我如何计算 SCROLLINFO.nMax 到我的 window？
How do I calculate the SCROLLINFO.nMax to my window?
如何计算要设置到 SCROLLINFO.nMax 到我的 window 的值？目前我正在遍历 window 中的所有控件，跟踪最小 top 和最高 bottom 值，以便我可以获得整个 window 的大小]，包括那些在展示区之外，目前没有展示但仍然存在的。但是出了点问题，我在滚动条的末端得到了一个很大的空白区域，似乎 nMax 太大了。我错过了什么？一旦你完全向下滚动，它应该是 window 直到编辑框出现。现在的花言巧语：
我的尺码是这样的：
int scrollHeight(void)
{
int mTop = 0;
int mBottom = 0;
RECT rt = {0};
for(int i = 0; i < MAX_CONTROLS; i++)
{
HWND h = allControls[i];
if(h == NULL) break;
memset(&rt, 0, sizeof(RECT));
if(!GetWindowRect(h, &rt))
{
ErrorExit(NAMEOF(scrollHeight), __LINE__, __FILENAME__);
}
mBottom = my_max(mBottom, rt.bottom);
mTop = my_min(mTop, rt.top);
}
return mBottom - mTop;
}
像这样设置滚动条：
void setUpScrollBar(HWND hwnd)
{
RECT rc = { 0 };
GetClientRect(hwnd, &rc);
SCROLLINFO si = { 0 };
si.cbSize = sizeof(SCROLLINFO);
si.fMask = SIF_ALL;
si.nMin = 0;
si.nMax = scrollHeight();
si.nPage = (rc.bottom - rc.top);
si.nPos = 0;
si.nTrackPos = 0;
SetScrollInfo(hwnd, SB_VERT, &si, TRUE);
}
完整代码：
#pragma comment(lib, "user32.lib")
#pragma comment(lib, "Comctl32.lib")
#pragma comment(lib, "Gdi32.lib")
#define WIN32_LEAN_AND_MEAN
#define UNICODE
#define _UNICODE
#include <windows.h>
#include <Commctrl.h>
#include <crtdbg.h>
#include <strsafe.h>
#include <string.h>
#include <assert.h>
#ifdef UNICODE
#define STRSPLIT wcsrchr
#else
#define STRSPLIT strrchr
#endif
#define __FILENAME__ (STRSPLIT(TEXT(__FILE__), '/') ? STRSPLIT(TEXT(__FILE__), '/') + 1 : TEXT(__FILE__))
#define NAMEOF(s) TEXT(#s)
#define COUNTOF(a) (sizeof(a)/sizeof(a[0]))
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK CreateTabProc(HWND, UINT, WPARAM, LPARAM);
void ErrorExit(LPWSTR lpszFunction, int line, LPWSTR filename);
void InitComControls();
void ErrorExit(LPWSTR lpszFunction, int line, LPWSTR filename);
DWORD ShowLastError(LPWSTR lpszFunction, int line, LPWSTR filename);
void InitComControls();
void CreateTab(HWND hwnd);
void InsertTabItem(HWND tabHwnd, UINT id, LPWSTR text);
void CreateButtons(HWND hwnd);
RECT GetLocalCoordinates(HWND hWnd);
int scrollHeight(void);
int getHeight(HWND control);
void setUpScrollBar(HWND hwnd);
void pushControl(HWND);
inline int my_max(int a, int b);
inline int my_min(int a, int b);
void showText(HWND hwnd);
HINSTANCE ghInstance;
HWND hTab;
HWND hLabel1, hLabel2;
HWND hEdit1;
#define MAX_CONTROLS 8
static const wchar_t *title[] = { L"Button A1", L"Button B2", L"Button C3",
L"Button D4", L"Button E5", L"Button F6",
L"Button G" , L"Button 001", L"Button 002",
L"Button 003", L"Button 004",
L"Button 005", L"Button 006" };
HWND hButton[sizeof(title)/sizeof(title[0])] = {0};
HWND allControls[MAX_CONTROLS];
int allControls_indx = 0;
int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
PWSTR pCmdLine, int nCmdShow)
{
MSG msg = {0};
HWND hwnd;
WNDCLASSW wc = {0};
wc.lpszClassName = L"Window";
wc.hInstance = hInstance;
wc.hbrBackground = GetSysColorBrush(COLOR_3DFACE);
wc.lpfnWndProc = WndProc;
wc.hCursor = LoadCursor(0, IDC_ARROW);
InitComControls();
if(!RegisterClass(&wc)) {
ErrorExit(NAMEOF(RegisterClass), __LINE__, __FILENAME__);
}
int width = 500;
int height = 350/2; // half than the usual size, so that the scrollbar show up and we can test it
int screenWidth = GetSystemMetrics(SM_CXSCREEN);
int screenHeight = GetSystemMetrics(SM_CYSCREEN);
int cx = (screenWidth - width) / 2;
int cy = (screenHeight - height) / 2;
hwnd = CreateWindowW(wc.lpszClassName, L"Window",
WS_OVERLAPPEDWINDOW | WS_VISIBLE,
cx, cy, width, height, NULL, NULL,
hInstance, NULL);
pushControl(hwnd); // push main window too
ghInstance = hInstance;
while (GetMessage(&msg, NULL, 0, 0))
{
if (!IsDialogMessage(hwnd, &msg))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
return (int) msg.wParam;
}
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
static int g_scrollY;
switch(msg)
{
case WM_CREATE:
hLabel1 = CreateWindowW(L"Static", L"This is label 1...",
WS_VISIBLE | WS_CHILD | WS_TABSTOP,
50, 10, 130, 25, hwnd, (HMENU) 18, NULL, NULL);
pushControl(hLabel1);
hLabel2 = CreateWindowW(L"Static", L"This is label 2...",
WS_VISIBLE | WS_CHILD | WS_TABSTOP,
50, 40, 130, 25, hwnd, (HMENU) 19, NULL, NULL);
pushControl(hLabel2);
CreateTab(hwnd);
CreateButtons(hwnd);
setUpScrollBar(hwnd);
//ChangeToDefaultFont(hwnd);
break;
case WM_VSCROLL:
{
int action = LOWORD(wParam);
//HWND hScroll = (HWND)lParam;
int pos = -1;
if (action == SB_THUMBPOSITION || action == SB_THUMBTRACK) {
pos = HIWORD(wParam);
} else if (action == SB_LINEDOWN) {
pos = g_scrollY + 30;
} else if (action == SB_LINEUP) {
pos = g_scrollY - 30;
}
if (pos == -1)
break;
SCROLLINFO si = { 0 };
si.cbSize = sizeof(SCROLLINFO);
si.fMask = SIF_POS;
si.nPos = pos;
si.nTrackPos = 0;
SetScrollInfo(hwnd, SB_VERT, &si, TRUE);
GetScrollInfo(hwnd, SB_VERT, &si);
pos = si.nPos;
POINT pt;
pt.x = 0;
pt.y = pos - g_scrollY;
HDC hdc = GetDC(hwnd);
LPtoDP(hdc, &pt, 1);
ReleaseDC(hwnd, hdc);
ScrollWindow(hwnd, 0, -pt.y, NULL, NULL);
g_scrollY = pos;
return 0;
}
break;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
}
return DefWindowProc(hwnd, msg, wParam, lParam);
}
void pushControl(HWND hwnd)
{
if(allControls_indx > MAX_CONTROLS) {
assert(!"no room for extra controls");
}
allControls[allControls_indx++] = hwnd;
}
void CreateTab(HWND hwnd)
{
hTab =
CreateWindow(WC_TABCONTROLW, NULL,
WS_CHILD | WS_VISIBLE | WS_CLIPSIBLINGS | WS_TABSTOP,
100, 80, 400, 250,
hwnd,
(HMENU) 1,
NULL,
NULL);
InsertTabItem(hTab, 2, L"Tab 1");
InsertTabItem(hTab, 3, L"Tab b");
pushControl(hTab);
}
void CreateButtons(HWND hwnd)
{
RECT rt = GetLocalCoordinates(hTab);
TabCtrl_AdjustRect(hTab, FALSE, &rt);
RECT rt2 = {0};
GetWindowRect(hTab, &rt2);
int tab_width = rt2.right - rt2.left;
int tab_height = rt2.bottom - rt2.top;
int id = 4;
const int cy_breakSize = 25;
int cx_initPos = rt.left;
int cy_initPos = rt.top;
int cx = cx_initPos;
int cy = cy_initPos;
const int button_width = 80;
const int button_height = 25;
const int cx_margin = 10;
int nMaxButtonPerRow = tab_width / (button_width + cx_margin);
for(int i = 0; i < sizeof(title)/sizeof(title[0]); ++i)
{
if(i != 0 && (i % nMaxButtonPerRow) == 0) {
cy += cy_breakSize;
cx = cx_initPos;
}
hButton[i] =
CreateWindow(L"button", title[i],
WS_VISIBLE | WS_CHILD | WS_TABSTOP | ES_AUTOHSCROLL,
cx,
cy,
button_width,
button_height,
hwnd, (HMENU) id++, NULL, NULL);
cx += button_width;
}
const int edit_width = 180;
const int edit_height = 25;
hEdit1 = CreateWindow(L"Edit", L"Hello, world!",
WS_VISIBLE | WS_CHILD | WS_BORDER,
cx,
// put below tab control's display area
getHeight(hTab) + cx,
edit_width,
edit_height,
hwnd,
(HMENU) id++,
NULL, NULL);
pushControl(hEdit1);
cx += edit_width;
}
void setUpScrollBar(HWND hwnd)
{
RECT rc = { 0 };
GetClientRect(hwnd, &rc);
SCROLLINFO si = { 0 };
si.cbSize = sizeof(SCROLLINFO);
si.fMask = SIF_ALL;
si.nMin = 0;
si.nMax = scrollHeight();
si.nPage = (rc.bottom - rc.top);
si.nPos = 0;
si.nTrackPos = 0;
SetScrollInfo(hwnd, SB_VERT, &si, TRUE);
}
int getHeight(HWND control)
{
RECT rt;
if(!GetWindowRect(control, &rt)) {
ErrorExit(NAMEOF(getHeight), __LINE__, __FILENAME__);
}
return rt.bottom - rt.top;
}
int scrollHeight(void)
{
int mTop = 0;
int mBottom = 0;
RECT rt = {0};
for(int i = 0; i < MAX_CONTROLS; i++)
{
HWND h = allControls[i];
if(h == NULL) break;
memset(&rt, 0, sizeof(RECT));
if(!GetWindowRect(h, &rt))
{
ErrorExit(NAMEOF(scrollHeight), __LINE__, __FILENAME__);
}
mBottom = my_max(mBottom, rt.bottom);
mTop = my_min(mTop, rt.top);
}
return mBottom - mTop;
}
inline int my_max(int a, int b)
{
return a > b ? a : b;
}
inline int my_min(int a, int b)
{
return a < b ? a : b;
}
RECT GetLocalCoordinates(HWND hWnd)
{
RECT Rect;
GetWindowRect(hWnd, &Rect);
MapWindowPoints(HWND_DESKTOP, GetParent(hWnd), (LPPOINT) &Rect, 2);
return Rect;
}
void InsertTabItem(HWND tabHwnd, UINT id, LPWSTR text)
{
TCITEMW tci = {0};
tci.mask = TCIF_TEXT;
tci.pszText = text;
tci.cchTextMax = lstrlenW(text);
SendMessage(tabHwnd, TCM_INSERTITEM, id, (LPARAM) &tci);
}
void InitComControls()
{
INITCOMMONCONTROLSEX icex;
/* initialize this component is required to use tab control,
it seems.
*/
icex.dwSize = sizeof(INITCOMMONCONTROLSEX);
icex.dwICC = ICC_TAB_CLASSES;
InitCommonControlsEx(&icex);
}
// display the error message from last error seen then
// exit the application, with that last error code seen.
// to test function, do something like:
// if(!GetProcessId(NULL))
// errorExit(TEXT("GetProcessId"));
// not quite a unittest but yeah.
void ErrorExit(LPWSTR lpszFunction, int line, LPWSTR filename)
{
DWORD dw = ShowLastError(lpszFunction, line, filename);
ExitProcess(dw);
}
DWORD ShowLastError(LPWSTR lpszFunction, int line, LPWSTR filename)
{
#define MAX_DIGITS 16
/*
* NOTE!!: calling GetLastError() must be done before calling
* any other function, that would reset the GetLastError(), making
* this function report error about the wrong function.
*/
DWORD dw = GetLastError();
LPVOID lpMsgBuf;
LPVOID lpDisplayBuf;
FormatMessage(
FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS,
NULL,
dw,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPTSTR) &lpMsgBuf,
0,
NULL
);
lpDisplayBuf = (LPVOID) LocalAlloc(LMEM_ZEROINIT,
(lstrlen((LPCTSTR)lpMsgBuf) +
lstrlen((LPCTSTR)lpszFunction) + 40 +
(line > 0 ? MAX_DIGITS : 0) +
(filename != NULL ? lstrlen(filename) : 0)) *
sizeof(TCHAR)
);
StringCchPrintf((LPTSTR)lpDisplayBuf,
LocalSize(lpDisplayBuf) / sizeof(TCHAR),
TEXT("%s failed with %d: %s"),
lpszFunction, dw, lpMsgBuf
);
MessageBox(NULL, (LPCTSTR)lpDisplayBuf, TEXT("Error"), MB_OK);
LocalFree(lpMsgBuf);
LocalFree(lpDisplayBuf);
return dw;
}
您的 scrollHeight() 函数中的这一行是问题所在：
mTop = my_min(mTop, rt.top);
mTop 开始时为 0，因此始终是最小值。你最终得到的不是顶部和底部控件之间的距离，而是屏幕顶部到底部控件底部的距离（请注意，因为你使用的是 GetWindowRect，所以你处理的是屏幕坐标，而不是客户坐标 - 所以这会放大问题）。
如果将该行更改为以下内容，结果会更好：
mTop = mTop ? my_min(mTop, rt.top) : rt.top;
如何计算要设置到 SCROLLINFO.nMax 到我的 window 的值？目前我正在遍历 window 中的所有控件，跟踪最小 top 和最高 bottom 值，以便我可以获得整个 window 的大小]，包括那些在展示区之外，目前没有展示但仍然存在的。但是出了点问题，我在滚动条的末端得到了一个很大的空白区域，似乎 nMax 太大了。我错过了什么？一旦你完全向下滚动，它应该是 window 直到编辑框出现。现在的花言巧语：
我的尺码是这样的：
int scrollHeight(void)
{
int mTop = 0;
int mBottom = 0;
RECT rt = {0};
for(int i = 0; i < MAX_CONTROLS; i++)
{
HWND h = allControls[i];
if(h == NULL) break;
memset(&rt, 0, sizeof(RECT));
if(!GetWindowRect(h, &rt))
{
ErrorExit(NAMEOF(scrollHeight), __LINE__, __FILENAME__);
}
mBottom = my_max(mBottom, rt.bottom);
mTop = my_min(mTop, rt.top);
}
return mBottom - mTop;
}
像这样设置滚动条：
void setUpScrollBar(HWND hwnd)
{
RECT rc = { 0 };
GetClientRect(hwnd, &rc);
SCROLLINFO si = { 0 };
si.cbSize = sizeof(SCROLLINFO);
si.fMask = SIF_ALL;
si.nMin = 0;
si.nMax = scrollHeight();
si.nPage = (rc.bottom - rc.top);
si.nPos = 0;
si.nTrackPos = 0;
SetScrollInfo(hwnd, SB_VERT, &si, TRUE);
}
完整代码：
#pragma comment(lib, "user32.lib")
#pragma comment(lib, "Comctl32.lib")
#pragma comment(lib, "Gdi32.lib")
#define WIN32_LEAN_AND_MEAN
#define UNICODE
#define _UNICODE
#include <windows.h>
#include <Commctrl.h>
#include <crtdbg.h>
#include <strsafe.h>
#include <string.h>
#include <assert.h>
#ifdef UNICODE
#define STRSPLIT wcsrchr
#else
#define STRSPLIT strrchr
#endif
#define __FILENAME__ (STRSPLIT(TEXT(__FILE__), '/') ? STRSPLIT(TEXT(__FILE__), '/') + 1 : TEXT(__FILE__))
#define NAMEOF(s) TEXT(#s)
#define COUNTOF(a) (sizeof(a)/sizeof(a[0]))
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK CreateTabProc(HWND, UINT, WPARAM, LPARAM);
void ErrorExit(LPWSTR lpszFunction, int line, LPWSTR filename);
void InitComControls();
void ErrorExit(LPWSTR lpszFunction, int line, LPWSTR filename);
DWORD ShowLastError(LPWSTR lpszFunction, int line, LPWSTR filename);
void InitComControls();
void CreateTab(HWND hwnd);
void InsertTabItem(HWND tabHwnd, UINT id, LPWSTR text);
void CreateButtons(HWND hwnd);
RECT GetLocalCoordinates(HWND hWnd);
int scrollHeight(void);
int getHeight(HWND control);
void setUpScrollBar(HWND hwnd);
void pushControl(HWND);
inline int my_max(int a, int b);
inline int my_min(int a, int b);
void showText(HWND hwnd);
HINSTANCE ghInstance;
HWND hTab;
HWND hLabel1, hLabel2;
HWND hEdit1;
#define MAX_CONTROLS 8
static const wchar_t *title[] = { L"Button A1", L"Button B2", L"Button C3",
L"Button D4", L"Button E5", L"Button F6",
L"Button G" , L"Button 001", L"Button 002",
L"Button 003", L"Button 004",
L"Button 005", L"Button 006" };
HWND hButton[sizeof(title)/sizeof(title[0])] = {0};
HWND allControls[MAX_CONTROLS];
int allControls_indx = 0;
int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
PWSTR pCmdLine, int nCmdShow)
{
MSG msg = {0};
HWND hwnd;
WNDCLASSW wc = {0};
wc.lpszClassName = L"Window";
wc.hInstance = hInstance;
wc.hbrBackground = GetSysColorBrush(COLOR_3DFACE);
wc.lpfnWndProc = WndProc;
wc.hCursor = LoadCursor(0, IDC_ARROW);
InitComControls();
if(!RegisterClass(&wc)) {
ErrorExit(NAMEOF(RegisterClass), __LINE__, __FILENAME__);
}
int width = 500;
int height = 350/2; // half than the usual size, so that the scrollbar show up and we can test it
int screenWidth = GetSystemMetrics(SM_CXSCREEN);
int screenHeight = GetSystemMetrics(SM_CYSCREEN);
int cx = (screenWidth - width) / 2;
int cy = (screenHeight - height) / 2;
hwnd = CreateWindowW(wc.lpszClassName, L"Window",
WS_OVERLAPPEDWINDOW | WS_VISIBLE,
cx, cy, width, height, NULL, NULL,
hInstance, NULL);
pushControl(hwnd); // push main window too
ghInstance = hInstance;
while (GetMessage(&msg, NULL, 0, 0))
{
if (!IsDialogMessage(hwnd, &msg))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
return (int) msg.wParam;
}
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
static int g_scrollY;
switch(msg)
{
case WM_CREATE:
hLabel1 = CreateWindowW(L"Static", L"This is label 1...",
WS_VISIBLE | WS_CHILD | WS_TABSTOP,
50, 10, 130, 25, hwnd, (HMENU) 18, NULL, NULL);
pushControl(hLabel1);
hLabel2 = CreateWindowW(L"Static", L"This is label 2...",
WS_VISIBLE | WS_CHILD | WS_TABSTOP,
50, 40, 130, 25, hwnd, (HMENU) 19, NULL, NULL);
pushControl(hLabel2);
CreateTab(hwnd);
CreateButtons(hwnd);
setUpScrollBar(hwnd);
//ChangeToDefaultFont(hwnd);
break;
case WM_VSCROLL:
{
int action = LOWORD(wParam);
//HWND hScroll = (HWND)lParam;
int pos = -1;
if (action == SB_THUMBPOSITION || action == SB_THUMBTRACK) {
pos = HIWORD(wParam);
} else if (action == SB_LINEDOWN) {
pos = g_scrollY + 30;
} else if (action == SB_LINEUP) {
pos = g_scrollY - 30;
}
if (pos == -1)
break;
SCROLLINFO si = { 0 };
si.cbSize = sizeof(SCROLLINFO);
si.fMask = SIF_POS;
si.nPos = pos;
si.nTrackPos = 0;
SetScrollInfo(hwnd, SB_VERT, &si, TRUE);
GetScrollInfo(hwnd, SB_VERT, &si);
pos = si.nPos;
POINT pt;
pt.x = 0;
pt.y = pos - g_scrollY;
HDC hdc = GetDC(hwnd);
LPtoDP(hdc, &pt, 1);
ReleaseDC(hwnd, hdc);
ScrollWindow(hwnd, 0, -pt.y, NULL, NULL);
g_scrollY = pos;
return 0;
}
break;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
}
return DefWindowProc(hwnd, msg, wParam, lParam);
}
void pushControl(HWND hwnd)
{
if(allControls_indx > MAX_CONTROLS) {
assert(!"no room for extra controls");
}
allControls[allControls_indx++] = hwnd;
}
void CreateTab(HWND hwnd)
{
hTab =
CreateWindow(WC_TABCONTROLW, NULL,
WS_CHILD | WS_VISIBLE | WS_CLIPSIBLINGS | WS_TABSTOP,
100, 80, 400, 250,
hwnd,
(HMENU) 1,
NULL,
NULL);
InsertTabItem(hTab, 2, L"Tab 1");
InsertTabItem(hTab, 3, L"Tab b");
pushControl(hTab);
}
void CreateButtons(HWND hwnd)
{
RECT rt = GetLocalCoordinates(hTab);
TabCtrl_AdjustRect(hTab, FALSE, &rt);
RECT rt2 = {0};
GetWindowRect(hTab, &rt2);
int tab_width = rt2.right - rt2.left;
int tab_height = rt2.bottom - rt2.top;
int id = 4;
const int cy_breakSize = 25;
int cx_initPos = rt.left;
int cy_initPos = rt.top;
int cx = cx_initPos;
int cy = cy_initPos;
const int button_width = 80;
const int button_height = 25;
const int cx_margin = 10;
int nMaxButtonPerRow = tab_width / (button_width + cx_margin);
for(int i = 0; i < sizeof(title)/sizeof(title[0]); ++i)
{
if(i != 0 && (i % nMaxButtonPerRow) == 0) {
cy += cy_breakSize;
cx = cx_initPos;
}
hButton[i] =
CreateWindow(L"button", title[i],
WS_VISIBLE | WS_CHILD | WS_TABSTOP | ES_AUTOHSCROLL,
cx,
cy,
button_width,
button_height,
hwnd, (HMENU) id++, NULL, NULL);
cx += button_width;
}
const int edit_width = 180;
const int edit_height = 25;
hEdit1 = CreateWindow(L"Edit", L"Hello, world!",
WS_VISIBLE | WS_CHILD | WS_BORDER,
cx,
// put below tab control's display area
getHeight(hTab) + cx,
edit_width,
edit_height,
hwnd,
(HMENU) id++,
NULL, NULL);
pushControl(hEdit1);
cx += edit_width;
}
void setUpScrollBar(HWND hwnd)
{
RECT rc = { 0 };
GetClientRect(hwnd, &rc);
SCROLLINFO si = { 0 };
si.cbSize = sizeof(SCROLLINFO);
si.fMask = SIF_ALL;
si.nMin = 0;
si.nMax = scrollHeight();
si.nPage = (rc.bottom - rc.top);
si.nPos = 0;
si.nTrackPos = 0;
SetScrollInfo(hwnd, SB_VERT, &si, TRUE);
}
int getHeight(HWND control)
{
RECT rt;
if(!GetWindowRect(control, &rt)) {
ErrorExit(NAMEOF(getHeight), __LINE__, __FILENAME__);
}
return rt.bottom - rt.top;
}
int scrollHeight(void)
{
int mTop = 0;
int mBottom = 0;
RECT rt = {0};
for(int i = 0; i < MAX_CONTROLS; i++)
{
HWND h = allControls[i];
if(h == NULL) break;
memset(&rt, 0, sizeof(RECT));
if(!GetWindowRect(h, &rt))
{
ErrorExit(NAMEOF(scrollHeight), __LINE__, __FILENAME__);
}
mBottom = my_max(mBottom, rt.bottom);
mTop = my_min(mTop, rt.top);
}
return mBottom - mTop;
}
inline int my_max(int a, int b)
{
return a > b ? a : b;
}
inline int my_min(int a, int b)
{
return a < b ? a : b;
}
RECT GetLocalCoordinates(HWND hWnd)
{
RECT Rect;
GetWindowRect(hWnd, &Rect);
MapWindowPoints(HWND_DESKTOP, GetParent(hWnd), (LPPOINT) &Rect, 2);
return Rect;
}
void InsertTabItem(HWND tabHwnd, UINT id, LPWSTR text)
{
TCITEMW tci = {0};
tci.mask = TCIF_TEXT;
tci.pszText = text;
tci.cchTextMax = lstrlenW(text);
SendMessage(tabHwnd, TCM_INSERTITEM, id, (LPARAM) &tci);
}
void InitComControls()
{
INITCOMMONCONTROLSEX icex;
/* initialize this component is required to use tab control,
it seems.
*/
icex.dwSize = sizeof(INITCOMMONCONTROLSEX);
icex.dwICC = ICC_TAB_CLASSES;
InitCommonControlsEx(&icex);
}
// display the error message from last error seen then
// exit the application, with that last error code seen.
// to test function, do something like:
// if(!GetProcessId(NULL))
// errorExit(TEXT("GetProcessId"));
// not quite a unittest but yeah.
void ErrorExit(LPWSTR lpszFunction, int line, LPWSTR filename)
{
DWORD dw = ShowLastError(lpszFunction, line, filename);
ExitProcess(dw);
}
DWORD ShowLastError(LPWSTR lpszFunction, int line, LPWSTR filename)
{
#define MAX_DIGITS 16
/*
* NOTE!!: calling GetLastError() must be done before calling
* any other function, that would reset the GetLastError(), making
* this function report error about the wrong function.
*/
DWORD dw = GetLastError();
LPVOID lpMsgBuf;
LPVOID lpDisplayBuf;
FormatMessage(
FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS,
NULL,
dw,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPTSTR) &lpMsgBuf,
0,
NULL
);
lpDisplayBuf = (LPVOID) LocalAlloc(LMEM_ZEROINIT,
(lstrlen((LPCTSTR)lpMsgBuf) +
lstrlen((LPCTSTR)lpszFunction) + 40 +
(line > 0 ? MAX_DIGITS : 0) +
(filename != NULL ? lstrlen(filename) : 0)) *
sizeof(TCHAR)
);
StringCchPrintf((LPTSTR)lpDisplayBuf,
LocalSize(lpDisplayBuf) / sizeof(TCHAR),
TEXT("%s failed with %d: %s"),
lpszFunction, dw, lpMsgBuf
);
MessageBox(NULL, (LPCTSTR)lpDisplayBuf, TEXT("Error"), MB_OK);
LocalFree(lpMsgBuf);
LocalFree(lpDisplayBuf);
return dw;
}
您的 scrollHeight() 函数中的这一行是问题所在：
mTop = my_min(mTop, rt.top);
mTop 开始时为 0，因此始终是最小值。你最终得到的不是顶部和底部控件之间的距离，而是屏幕顶部到底部控件底部的距离（请注意，因为你使用的是 GetWindowRect，所以你处理的是屏幕坐标，而不是客户坐标 - 所以这会放大问题）。
如果将该行更改为以下内容，结果会更好：
mTop = mTop ? my_min(mTop, rt.top) : rt.top;