我有一个窗口(Windows),我的wndProc与Windows指南上的基本相同。但是,即使WM_CLOSE被传递(我可以使用 if(msg == WM_CLOSE)),我似乎也无法设置我的 shouldClose 标志。我已经确认我仍然在我的进程消息方法中获取事件。所以我的问题是:发生了什么,我怎样才能让它工作?
编辑:我尝试将窗口数据存储为结构而不是类,一切正常。即。我改变的只是类的类型,以及一些错误。
class Win32Window {
this(wstring title, int width, int height) {
immutable wstring className = "glass_def_class_name ";
auto hInstance = GetModuleHandle(null);
WNDCLASSW wc;
wc.lpfnWndProc = &windowProc;
wc.hInstance = hInstance;
wc.lpszClassName = &className[0];
RegisterClassW(&wc);
handle = CreateWindowExW(
0,
&className[0],
&title[0],
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT,
width, height,
null, null,
hInstance,
cast(void*) this);
ShowWindow(handle, SW_NORMAL);
}
~this() {
DestroyWindow(handle);
}
void processEvents() {
MSG msg;
while (PeekMessage(&msg, handle, 0, 0, PM_REMOVE)) {
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
bool shouldClose;
HWND handle;
private:
LRESULT processMessage(UINT msg, WPARAM wp, LPARAM lp) nothrow {
switch (msg) {
case WM_CLOSE:
shouldClose = true;
return 0;
default:
return DefWindowProc(handle, msg, wp, lp);
}
}
}
private extern (Windows) LRESULT windowProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp) nothrow {
Win32Window window;
if (msg == WM_CREATE) {
CREATESTRUCT* create = cast(CREATESTRUCT*) lp;
window = cast(Win32Window*) create.lpCreateParams;
SetWindowLongPtr(hwnd, GWLP_USERDATA, cast(LONG_PTR) create.lpCreateParams);
window.handle = hwnd;
}
else {
LONG_PTR ptr = GetWindowLongPtr(hwnd, GWLP_USERDATA);
window = cast(Win32Window* ptr);
}
if (window)
return window.processMessage(msg, wp, lp);
else
return DefWindowProc(hwnd, msg, wp, lp);
}
void main()
{
auto window = new Win32Window("test", 1280, 720);
while(window.shouldClose == false) {
window.processEvents();
}
window.destroy();
}
由方法修改的成员在退出后还原
这是当您使用对象的本地副本并对此本地副本进行修改时,但不是真正的对象。我没有看到其他解释
在windowProc
里面,你执行下一个Win32Window window = *(cast(Win32Window*) ptr);
- 所以你在windowProc
中制作初始对象状态的本地副本,然后对这个本地副本进行所有修改 - 当然,当你退出正确的代码时,它丢失windowProc
必须是下一个:
private LRESULT windowProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp) nothrow {
Win32Window* window;
if (msg == WM_NCCREATE) {
CREATESTRUCT* create = (CREATESTRUCT*) lp;
window = (Win32Window*) create.lpCreateParams;
SetWindowLongPtr(hwnd, GWLP_USERDATA, (LONG_PTR) create.lpCreateParams);
window.handle = hwnd;
}
else {
window = (Win32Window*)GetWindowLongPtr(hwnd, GWLP_USERDATA);
}
return window ? window->processMessage(msg, wp, lp) : DefWindowProc(hwnd, msg, wp, lp);
}
事实证明,您实际上无法将指针直接投射到引用。中介是必要的(或类似的东西)。因此,winProc
应如下所示:
private extern (Windows) LRESULT windowProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp) nothrow {
Win32Window window;
if (msg == WM_NCCREATE) {
auto create = cast(CREATESTRUCT*) lp;
window = cast(Win32Window) (cast(void*) create.lpCreateParams);
window.handle = hwnd;
SetWindowLongPtr(hwnd, GWLP_USERDATA, cast(LONG_PTR) create.lpCreateParams);
}
else {
window = cast(Win32Window) (cast(void*) GetWindowLongPtr(hwnd, GWLP_USERDATA));
}
return window ? window.processMessage(msg, wp, lp) : DefWindowProc(hwnd, msg, wp, lp);
}
请注意 create.lpCreateParams
和 GetWindowLongPtr(hwnd, GWLP_USERDATA)
之前的额外cast(void*)
。我不完全确定为什么这与我的原始代码相反有效,但它似乎有效,当我有时间时,我会做更多的调查。