
{
DWORD err = ::GetLastError();
throw std::system_error(static_cast<int>(err),
std::system_category(),
"SetLayeredWindowFromBitmapResource: Could not create memory DC");
}
res.hOldImage = ::SelectObject(res.hMemDC, res.hImage);
if (!res.hOldImage)
{
DWORD err = ::GetLastError();
throw std::system_error(static_cast<int>(err),
std::system_category(),
"SetLayeredWindowFromBitmapResource: Could not select bitmap into memory DC");
}
// Assign the image to the child window, making it transparent.
SIZE size{ imgInfo.bmWidth, imgInfo.bmHeight };
POINT ptSrc{ 0, 0 };
BLENDFUNCTION blend{ AC_SRC_OVER, 0, 255, AC_SRC_ALPHA };
if (!::UpdateLayeredWindow(hwnd, nullptr, nullptr, &size, res.hMemDC, &ptSrc,
0, &blend, ULW_ALPHA))
{
DWORD err = ::GetLastError();
throw std::system_error(static_cast<int>(err),
std::system_category(),
"SetLayeredWindowFromBitmapResource: Could not update layered window");
}
// Destructor of res object will cleanup resources here!
}
int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
_In_opt_ HINSTANCE hPrevInstance,
_In_ LPWSTR lpCmdLine,
_In_ int nCmdShow)
{
UNREFERENCED_PARAMETER(hPrevInstance);
UNREFERENCED_PARAMETER(lpCmdLine);
// TODO: Place code here.
RegisterClass1(hInstance);
HWND hWnd = CreateWindowExA(WS_EX_LAYERED, g_szClassName, "Scenes", WS_OVERLAPPEDWINDOW | WS_EX_LAYERED, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL,
hInstance, NULL);
HWND hButton = CreateWindow(TEXT("BUTTON"), TEXT("START EDITING!"), WS_CHILD | WS_VISIBLE | BS_OWNERDRAW | WS_EX_LAYERED, 1, 1,228, 228,
hWnd, (HMENU)CRAPPY, NULL, NULL);
//SetLayeredWindowFromBitmapResource(hButton, ID_THECIRCLE, hInstance);
SetLayeredWindowAttributes(hWnd, 0, 249, LWA_ALPHA);
ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);
SetLayeredWindowFromBitmapResource(hButton, ID_THECIRCLE);
MSG msg;
// Main message loop:
while (GetMessage(&msg, nullptr, 0, 0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return (int) msg.wParam;
}
//
// FUNCTION: RegisterClass1()
//
// PURPOSE: Registers the class
//
// COMMENTS:
//
//
//
//
void RegisterClass1(HINSTANCE hInstance) {
WNDCLASSEXA wc;
wc.cbSize = sizeof(WNDCLASSEX);
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
//wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
wc.hbrBackground = CreateSolidBrush(RGB(255, 0, 0));
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
wc.hInstance = hInstance;
wc.lpfnWndProc = WndProc;
wc.lpszClassName = g_szClassName;
wc.lpszMenuName = "MENU";
wc.style = CS_HREDRAW | CS_VREDRAW;
if (!RegisterClassEx(&wc))
{
MessageBox(NULL, "Window Registration Failed!", "Error!",
MB_ICONEXCLAMATION | MB_OK);
}
}
//
// FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)
//
// PURPOSE: Processes messages for the main window.
//
// WM_COMMAND - process the application menu
// WM_PAINT - Paint the main window
// WM_DESTROY - post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message)
{
case WM_COMMAND:
{
int wmId = LOWORD(wParam);
// Parse the menu selections:
switch (wmId)
{
case IDM_ABOUT:
break;
case IDM_EXIT:
DestroyWindow(hWnd);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
}
break;
case WM_PAINT:
{
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hWnd, &ps);
// TODO: Add any drawing code that uses hdc here...
EndPaint(hWnd, &ps);
}
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}
从Window8开始,WS_EX_LAYERED
可用于子控件。
方法:清单文件需要指定至少 Window 8 兼容性(仅从 Window 8 开始支持子分层)。
参考:Targeting your application for Windows
代码示例:(已删除错误检查)
// Test_CustomButton.cpp : Defines the entry point for the application.
//
#include "framework.h"
#include "Test_CustomButton.h"
#include <commctrl.h>
#include <system_error>
#pragma comment (lib,"Comctl32.lib")
#define MAX_LOADSTRING 100
#define IDC_OWNERDRAWBUTTON 101
#define CRAPPY 567
// Global Variables:
HINSTANCE hInst; // current instance
WCHAR szTitle[MAX_LOADSTRING]; // The title bar text
WCHAR szWindowClass[MAX_LOADSTRING]; // the main window class name
// Forward declarations of functions included in this code module:
ATOM MyRegisterClass(HINSTANCE hInstance);
BOOL InitInstance(HINSTANCE, int);
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
INT_PTR CALLBACK About(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK OwnerDrawButtonProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData);
void SetLayeredWindowFromBitmapResource(
HWND hwnd, UINT bitmapResourceId, HINSTANCE hInstance = nullptr)
{
DWORD exStyle = ::GetWindowLong(hwnd, GWL_EXSTYLE);
SetWindowLong(hwnd, GWL_EXSTYLE, exStyle | WS_EX_LAYERED);
struct Resources {
HBITMAP hImage = nullptr;
HGDIOBJ hOldImage = nullptr;
HDC hMemDC = nullptr;
~Resources()
{
if (hMemDC)
{
if (hOldImage)
::SelectObject(hMemDC, hOldImage);
::DeleteDC(hMemDC);
}
if (hImage)
::DeleteObject(hImage);
}
} res;
if (!hInstance)
hInstance = ::GetModuleHandle(nullptr);
res.hImage = reinterpret_cast<HBITMAP>(::LoadImage(
hInstance, MAKEINTRESOURCE(bitmapResourceId), IMAGE_BITMAP,
0, 0, LR_CREATEDIBSECTION));
BITMAP imgInfo{ 0 };
GetObject(res.hImage, sizeof(imgInfo), &imgInfo);
res.hMemDC = ::CreateCompatibleDC(nullptr);
res.hOldImage = ::SelectObject(res.hMemDC, res.hImage);
// Assign the image to the child window, making it transparent.
SIZE size{ imgInfo.bmWidth, imgInfo.bmHeight };
POINT ptSrc{ 0, 0 };
BLENDFUNCTION blend{ AC_SRC_OVER, 0, 200, AC_SRC_ALPHA };
UpdateLayeredWindow(hwnd, nullptr, nullptr, &size, res.hMemDC, &ptSrc,
0, &blend, ULW_ALPHA);
// Destructor of res object will cleanup resources here!
}
int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
_In_opt_ HINSTANCE hPrevInstance,
_In_ LPWSTR lpCmdLine,
_In_ int nCmdShow)
{
UNREFERENCED_PARAMETER(hPrevInstance);
UNREFERENCED_PARAMETER(lpCmdLine);
LoadStringW(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
LoadStringW(hInstance, IDC_TESTCUSTOMBUTTON, szWindowClass, MAX_LOADSTRING);
MyRegisterClass(hInstance);
if (!InitInstance (hInstance, nCmdShow))
{
return FALSE;
}
HACCEL hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_TESTCUSTOMBUTTON));
MSG msg;
while (GetMessage(&msg, nullptr, 0, 0))
{
if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
return (int) msg.wParam;
}
ATOM MyRegisterClass(HINSTANCE hInstance)
{
WNDCLASSEXW wcex;
wcex.cbSize = sizeof(WNDCLASSEX);
wcex.style = CS_HREDRAW | CS_VREDRAW;
wcex.lpfnWndProc = WndProc;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = 0;
wcex.hInstance = hInstance;
wcex.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_TESTCUSTOMBUTTON));
wcex.hCursor = LoadCursor(nullptr, IDC_ARROW);
wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wcex.lpszMenuName = MAKEINTRESOURCEW(IDC_TESTCUSTOMBUTTON);
wcex.lpszClassName = szWindowClass;
wcex.hIconSm = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));
return RegisterClassExW(&wcex);
}
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
hInst = hInstance; // Store instance handle in our global variable
HWND hWnd = CreateWindowW(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, nullptr, nullptr, hInstance, nullptr);
ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);
if (!hWnd)
{
return FALSE;
}
ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);
return TRUE;
}
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message)
{
case WM_CREATE:
{
HWND hButton = CreateWindowEx(0, L"button", NULL, WS_CHILD | WS_VISIBLE | BS_OWNERDRAW, 150, 50, 80, 80, hWnd, (HMENU)IDC_OWNERDRAWBUTTON, hInst, NULL);
SetWindowSubclass(hButton, &OwnerDrawButtonProc, IDC_OWNERDRAWBUTTON, 0);
}
break;
case WM_COMMAND:
{
int wmId = LOWORD(wParam);
// Parse the menu selections:
switch (wmId)
{
case IDM_ABOUT:
DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
break;
case IDM_EXIT:
DestroyWindow(hWnd);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
}
break;
case WM_PAINT:
{
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hWnd, &ps);
// Used be test
HPEN hPen = CreatePen(PS_SOLID, 2, RGB(255, 0, 0));
SelectObject(hdc, hPen);
MoveToEx(hdc, 150, 150, NULL);
LineTo(hdc, 200, 60);
LineTo(hdc, 250, 150);
LineTo(hdc, 150, 150);
EndPaint(hWnd, &ps);
}
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}
// Message handler for about box.
INT_PTR CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
UNREFERENCED_PARAMETER(lParam);
switch (message)
{
case WM_INITDIALOG:
return (INT_PTR)TRUE;
case WM_COMMAND:
if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL)
{
EndDialog(hDlg, LOWORD(wParam));
return (INT_PTR)TRUE;
}
break;
}
return (INT_PTR)FALSE;
}
LRESULT CALLBACK OwnerDrawButtonProc(HWND hWnd, UINT uMsg, WPARAM wParam,
LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
switch (uMsg)
{
case WM_PAINT:
{
RECT rc;
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hWnd, &ps);
SetLayeredWindowFromBitmapResource(hWnd, IDB_BITMAP1);
EndPaint(hWnd, &ps);
return 0;
}
case WM_NCDESTROY:
RemoveWindowSubclass(hWnd, &OwnerDrawButtonProc, 1);
break;
}
return DefSubclassProc(hWnd, uMsg, wParam, lParam);
}
调试:
注:
我测试的时候发现需要满足以下条件:
要加载的图像必须是 32 bpp、自上而下的位图 预乘 alpha 通道。
这是我的 32 bpp image 测试。
开头说了,需要添加manifest文件,可以 自己创建一个 .manifest 文件。然后在编译器中添加。
只需要给子控件添加
WS_EX_LAYERED
样式, 因为你的要求是让按钮透明。
在我的例子中,所提供的代码不起作用,因为它抛出异常并且我没有正确添加清单文件。我想注意一些事情:
用 gimp 制作的位图图像不工作;使用我在问题中链接的线程中建议的内容,即 PixelFormer。在 Pixel Former 中转到 "file",然后选择 "Import" 并选择您的文件(在我的例子中它是透明的圆圈 png)。接下来转到 "export" 并选择位图 bmp(它会说 windows 位图)。一旦你这样做了,已经 A8:R8:G8:B8 (32bpp) 将被选中,接下来你必须选中最后两个框 "Premultiplied Alpha" 和 "Top-down row order"。必须要说的是,图像确实有一个 alpha 通道,而且它是透明的。不要被愚弄,打开画图,你看到黑色背景,你认为透明度不存在——透明就在那里工作……如果你在 photoshop(我认为)或复杂的软件中打开它图像编辑程序,您将在图像中看到透明背景。
manifest.xml
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
<compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
<application>
<!-- Windows 10 -->
<supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}"/>
<!-- Windows 8.1 -->
<supportedOS Id="{1f676c76-80e1-4239-95bb-83d0f6d0da78}"/>
<!-- Windows 8 -->
<supportedOS Id="{4a2f28e3-53b9-4441-ba9c-d69d4a4a6e38}"/>
<!-- Windows 7 -->
<supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}"/>
<!-- Windows Vista -->
<supportedOS Id="{e2011457-1546-43c5-a5fe-008deee3d3f0}"/>
</application>
</compatibility>
<dependency>
<dependentAssembly>
<assemblyIdentity
type="win32"
name="Microsoft.Windows.Common-Controls"
version="6.0.0.0"
processorArchitecture="*"
publicKeyToken="6595b64144ccf1df"
language="*"
/>
</dependentAssembly>
</dependency>
</assembly>
复制上面的内容并保存为manifest.xml
我要注意的另一件事是添加一个清单条目文件:在我的例子中,我必须将它添加到 C:\Users\Rubel\source\repos\CustomButton2\CustomButton2 所以无论谁在将来查看这个,都将其替换为你的项目目录;例如,C:\Users\blah\source\repos\blah\blah(带有你的东西名称的废话)。将您的清单文件粘贴到那里(在目录中)。
然后您必须将其添加到 visual studio。您可以通过在解决方案资源管理器中右键单击您的项目(在我的例子中是 CustomButton2 )并转到 "Input and Output" 中的 "Manifest Tool" 来执行此操作。在这里输入 "Additional Manifest Files" 你的清单文件的路径(在我的例子中它是 manifest.xml 但如果你跟着,那么你的路径也应该是这种情况)
就是这样,如果您使用提供的代码 (Strive Sun - MSFT),它应该可以工作。 如果有人感兴趣,这是我的最终代码:
// CustomButton2.cpp : Defines the entry point for the application.
//
#include "framework.h"
#include "CustomButton2.h"
#include <commctrl.h>
#include <gdiplus.h>
#include <system_error>
#define MAX_LOADSTRING 100
#define CRAPPY 567
#define IDC_OWNERDRAWBUTTON 101
#pragma comment(linker,"/manifestdependency:\"type='win32' name='Microsoft.Windows.Common-Controls' " "version='6.0.0.0' processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"")
// Global Variables:
HINSTANCE hInst; // current instance
WCHAR szTitle[MAX_LOADSTRING]; // The title bar text
WCHAR szWindowClass[MAX_LOADSTRING]; // the main window class name
const char g_szClassName[] = "MyClassName";
// Forward declarations of functions included in this code module:
ATOM MyRegisterClass(HINSTANCE hInstance);
void RegisterClass1(HINSTANCE);
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK OwnerDrawButtonProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData);
void SetLayeredWindowFromBitmapResource(
HWND hwnd, UINT bitmapResourceId, HINSTANCE hInstance = nullptr)
{
DWORD exStyle = ::GetWindowLong(hwnd, GWL_EXSTYLE);
SetWindowLong(hwnd, GWL_EXSTYLE, exStyle | WS_EX_LAYERED);
struct Resources {
HBITMAP hImage = nullptr;
HGDIOBJ hOldImage = nullptr;
HDC hMemDC = nullptr;
~Resources()
{
if (hMemDC)
{
if (hOldImage)
::SelectObject(hMemDC, hOldImage);
::DeleteDC(hMemDC);
}
if (hImage)
::DeleteObject(hImage);
}
} res;
if (!hInstance)
hInstance = ::GetModuleHandle(nullptr);
res.hImage = reinterpret_cast<HBITMAP>(::LoadImage(
hInstance, MAKEINTRESOURCE(bitmapResourceId), IMAGE_BITMAP,
0, 0, LR_CREATEDIBSECTION));
BITMAP imgInfo{ 0 };
GetObject(res.hImage, sizeof(imgInfo), &imgInfo);
res.hMemDC = ::CreateCompatibleDC(nullptr);
res.hOldImage = ::SelectObject(res.hMemDC, res.hImage);
// Assign the image to the child window, making it transparent.
SIZE size{ imgInfo.bmWidth, imgInfo.bmHeight };
POINT ptSrc{ 0, 0 };
BLENDFUNCTION blend{ AC_SRC_OVER, 0, 200, AC_SRC_ALPHA };
UpdateLayeredWindow(hwnd, nullptr, nullptr, &size, res.hMemDC, &ptSrc,
0, &blend, ULW_ALPHA);
// Destructor of res object will cleanup resources here!
}
int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
_In_opt_ HINSTANCE hPrevInstance,
_In_ LPWSTR lpCmdLine,
_In_ int nCmdShow)
{
UNREFERENCED_PARAMETER(hPrevInstance);
UNREFERENCED_PARAMETER(lpCmdLine);
// TODO: Place code here.
RegisterClass1(hInstance);
HWND hWnd = CreateWindowExA(WS_EX_LAYERED, g_szClassName, "Scenes", WS_OVERLAPPEDWINDOW | WS_EX_LAYERED, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL,
hInstance, NULL);
HWND hButton = CreateWindow(TEXT("BUTTON"), TEXT("START EDITING!"), WS_CHILD | WS_VISIBLE | BS_OWNERDRAW | WS_EX_LAYERED, 1, 1,228, 228,
hWnd, (HMENU)CRAPPY, NULL, NULL);
SetWindowSubclass(hButton, &OwnerDrawButtonProc, IDC_OWNERDRAWBUTTON, 0);
//SetLayeredWindowFromBitmapResource(hButton, ID_THECIRCLE, hInstance);
SetLayeredWindowAttributes(hWnd, 0, 249, LWA_ALPHA);
ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);
//SetLayeredWindowFromBitmapResource(hButton, ID_THECIRCLE);
MSG msg;
// Main message loop:
while (GetMessage(&msg, nullptr, 0, 0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return (int) msg.wParam;
}
//
// FUNCTION: RegisterClass1()
//
// PURPOSE: Registers the class
//
// COMMENTS:
//
//
//
//
void RegisterClass1(HINSTANCE hInstance) {
WNDCLASSEXA wc;
wc.cbSize = sizeof(WNDCLASSEX);
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
//wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
wc.hbrBackground = CreateSolidBrush(RGB(255, 0, 0));
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
wc.hInstance = hInstance;
wc.lpfnWndProc = WndProc;
wc.lpszClassName = g_szClassName;
wc.lpszMenuName = "MENU";
wc.style = CS_HREDRAW | CS_VREDRAW;
if (!RegisterClassEx(&wc))
{
MessageBox(NULL, "Window Registration Failed!", "Error!",
MB_ICONEXCLAMATION | MB_OK);
}
}
//
// FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)
//
// PURPOSE: Processes messages for the main window.
//
// WM_COMMAND - process the application menu
// WM_PAINT - Paint the main window
// WM_DESTROY - post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message)
{
case WM_COMMAND:
{
int wmId = LOWORD(wParam);
// Parse the menu selections:
switch (wmId)
{
case IDM_ABOUT:
break;
case IDM_EXIT:
DestroyWindow(hWnd);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
}
break;
case WM_PAINT:
{
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hWnd, &ps);
// TODO: Add any drawing code that uses hdc here...
EndPaint(hWnd, &ps);
}
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}
LRESULT CALLBACK OwnerDrawButtonProc(HWND hWnd, UINT uMsg, WPARAM wParam,
LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
switch (uMsg)
{
case WM_PAINT:
{
RECT rc;
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hWnd, &ps);
SetLayeredWindowFromBitmapResource(hWnd, ID_THECIRCLE);
EndPaint(hWnd, &ps);
return 0;
}
case WM_NCDESTROY:
RemoveWindowSubclass(hWnd, &OwnerDrawButtonProc, 1);
break;
}
return DefSubclassProc(hWnd, uMsg, wParam, lParam);
}
申请运行:
我知道这很冗长,但我希望遇到此问题的任何人都能轻松理解,以便他们知道如何去做。