windows下的错误代码处理

た入场券 2022-06-18 04:48 197阅读 0赞

看了下《windows核心编程》的错误代码处理部分。我这才知道错误代码处理的重要性，以前的时候有错误就埋头苦调，现在发现当初好傻。埋头苦调根本就是又费力又费时，而且错误代码还不一定能调的出来。以后就用Windows下面的错误代码处理额···

下面是一个例子

#include <windows.h>
    
    
    DWORD GetLastErrorBox(HWND hWnd, LPSTR lpTitle);
    LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
    
    
    LPSTR szAppName = "Curves";
    LPSTR szTitle = "Curves Application";
    
    
    int WINAPI WinMain(
    				   HINSTANCE hInstance,
    				   HINSTANCE hPrevInstance,
    				   LPSTR lpCmdLine,
    				   int nCmdShow)
    {
    	MSG msg;
    	HWND hWnd;
    	WNDCLASS wc;
    	
    	// 注册窗口类
    	wc.style = CS_OWNDC; 
    	wc.lpfnWndProc = (WNDPROC)WndProc; 
    	wc.cbClsExtra = 0; 
    	wc.cbWndExtra = 0; 
    	wc.hInstance = hInstance;
    	wc.hIcon = NULL; 
    	wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    	wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
    	wc.lpszMenuName = NULL;
    	wc.lpszClassName = szAppName; 
    	
    	if (!RegisterClass(&wc))
    	{
    		GetLastErrorBox(NULL, "Error in RegisterClass");
    		return (FALSE);
    	}
    	// 创建窗口
    	hWnd = CreateWindow(
    		szAppName, 
    		szTitle, 
    		WS_OVERLAPPEDWINDOW,
    		CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, 
    		NULL, 
    		NULL,
    		hInstance, 
    		NULL 
    		);
    	
    	if (!hWnd)
    	{
    		GetLastErrorBox(hWnd, "Error in CreateWindow");
    		return (FALSE);
    	}
    	// 显示更新
    	ShowWindow(hWnd, nCmdShow); 
    	UpdateWindow(hWnd); 
    	// 消息循环
    	while (GetMessage(&msg, NULL, 0, 0))
    	{
    		TranslateMessage(&msg);
    		DispatchMessage(&msg);
    	}
    	
    	return (int)(msg.wParam);
    	
    	UNREFERENCED_PARAMETER(lpCmdLine); 
    }
    
    
    LRESULT CALLBACK WndProc(
    						 HWND hWnd, 
    						 UINT message, 
    						 WPARAM uParam, 
    						 LPARAM lParam)
    {
    	switch (message)
    	{
    	case WM_CREATE:
    		{
    			SetWindowLong(hWnd,GWL_EXSTYLE,NULL);//SetWindowLong(NULL,GWL_EXSTYLE,NULL);
    
    		}
    		GetLastErrorBox(hWnd, "Error in WM_CREATE");
    		break;
    
    
    	case WM_DESTROY: 
    
    
    		PostQuitMessage(0);
    		break;
    
    
    	default: 
    		return (DefWindowProc(hWnd, message, uParam, lParam));
    	}
    	return (0);
    }
    
    
    // 显示错误信息
    DWORD GetLastErrorBox(HWND hWnd, LPSTR lpTitle)
    {
    	LPVOID lpv;
    	DWORD dwRv;
    	
    	if (GetLastError() == 0) return 0;
    	
    	dwRv = FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
    		FORMAT_MESSAGE_FROM_SYSTEM,
    		NULL,
    		GetLastError(),
    		MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US),
    		(LPSTR)&lpv,
    		0,
    		NULL);
    	
    	MessageBox(hWnd, (LPCSTR)lpv, lpTitle, MB_OK);
    	
    	if(dwRv)
    		LocalFree(lpv);
    	
    	SetLastError(0);
    	return dwRv;
    }

在WM\_CREATE的时候若是我在函数SetWindowLong(hWnd,GWL\_EXSTYLE,NULL);第一个参数传入NULL，此时其实窗口还没生成，又何来句柄，然后就会出现错误消息，

我们自己写个函数把错误代码转化成我们能看得懂的东西。运行上面修改后的程序，就会弹出错误的框，内容是"Invalid window Handle"，这下就错误一目了然了额····

上面这个错误错里就当作模版处理，记在博客上面····