基本 Win32 WebView2 示例不能在纯 C 中工作
Basic Win32 WebView2 example not working in pure C
最近我遇到了一个新问题：使用 Microsoft 的 WebView2 库的一个非常简单的代码如果编译为 C++ 而不是 C，则可以正常工作。可能是什么导致了这个问题？我尝试了各种修复，比如使用旧版本的 WebView2 库，使用 Edge Canary 或 beta 或不同版本的 WebView2 运行时，它只是拒绝工作。
这里是C:
中的示例代码
#include <initguid.h>
#include <Windows.h>
#include <stdio.h>
#include <conio.h>
#include <shlwapi.h>
#pragma comment(lib, "Shlwapi.lib")
#include <Shlobj_core.h>
#include "WebView2.h"
#define APPLICATION_NAME TEXT("WebView2")
#define error_printf printf
ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler* envHandler;
ICoreWebView2CreateCoreWebView2ControllerCompletedHandler* completedHandler;
HWND hWnd = NULL;
ICoreWebView2Controller* webviewController = NULL;
ICoreWebView2* webviewWindow = NULL;
BOOL bEnvCreated = FALSE;
ULONG HandlerRefCount = 0;
ULONG HandlerAddRef(IUnknown* This)
{
return ++HandlerRefCount;
}
ULONG HandlerRelease(IUnknown* This)
{
--HandlerRefCount;
if (HandlerRefCount == 0)
{
if (completedHandler)
{
free(completedHandler->lpVtbl);
free(completedHandler);
}
if (envHandler)
{
free(envHandler->lpVtbl);
free(envHandler);
}
}
return HandlerRefCount;
}
HRESULT HandlerQueryInterface(
IUnknown* This,
IID* riid,
void** ppvObject
)
{
*ppvObject = This;
HandlerAddRef(This);
return S_OK;
}
HRESULT HandlerInvoke(
IUnknown* This,
HRESULT errorCode,
void* arg
)
{
if (!bEnvCreated)
{
bEnvCreated = TRUE;
char ch;
completedHandler = malloc(sizeof(ICoreWebView2CreateCoreWebView2ControllerCompletedHandler));
if (!completedHandler)
{
error_printf(
"%s:%d: %s (0x%x).\n",
__FILE__,
__LINE__,
"Cannot allocate ICoreWebView2CreateCoreWebView2ControllerCompletedHandler",
GetLastError()
);
ch = _getch();
return GetLastError();
}
completedHandler->lpVtbl = malloc(sizeof(ICoreWebView2CreateCoreWebView2ControllerCompletedHandlerVtbl));
if (!completedHandler->lpVtbl)
{
error_printf(
"%s:%d: %s (0x%x).\n",
__FILE__,
__LINE__,
"Cannot allocate ICoreWebView2CreateCoreWebView2ControllerCompletedHandlerVtbl",
GetLastError()
);
ch = _getch();
return GetLastError();
}
completedHandler->lpVtbl->AddRef = HandlerAddRef;
completedHandler->lpVtbl->Release = HandlerRelease;
completedHandler->lpVtbl->QueryInterface = HandlerQueryInterface;
completedHandler->lpVtbl->Invoke = HandlerInvoke;
ICoreWebView2Environment* env = arg;
env->lpVtbl->CreateCoreWebView2Controller(
env,
hWnd,
completedHandler
);
}
else
{
ICoreWebView2Controller* controller = arg;
if (controller != NULL) {
webviewController = controller;
webviewController->lpVtbl->get_CoreWebView2(
webviewController,
&webviewWindow
);
}
ICoreWebView2Settings* Settings;
webviewWindow->lpVtbl->get_Settings(
webviewWindow,
&Settings
);
Settings->lpVtbl->put_IsScriptEnabled(
Settings,
TRUE
);
Settings->lpVtbl->put_AreDefaultScriptDialogsEnabled(
Settings,
TRUE
);
Settings->lpVtbl->put_IsWebMessageEnabled(
Settings,
TRUE
);
Settings->lpVtbl->put_AreDevToolsEnabled(
Settings,
FALSE
);
Settings->lpVtbl->put_AreDefaultContextMenusEnabled(
Settings,
TRUE
);
Settings->lpVtbl->put_IsStatusBarEnabled(
Settings,
TRUE
);
RECT bounds;
GetClientRect(hWnd, &bounds);
webviewController->lpVtbl->put_Bounds(
webviewController,
bounds
);
webviewWindow->lpVtbl->Navigate(
webviewWindow,
L"https://google.com/"
);
}
return S_OK;
}
LRESULT CALLBACK WindowProc(
_In_ HWND hWnd,
_In_ UINT uMsg,
_In_ WPARAM wParam,
_In_ LPARAM lParam
)
{
switch (uMsg)
{
/*case WM_NCCALCSIZE:
{
return 0;
}*/
case WM_DPICHANGED:
{
RECT* const newWindowSize = (RECT*)(lParam);
SetWindowPos(
hWnd,
NULL,
newWindowSize->left,
newWindowSize->top,
newWindowSize->right - newWindowSize->left,
newWindowSize->bottom - newWindowSize->top,
SWP_NOZORDER | SWP_NOACTIVATE);
return TRUE;
}
case WM_SIZE:
{
if (webviewController != NULL) {
RECT bounds;
GetClientRect(hWnd, &bounds);
webviewController->lpVtbl->put_Bounds(
webviewController,
bounds
);
};
break;
}
default:
{
return DefWindowProc(
hWnd,
uMsg,
wParam,
lParam
);
}
}
return 0;
}
int WINAPI wWinMain(
_In_ HINSTANCE hInstance,
_In_opt_ HINSTANCE hPrevInstance,
_In_ LPWSTR lpCmdLine,
_In_ int nShowCmd
)
{
int ch;
FILE* conout;
AllocConsole();
freopen_s(
&conout,
"CONOUT$",
"w",
stdout
);
HRESULT hr;
if (!SetProcessDpiAwarenessContext(
DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2
))
{
error_printf(
"%s:%d: %s (0x%x).\n",
__FILE__,
__LINE__,
"SetProcessDpiAwarenessContext",
GetLastError()
);
ch = _getch();
return GetLastError();
}
hr = CoInitialize(NULL);
if (FAILED(hr))
{
error_printf(
"%s:%d: %s (0x%x).\n",
__FILE__,
__LINE__,
"CoInitialize",
hr
);
ch = _getch();
return hr;
}
WNDCLASS wndClass = { 0 };
wndClass.style = CS_HREDRAW | CS_VREDRAW;
wndClass.lpfnWndProc = WindowProc;
wndClass.cbClsExtra = 0;
wndClass.cbWndExtra = 0;
wndClass.hInstance = hInstance;
wndClass.hCursor = LoadCursor(NULL, IDC_ARROW);
wndClass.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
wndClass.lpszMenuName = NULL;
wndClass.lpszClassName = APPLICATION_NAME;
hWnd = CreateWindowEx(
0,
(LPCWSTR)(
MAKEINTATOM(
RegisterClass(&wndClass)
)
),
APPLICATION_NAME,
WS_OVERLAPPEDWINDOW,
100, 100, 800, 800,
NULL,
NULL,
hInstance,
NULL
);
if (!hWnd)
{
error_printf(
"%s:%d: %s (0x%x).\n",
__FILE__,
__LINE__,
"CreateWindowEx",
GetLastError()
);
ch = _getch();
return GetLastError();
}
ShowWindow(hWnd, nShowCmd);
envHandler = malloc(sizeof(ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler));
if (!envHandler)
{
error_printf(
"%s:%d: %s (0x%x).\n",
__FILE__,
__LINE__,
"Cannot allocate ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler",
GetLastError()
);
ch = _getch();
return GetLastError();
}
envHandler->lpVtbl = malloc(sizeof(ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandlerVtbl));
if (!envHandler->lpVtbl)
{
error_printf(
"%s:%d: %s (0x%x).\n",
__FILE__,
__LINE__,
"Cannot allocate ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandlerVtbl",
GetLastError()
);
ch = _getch();
return GetLastError();
}
envHandler->lpVtbl->AddRef = HandlerAddRef;
envHandler->lpVtbl->Release = HandlerRelease;
envHandler->lpVtbl->QueryInterface = HandlerQueryInterface;
envHandler->lpVtbl->Invoke = HandlerInvoke;
UpdateWindow(hWnd);
CreateCoreWebView2EnvironmentWithOptions(
NULL,
NULL,
NULL,
envHandler
);
MSG msg;
BOOL bRet;
while ((bRet = GetMessage(
&msg,
NULL,
0,
0)) != 0)
{
// An error occured
if (bRet == -1)
{
break;
}
else
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
return 0;
}
如您所见，我只是在适当的地方使用了 lpVtbl 并提供了适当的回调。代码在 C++ 中更加紧凑：
#include <Windows.h>
#include <stdio.h>
#include <wrl.h>
#include <wil/com.h>
#include "WebView2.h"
#define APPLICATION_NAME TEXT("WebView2")
static wil::com_ptr<ICoreWebView2Controller> webviewController;
static wil::com_ptr<ICoreWebView2> webviewWindow;
LRESULT CALLBACK WindowProc(
_In_ HWND hwnd,
_In_ UINT uMsg,
_In_ WPARAM wParam,
_In_ LPARAM lParam
)
{
switch (uMsg)
{
case WM_DPICHANGED:
{
RECT* const newWindowSize = (RECT*)(lParam);
SetWindowPos(hwnd,
NULL,
newWindowSize->left,
newWindowSize->top,
newWindowSize->right - newWindowSize->left,
newWindowSize->bottom - newWindowSize->top,
SWP_NOZORDER | SWP_NOACTIVATE);
return TRUE;
}
case WM_SIZE:
{
if (webviewController != NULL) {
RECT bounds;
GetClientRect(hwnd, &bounds);
webviewController->put_Bounds(bounds);
};
break;
}
case WM_DESTROY:
{
PostQuitMessage(0);
break;
}
default:
{
return DefWindowProc(
hwnd,
uMsg,
wParam,
lParam
);
}
}
return 0;
}
int WINAPI wWinMain(
HINSTANCE hInstance,
HINSTANCE hPrevInstance,
PWSTR pCmdLine,
int nCmdShow
)
{
SetProcessDpiAwarenessContext(
DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2
);
WNDCLASS wndClass = { 0 };
wndClass.style = CS_HREDRAW | CS_VREDRAW;
wndClass.lpfnWndProc = WindowProc;
wndClass.cbClsExtra = 0;
wndClass.cbWndExtra = 0;
wndClass.hInstance = hInstance;
wndClass.hCursor = LoadCursor(NULL, IDC_ARROW);
wndClass.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
wndClass.lpszMenuName = NULL;
wndClass.lpszClassName = APPLICATION_NAME;
RegisterClass(&wndClass);
HWND hWnd = CreateWindowEx(
0,
APPLICATION_NAME,
APPLICATION_NAME,
WS_OVERLAPPEDWINDOW,
100, 100, 800, 800,
NULL,
NULL,
hInstance,
NULL
);
ShowWindow(
hWnd,
nCmdShow
);
UpdateWindow(hWnd);
CreateCoreWebView2EnvironmentWithOptions(NULL, NULL, NULL,
Microsoft::WRL::Callback<ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler>(
[hWnd](HRESULT result, ICoreWebView2Environment* env) -> HRESULT {
// Create a CoreWebView2Controller and get the associated CoreWebView2 whose parent is the main window hWnd
env->CreateCoreWebView2Controller(hWnd, Microsoft::WRL::Callback<ICoreWebView2CreateCoreWebView2ControllerCompletedHandler>(
[hWnd](HRESULT result, ICoreWebView2Controller* controller) -> HRESULT {
if (controller != nullptr) {
webviewController = controller;
webviewController->get_CoreWebView2(&webviewWindow);
}
// Add a few settings for the webview
// The demo step is redundant since the values are the default settings
ICoreWebView2Settings* Settings;
webviewWindow->get_Settings(&Settings);
Settings->put_IsScriptEnabled(TRUE);
Settings->put_AreDefaultScriptDialogsEnabled(TRUE);
Settings->put_IsWebMessageEnabled(TRUE);
Settings->put_AreDevToolsEnabled(FALSE);
//Settings->put_AreDefaultContextMenusEnabled(FALSE);
Settings->put_IsStatusBarEnabled(FALSE);
// Resize WebView to fit the bounds of the parent window
RECT bounds;
GetClientRect(hWnd, &bounds);
webviewController->put_Bounds(bounds);
webviewController->put_ZoomFactor(0.8);
// Schedule an async task to navigate to Bing
webviewWindow->Navigate(HOME_PAGE);
// Step 4 - Navigation events
// Step 5 - Scripting
// Step 6 - Communication between host and web content
return S_OK;
}).Get());
return S_OK;
}).Get());
MSG msg;
BOOL bRet;
while ((bRet = GetMessage(
&msg,
NULL,
0,
0)) != 0)
{
// An error occured
if (bRet == -1)
{
break;
}
else
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
return (int)msg.wParam;
}
既然我现在偶然发现了这个问题，我真的很好奇是什么原因造成的。为什么它最终很重要？感谢您的指点。
无效表示网页没有显示。 window 为空白。 window.
上居然没有显示WebView2
编辑：
wil::com_ptr实际上是什么？如果我改变这个：
static wil::com_ptr<ICoreWebView2Controller> webviewController;
static wil::com_ptr<ICoreWebView2> webviewWindow;
为此：
static ICoreWebView2Controller* webviewController;
static ICoreWebView2* webviewWindow;
在C++中，我打破了它。为什么？只是为什么？ （我用独立的 类 替换了回调 Microsoft::WRL::Callback，当然，它仍然有效，但是摆脱 COM 指针并使用常规指针会破坏它。为什么...？
解决方案很简单，如果真的花一分钟时间看一下代码的正确性和逻辑，而不是建议泛型和注释只是为了让跳线有一些字节可以携带。这部分必须稍微修改一下：因为我在函数 returns 之后使用 controller，并且没有使用智能指针，所以我必须增加它的引用计数，以便库知道我使用它而不是在 Invoke 函数体执行后释放它。当然，当你在使用智能指针的版本中进行赋值时，这是在后台自动完成的。不幸的是，我忽略了这一点，没有意识到会发生这种情况。像这样的事情是我用 C 编写这些端口的原因，这样我就可以深入了解并更好地理解这些东西从上到下是如何工作的。没有实际原因的“无法完成”对我来说不是一个有效的答案。
无论如何，这里是固定版本：
if (controller != NULL) {
webviewController = controller;
webviewController->lpVtbl->get_CoreWebView2(
webviewController,
&webviewWindow
);
webviewController->lpVtbl->AddRef(webviewController); // <-- here, increase the reference count for the webviewController
}
就是这样。非常感谢帮助我的人：https://github.com/MicrosoftEdge/WebView2Feedback/issues/1124
最近我遇到了一个新问题：使用 Microsoft 的 WebView2 库的一个非常简单的代码如果编译为 C++ 而不是 C，则可以正常工作。可能是什么导致了这个问题？我尝试了各种修复，比如使用旧版本的 WebView2 库，使用 Edge Canary 或 beta 或不同版本的 WebView2 运行时，它只是拒绝工作。
这里是C:
中的示例代码#include <initguid.h>
#include <Windows.h>
#include <stdio.h>
#include <conio.h>
#include <shlwapi.h>
#pragma comment(lib, "Shlwapi.lib")
#include <Shlobj_core.h>
#include "WebView2.h"
#define APPLICATION_NAME TEXT("WebView2")
#define error_printf printf
ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler* envHandler;
ICoreWebView2CreateCoreWebView2ControllerCompletedHandler* completedHandler;
HWND hWnd = NULL;
ICoreWebView2Controller* webviewController = NULL;
ICoreWebView2* webviewWindow = NULL;
BOOL bEnvCreated = FALSE;
ULONG HandlerRefCount = 0;
ULONG HandlerAddRef(IUnknown* This)
{
return ++HandlerRefCount;
}
ULONG HandlerRelease(IUnknown* This)
{
--HandlerRefCount;
if (HandlerRefCount == 0)
{
if (completedHandler)
{
free(completedHandler->lpVtbl);
free(completedHandler);
}
if (envHandler)
{
free(envHandler->lpVtbl);
free(envHandler);
}
}
return HandlerRefCount;
}
HRESULT HandlerQueryInterface(
IUnknown* This,
IID* riid,
void** ppvObject
)
{
*ppvObject = This;
HandlerAddRef(This);
return S_OK;
}
HRESULT HandlerInvoke(
IUnknown* This,
HRESULT errorCode,
void* arg
)
{
if (!bEnvCreated)
{
bEnvCreated = TRUE;
char ch;
completedHandler = malloc(sizeof(ICoreWebView2CreateCoreWebView2ControllerCompletedHandler));
if (!completedHandler)
{
error_printf(
"%s:%d: %s (0x%x).\n",
__FILE__,
__LINE__,
"Cannot allocate ICoreWebView2CreateCoreWebView2ControllerCompletedHandler",
GetLastError()
);
ch = _getch();
return GetLastError();
}
completedHandler->lpVtbl = malloc(sizeof(ICoreWebView2CreateCoreWebView2ControllerCompletedHandlerVtbl));
if (!completedHandler->lpVtbl)
{
error_printf(
"%s:%d: %s (0x%x).\n",
__FILE__,
__LINE__,
"Cannot allocate ICoreWebView2CreateCoreWebView2ControllerCompletedHandlerVtbl",
GetLastError()
);
ch = _getch();
return GetLastError();
}
completedHandler->lpVtbl->AddRef = HandlerAddRef;
completedHandler->lpVtbl->Release = HandlerRelease;
completedHandler->lpVtbl->QueryInterface = HandlerQueryInterface;
completedHandler->lpVtbl->Invoke = HandlerInvoke;
ICoreWebView2Environment* env = arg;
env->lpVtbl->CreateCoreWebView2Controller(
env,
hWnd,
completedHandler
);
}
else
{
ICoreWebView2Controller* controller = arg;
if (controller != NULL) {
webviewController = controller;
webviewController->lpVtbl->get_CoreWebView2(
webviewController,
&webviewWindow
);
}
ICoreWebView2Settings* Settings;
webviewWindow->lpVtbl->get_Settings(
webviewWindow,
&Settings
);
Settings->lpVtbl->put_IsScriptEnabled(
Settings,
TRUE
);
Settings->lpVtbl->put_AreDefaultScriptDialogsEnabled(
Settings,
TRUE
);
Settings->lpVtbl->put_IsWebMessageEnabled(
Settings,
TRUE
);
Settings->lpVtbl->put_AreDevToolsEnabled(
Settings,
FALSE
);
Settings->lpVtbl->put_AreDefaultContextMenusEnabled(
Settings,
TRUE
);
Settings->lpVtbl->put_IsStatusBarEnabled(
Settings,
TRUE
);
RECT bounds;
GetClientRect(hWnd, &bounds);
webviewController->lpVtbl->put_Bounds(
webviewController,
bounds
);
webviewWindow->lpVtbl->Navigate(
webviewWindow,
L"https://google.com/"
);
}
return S_OK;
}
LRESULT CALLBACK WindowProc(
_In_ HWND hWnd,
_In_ UINT uMsg,
_In_ WPARAM wParam,
_In_ LPARAM lParam
)
{
switch (uMsg)
{
/*case WM_NCCALCSIZE:
{
return 0;
}*/
case WM_DPICHANGED:
{
RECT* const newWindowSize = (RECT*)(lParam);
SetWindowPos(
hWnd,
NULL,
newWindowSize->left,
newWindowSize->top,
newWindowSize->right - newWindowSize->left,
newWindowSize->bottom - newWindowSize->top,
SWP_NOZORDER | SWP_NOACTIVATE);
return TRUE;
}
case WM_SIZE:
{
if (webviewController != NULL) {
RECT bounds;
GetClientRect(hWnd, &bounds);
webviewController->lpVtbl->put_Bounds(
webviewController,
bounds
);
};
break;
}
default:
{
return DefWindowProc(
hWnd,
uMsg,
wParam,
lParam
);
}
}
return 0;
}
int WINAPI wWinMain(
_In_ HINSTANCE hInstance,
_In_opt_ HINSTANCE hPrevInstance,
_In_ LPWSTR lpCmdLine,
_In_ int nShowCmd
)
{
int ch;
FILE* conout;
AllocConsole();
freopen_s(
&conout,
"CONOUT$",
"w",
stdout
);
HRESULT hr;
if (!SetProcessDpiAwarenessContext(
DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2
))
{
error_printf(
"%s:%d: %s (0x%x).\n",
__FILE__,
__LINE__,
"SetProcessDpiAwarenessContext",
GetLastError()
);
ch = _getch();
return GetLastError();
}
hr = CoInitialize(NULL);
if (FAILED(hr))
{
error_printf(
"%s:%d: %s (0x%x).\n",
__FILE__,
__LINE__,
"CoInitialize",
hr
);
ch = _getch();
return hr;
}
WNDCLASS wndClass = { 0 };
wndClass.style = CS_HREDRAW | CS_VREDRAW;
wndClass.lpfnWndProc = WindowProc;
wndClass.cbClsExtra = 0;
wndClass.cbWndExtra = 0;
wndClass.hInstance = hInstance;
wndClass.hCursor = LoadCursor(NULL, IDC_ARROW);
wndClass.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
wndClass.lpszMenuName = NULL;
wndClass.lpszClassName = APPLICATION_NAME;
hWnd = CreateWindowEx(
0,
(LPCWSTR)(
MAKEINTATOM(
RegisterClass(&wndClass)
)
),
APPLICATION_NAME,
WS_OVERLAPPEDWINDOW,
100, 100, 800, 800,
NULL,
NULL,
hInstance,
NULL
);
if (!hWnd)
{
error_printf(
"%s:%d: %s (0x%x).\n",
__FILE__,
__LINE__,
"CreateWindowEx",
GetLastError()
);
ch = _getch();
return GetLastError();
}
ShowWindow(hWnd, nShowCmd);
envHandler = malloc(sizeof(ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler));
if (!envHandler)
{
error_printf(
"%s:%d: %s (0x%x).\n",
__FILE__,
__LINE__,
"Cannot allocate ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler",
GetLastError()
);
ch = _getch();
return GetLastError();
}
envHandler->lpVtbl = malloc(sizeof(ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandlerVtbl));
if (!envHandler->lpVtbl)
{
error_printf(
"%s:%d: %s (0x%x).\n",
__FILE__,
__LINE__,
"Cannot allocate ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandlerVtbl",
GetLastError()
);
ch = _getch();
return GetLastError();
}
envHandler->lpVtbl->AddRef = HandlerAddRef;
envHandler->lpVtbl->Release = HandlerRelease;
envHandler->lpVtbl->QueryInterface = HandlerQueryInterface;
envHandler->lpVtbl->Invoke = HandlerInvoke;
UpdateWindow(hWnd);
CreateCoreWebView2EnvironmentWithOptions(
NULL,
NULL,
NULL,
envHandler
);
MSG msg;
BOOL bRet;
while ((bRet = GetMessage(
&msg,
NULL,
0,
0)) != 0)
{
// An error occured
if (bRet == -1)
{
break;
}
else
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
return 0;
}
如您所见，我只是在适当的地方使用了 lpVtbl 并提供了适当的回调。代码在 C++ 中更加紧凑：
#include <Windows.h>
#include <stdio.h>
#include <wrl.h>
#include <wil/com.h>
#include "WebView2.h"
#define APPLICATION_NAME TEXT("WebView2")
static wil::com_ptr<ICoreWebView2Controller> webviewController;
static wil::com_ptr<ICoreWebView2> webviewWindow;
LRESULT CALLBACK WindowProc(
_In_ HWND hwnd,
_In_ UINT uMsg,
_In_ WPARAM wParam,
_In_ LPARAM lParam
)
{
switch (uMsg)
{
case WM_DPICHANGED:
{
RECT* const newWindowSize = (RECT*)(lParam);
SetWindowPos(hwnd,
NULL,
newWindowSize->left,
newWindowSize->top,
newWindowSize->right - newWindowSize->left,
newWindowSize->bottom - newWindowSize->top,
SWP_NOZORDER | SWP_NOACTIVATE);
return TRUE;
}
case WM_SIZE:
{
if (webviewController != NULL) {
RECT bounds;
GetClientRect(hwnd, &bounds);
webviewController->put_Bounds(bounds);
};
break;
}
case WM_DESTROY:
{
PostQuitMessage(0);
break;
}
default:
{
return DefWindowProc(
hwnd,
uMsg,
wParam,
lParam
);
}
}
return 0;
}
int WINAPI wWinMain(
HINSTANCE hInstance,
HINSTANCE hPrevInstance,
PWSTR pCmdLine,
int nCmdShow
)
{
SetProcessDpiAwarenessContext(
DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2
);
WNDCLASS wndClass = { 0 };
wndClass.style = CS_HREDRAW | CS_VREDRAW;
wndClass.lpfnWndProc = WindowProc;
wndClass.cbClsExtra = 0;
wndClass.cbWndExtra = 0;
wndClass.hInstance = hInstance;
wndClass.hCursor = LoadCursor(NULL, IDC_ARROW);
wndClass.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
wndClass.lpszMenuName = NULL;
wndClass.lpszClassName = APPLICATION_NAME;
RegisterClass(&wndClass);
HWND hWnd = CreateWindowEx(
0,
APPLICATION_NAME,
APPLICATION_NAME,
WS_OVERLAPPEDWINDOW,
100, 100, 800, 800,
NULL,
NULL,
hInstance,
NULL
);
ShowWindow(
hWnd,
nCmdShow
);
UpdateWindow(hWnd);
CreateCoreWebView2EnvironmentWithOptions(NULL, NULL, NULL,
Microsoft::WRL::Callback<ICoreWebView2CreateCoreWebView2EnvironmentCompletedHandler>(
[hWnd](HRESULT result, ICoreWebView2Environment* env) -> HRESULT {
// Create a CoreWebView2Controller and get the associated CoreWebView2 whose parent is the main window hWnd
env->CreateCoreWebView2Controller(hWnd, Microsoft::WRL::Callback<ICoreWebView2CreateCoreWebView2ControllerCompletedHandler>(
[hWnd](HRESULT result, ICoreWebView2Controller* controller) -> HRESULT {
if (controller != nullptr) {
webviewController = controller;
webviewController->get_CoreWebView2(&webviewWindow);
}
// Add a few settings for the webview
// The demo step is redundant since the values are the default settings
ICoreWebView2Settings* Settings;
webviewWindow->get_Settings(&Settings);
Settings->put_IsScriptEnabled(TRUE);
Settings->put_AreDefaultScriptDialogsEnabled(TRUE);
Settings->put_IsWebMessageEnabled(TRUE);
Settings->put_AreDevToolsEnabled(FALSE);
//Settings->put_AreDefaultContextMenusEnabled(FALSE);
Settings->put_IsStatusBarEnabled(FALSE);
// Resize WebView to fit the bounds of the parent window
RECT bounds;
GetClientRect(hWnd, &bounds);
webviewController->put_Bounds(bounds);
webviewController->put_ZoomFactor(0.8);
// Schedule an async task to navigate to Bing
webviewWindow->Navigate(HOME_PAGE);
// Step 4 - Navigation events
// Step 5 - Scripting
// Step 6 - Communication between host and web content
return S_OK;
}).Get());
return S_OK;
}).Get());
MSG msg;
BOOL bRet;
while ((bRet = GetMessage(
&msg,
NULL,
0,
0)) != 0)
{
// An error occured
if (bRet == -1)
{
break;
}
else
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
return (int)msg.wParam;
}
既然我现在偶然发现了这个问题，我真的很好奇是什么原因造成的。为什么它最终很重要？感谢您的指点。
无效表示网页没有显示。 window 为空白。 window.
上居然没有显示WebView2编辑：
wil::com_ptr实际上是什么？如果我改变这个：
static wil::com_ptr<ICoreWebView2Controller> webviewController;
static wil::com_ptr<ICoreWebView2> webviewWindow;
为此：
static ICoreWebView2Controller* webviewController;
static ICoreWebView2* webviewWindow;
在C++中，我打破了它。为什么？只是为什么？ （我用独立的 类 替换了回调 Microsoft::WRL::Callback，当然，它仍然有效，但是摆脱 COM 指针并使用常规指针会破坏它。为什么...？
解决方案很简单，如果真的花一分钟时间看一下代码的正确性和逻辑，而不是建议泛型和注释只是为了让跳线有一些字节可以携带。这部分必须稍微修改一下：因为我在函数 returns 之后使用 controller，并且没有使用智能指针，所以我必须增加它的引用计数，以便库知道我使用它而不是在 Invoke 函数体执行后释放它。当然，当你在使用智能指针的版本中进行赋值时，这是在后台自动完成的。不幸的是，我忽略了这一点，没有意识到会发生这种情况。像这样的事情是我用 C 编写这些端口的原因，这样我就可以深入了解并更好地理解这些东西从上到下是如何工作的。没有实际原因的“无法完成”对我来说不是一个有效的答案。
无论如何，这里是固定版本：
if (controller != NULL) {
webviewController = controller;
webviewController->lpVtbl->get_CoreWebView2(
webviewController,
&webviewWindow
);
webviewController->lpVtbl->AddRef(webviewController); // <-- here, increase the reference count for the webviewController
}
就是这样。非常感谢帮助我的人：https://github.com/MicrosoftEdge/WebView2Feedback/issues/1124