题
我最近让我的MainWindow使用WM_PAINT编写文本,但是现在我意识到这也许不是最好的消息,因此我尝试了另一个版本。
MainWindow包含一个菜单,在菜单项中,发送了ID_FILE_PID MSG,并构建了4个新的Windows Windows,同样是在MainWindow中显示文本(PaintEditSigns函数)。这4个窗口正常工作,但是文本dos根本不起作用,除非我在主()函数中进行此操作,如所示...这到底是什么? O_O
顺便说一句:我仍然不知道为什么在我发布时,stackoverflow上的代码播放保持如此糟糕,为什么?
switch(message)
{
case WM_COMMAND:
switch (LOWORD(wParam))
{
case ID_FILE_PID:
{
HWND hWndButton;
HWND hWndEdit;
HWND hWndEdit2;
HWND hWndDisplay;
// drawing the text in mainwindow
trigger=true;
// adding new windows in the mainwindow
hWndButton = CreateWindowEx(0,TEXT("BUTTON"),"Modify",WS_CHILD | WS_VISIBLE |
BS_DEFPUSHBUTTON, 170,56,80,30,hWnd,(HMENU)ID_BUTTON,hThisInstance,NULL);
hWndEdit = CreateWindowEx(0,RICHEDIT_CLASS,TEXT(""),WS_CHILD | WS_VISIBLE | WS_BORDER,
120,30,80,25,hWnd,(HMENU)ID_EDIT,hThisInstance,NULL);
hWndEdit2 = CreateWindowEx(0,RICHEDIT_CLASS,TEXT(""),WS_CHILD | WS_VISIBLE | WS_BORDER,
220,30,80,25,hWnd,(HMENU)ID_EDIT2,hThisInstance,NULL);
hWndDisplay = CreateWindowEx(0,TEXT("STATIC"),NULL,WS_CHILD | WS_VISIBLE | WS_BORDER,
0,100,450,140,hWnd,(HMENU)ID_DISPLAY,hThisInstance,NULL);
UpdateWindow(hWnd);
break;
}
.....
case WM_PAINT:
{
if (trigger) {
paintEditSigns()
}
break;
}
//
// Main function
//
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPSTR lpCmdLine, int nCmdShow)
{
HWND hWnd;
WNDCLASSEX wc;
ZeroMemory(&wc, sizeof(WNDCLASSEX));
hThisInstance = hInstance;
LoadLibrary("Riched20.dll");
wc.cbSize = sizeof(WNDCLASSEX);
wc.style = CS_HREDRAW | CS_VREDRAW;
wc.lpfnWndProc = WindowProc;
wc.hInstance = hInstance;
wc.lpszMenuName = MAKEINTRESOURCE(IDR_MYMENU);
if(!(wc.hIcon = LoadIcon(hInstance,MAKEINTRESOURCE(IDI_MYICON)))) {
HRESULT res = GetLastError();
}
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)COLOR_WINDOW;
wc.lpszClassName = TEXT("testcpp");
RegisterClassEx(&wc);
hWnd = CreateWindowEx(NULL,
wc.lpszClassName,
TEXT("test"),
WS_OVERLAPPEDWINDOW,
300,
200,
450,
300,
NULL,
NULL,
hInstance,
NULL);
ShowWindow(hWnd,nCmdShow);
//paintEditSigns() -- here it works, but not when in the message part
MSG msg;
while (GetMessage(&msg, NULL,0,0)) {
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return msg.wParam;
}
void paintEditSigns() {
HFONT hf = createFont();
PAINTSTRUCT ps;
HWND hWnd = FindWindow(TEXT("testcpp"),TEXT("test"));
HBRUSH hbruzh = CreateSolidBrush(RGB(0,0,0));
HDC hdz = BeginPaint(hWnd,&ps);
string s = "Memory Address";
SelectBrush(hdz,hbruzh);
SelectFont(hdz,hf);
TextOut(hdz,0,100,s.c_str(),s.length());
EndPaint(hWnd,&ps);
DeleteObject(hbruzh);
}
HFONT createFont() {
HDC hdc;
long lfHeight;
hdc = GetDC(NULL);
lfHeight = -MulDiv(12, GetDeviceCaps(hdc, LOGPIXELSY), 72);
ReleaseDC(NULL, hdc);
HFONT hf = CreateFont(lfHeight, 0, 0, 0, 0, TRUE, 0, 0, 0, 0, 0, 0, 0, "MS Sans Serif");
return hf;
}
解决方案
你可以 只要 利用 BeginPaint
/EndPaint
响应 WM_PAINT
. 。和 WM_PAINT
是这样的合适的地方。
Windows调用 WM_PAINT
当窗口的一部分被“无效”时。例如,如果您还原窗口,或者部分将窗口移开窗口或调整窗口大小后,窗口的一部分变得可见。
当您需要手动更新显示时,“无效”您需要通过调用需要重新绘制的区域 InvalidateRect
(这告诉窗户需要重新绘制的窗口区域)。
常见的是只是使整个窗口无效,而不是计算要绘制的区域的实际像素完美边界。
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