在 Windows 平台上的实现，相对比较顺利，将一个窗口嵌入到另外一个窗口是比较容易的事情。
1. 创建窗口
这里有点需要注意：
- 父窗口的大小变化时，子窗口也要跟着变化，否则 webview 显示不出来。
- 创建时窗口的大小先设置为 0，后面再调整，否则 webview 也显示不出来。
#include <windows.h>
#include <SDL_syswm.h>LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {switch (uMsg) {case WM_SIZE: {HWND hwndSub = FindWindowEx(hwnd, NULL, NULL, NULL);if (hwndSub) {RECT rcClient;int width = 0;int height = 0;GetClientRect(hwnd, &rcClient);width = rcClient.right - rcClient.left;height = rcClient.bottom - rcClient.top;MoveWindow(hwndSub, 0, 0, width, height, TRUE);}break;}case WM_PAINT: {PAINTSTRUCT ps;HDC hdc = BeginPaint(hwnd, &ps);FillRect(hdc, &ps.rcPaint, (HBRUSH)(COLOR_WINDOW + 1));EndPaint(hwnd, &ps);break;}default:return DefWindowProc(hwnd, uMsg, wParam, lParam);}return 0;
}static const char CLASS_NAME[] = "WebViewContainer";static ret_t webview_os_window_init(HINSTANCE hInstance) {WNDCLASSEX wc;ZeroMemory(&wc, sizeof(WNDCLASSEX));wc.cbSize = sizeof(WNDCLASSEX);wc.hInstance = hInstance;wc.lpszClassName = CLASS_NAME;wc.lpfnWndProc = WindowProc;RegisterClassEx(&wc);return RET_OK;
}webview_os_window_t webview_os_window_create(SDL_Window* parent, int x, int y, int w, int h) {SDL_SysWMinfo wmInfo;SDL_VERSION(&wmInfo.version);SDL_GetWindowWMInfo(parent, &wmInfo);HWND hwndParent = wmInfo.info.win.window;HINSTANCE hInstance = wmInfo.info.win.hinstance;webview_os_window_init(hInstance);HWND hwndSub = CreateWindowEx(0, CLASS_NAME, "Container Window", WS_CHILD | WS_VISIBLE, x, y, 0,0, hwndParent, NULL, hInstance, NULL);if (hwndSub == NULL) {return 0;}ShowWindow(hwndSub, SW_SHOW);UpdateWindow(hwndSub);if (!hwndSub) {printf("Failed to create subwindow: %lu\n", GetLastError());return NULL;}return (webview_os_window_t)hwndSub;
}2. 调整窗口大小
resize 窗口时，需要调整子窗口的大小。要注意的是，窗口的大小是以像素为单位的，所以需要考虑缩放因子。
void webview_os_window_move_resize(SDL_Window* parent, webview_os_window_t subwindow, int x, int y,int w, int h) {HWND hwndSub = (HWND)subwindow;float scale = system_info()->device_pixel_ratio;MoveWindow(hwndSub, x, y, w * scale, h * scale, TRUE);
}
3. 销毁窗口
销毁窗口时，需要销毁子窗口。
void webview_os_window_destroy(webview_os_window_t subwindow) {HWND hwndSub = (HWND)subwindow;DestroyWindow(hwndSub);
}