c-关闭字体对话框时，窗口失去焦点

Question

#include <windows.h>
#include <tchar.h>
LRESULT CALLBACK SecondWndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch(msg)
{
case WM_RBUTTONUP:
{
HFONT hFont;
LOGFONT lf;
CHOOSEFONT cf = {0};
hFont = (HFONT)GetStockObject(DEFAULT_GUI_FONT);
GetObject(hFont, sizeof(LOGFONT), &lf);
cf.Flags = CF_INITTOLOGFONTSTRUCT | CF_SCREENFONTS;
cf.hwndOwner = hwnd;
cf.lpLogFont = &lf;
cf.lStructSize = sizeof(CHOOSEFONT);
if(ChooseFont(&cf))
{
}
}
break;
case WM_CLOSE:
DestroyWindow(hwnd);
break;
default:
return DefWindowProc(hwnd, msg, wParam, lParam);
}
return 0;
}
LRESULT CALLBACK FirstWndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch(msg)
{
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hwnd, msg, wParam, lParam);
}
return 0;
}
int WINAPI _tWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nShowCmd)
{
WNDCLASSEX wcFirst = {0}, wcSecond = {0};
HWND hwndFirst, hwndSecond;
MSG msg;
wcFirst.cbSize = sizeof(WNDCLASSEX);
wcFirst.hbrBackground = (HBRUSH)(COLOR_BTNFACE+1);
wcFirst.hCursor = LoadCursor(0, IDC_ARROW);
wcFirst.hIcon = LoadIcon(0, IDI_APPLICATION);
wcFirst.hInstance = hInstance;
wcFirst.lpfnWndProc = FirstWndProc;
wcFirst.lpszClassName = TEXT("FirstClass");

wcSecond.cbSize = sizeof(WNDCLASSEX);
wcSecond.hbrBackground = (HBRUSH)(COLOR_BTNFACE+1);
wcSecond.hCursor = LoadCursor(0, IDC_ARROW);
wcSecond.hIcon = LoadIcon(0, IDI_APPLICATION);
wcSecond.hInstance = hInstance;
wcSecond.lpfnWndProc = SecondWndProc;
wcSecond.lpszClassName = TEXT("SecondClass");

if(!RegisterClassEx(&wcFirst))
return 0;   
if(!RegisterClassEx(&wcSecond))
return 0;
hwndFirst = CreateWindowEx(0, TEXT("FirstClass"), TEXT("First Window"), WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT,
700, 400, 0, 0, hInstance, 0);
if(!hwndFirst)
return 0;
hwndSecond = CreateWindowEx(0, TEXT("SecondClass"), TEXT("Second Window"), WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT,
700, 400, hwndFirst, 0, hInstance, 0);
if(!hwndSecond)
return 0;

ShowWindow(hwndFirst, nShowCmd);
ShowWindow(hwndSecond, nShowCmd);
while(GetMessage(&msg, 0, 0, 0) > 0)
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return (int)msg.wParam;
}

在我关闭字体对话框和第二个窗口后，第一个窗口失去焦点并转到底部。顶部显示另一个应用程序的窗口。只有当我关闭字体对话框，然后关闭第二个窗口时才会发生这种情况。若只显示第一个窗口和第二个窗口，并且我关闭第二个窗，那个么第一个窗不会失去焦点。如果你想测试这个，在测试之前，请确保这个应用下面有另一个来自另一个应用的窗口。为什么第一个窗口会失去焦点？

Answer 1

您可以使用MessageBox重现相同的问题。任何时候禁用/启用第二个窗口(同时始终启用父窗口)并且关闭第二个窗时，第一个窗都可能无法正常恢复。WS_POPUP会解决这个问题。

当第二窗口最小化而第一窗口保持在顶部时，会出现另一个问题。您可以在第二个窗口中删除WS_MINIMIZEBOX来停止此操作。您也可以使用SetFocus(GetWindow(hwnd, GW_OWNER))重置焦点

LRESULT CALLBACK SecondWndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch (msg)
{
case WM_RBUTTONUP:
MessageBox(hwnd, TEXT("Test"), 0, 0);
break;
case WM_CLOSE:
SetFocus(GetWindow(hwnd, GW_OWNER));//force parent window to restore
DestroyWindow(hwnd);
break;
//...
hwndSecond = CreateWindowEx(WS_EX_CONTROLPARENT, TEXT("SecondClass"), TEXT("Second Window"),
WS_POPUP | WS_SYSMENU | WS_CAPTION | WS_THICKFRAME | WS_MAXIMIZEBOX,
CW_USEDEFAULT, CW_USEDEFAULT, 700, 400, hwndFirst, 0, hInstance, 0);