Windows界面编程第四篇 异形窗体 高富帅版

 上一篇《Windows界面编程第三篇 异形窗体 普通版》介绍了异形窗口（异形窗体）的创建，其主要步骤为——先通过创建位图画刷来做窗口的背景画刷，再通过SetWindowLong为窗体加上WS_EX_LAYERED属性，然后使用SetLayeredWindowAttributes指定窗口的透明色来完成窗口形状的调整。并且为了使异形窗口支持鼠标的拖曳，在WM_LBUTTONDOWN消息中作了特殊处理。

然后在下图中有非常相似的两个异形窗体，只不过，左边的异形窗体小，右边的异形窗体大。这个可以怎么实现了？

先通过其它软件来缩放位图，然后再让程序加载这种方式来指定异形窗口的大小。这种方法虽然可以完成任务，但毕竟太OUT了。

由《Windows界面编程第一篇位图背景与位图画刷》可以想到不用位图画刷，而直接在窗口背景绘制时使用StretchBlt来缩放位图至窗口大小，这样就可以达到指定窗口大小的功能。

由于异形窗口运行后无法通过鼠标来动态调整窗口大小，因此可以窗口初始化时就可以先缩放位图并加载到一个缓冲HDC中，然后再在窗口背景绘制时使用BitBlt来贴图。这种做法只需要缩放位图一次，在每次背景绘制时只须拷贝位图，对程序的效率会有提高。下面给出完整源代码（下载地址：http://download.csdn.net/download/morewindows/4966819）

//   异形窗口2  在WM_ERASEBKGND消息中自贴图
//By MoreWindows-(http://blog.csdn.net/MoreWindows)
#include <windows.h>
constchar szAppName[] ="异形窗口2 MoreWindows-(http://blog.csdn.net/MoreWindows)";

/*
* 函数名称: GetWindowSize
* 函数功能: 得到窗口的宽高
* hwnd      窗口句柄
* pnWidth   窗口宽
* pnHeight  窗口高
*/
void GetWindowSize(HWND hwnd,int *pnWidth,int
 *pnHeight);


/*
* 函数名称: InitBitmapWindow
* 函数功能: 位图窗口初始化
* hinstance 进程实例
* nWidth    窗口宽
* nHeight   窗口高
* nCmdshow  显示方式-与ShowWindow函数的第二个参数相同
*/
BOOL InitBitmapWindow(HINSTANCE hinstance,int nWidth,int
 nHeight,int nCmdshow);

// 位图窗口消息处理函数
LRESULT CALLBACK BitmapWindowWndPrco(HWND hwnd,UINT message,WPARAM
 wParam,LPARAM lParm);


HBITMAP  g_hBitmap;
int APIENTRY WinMain(HINSTANCE hInstance,
                     
HINSTANCE hPrevInstance,
                    LPSTR     lpCmdLine,
                     
int       nCmdShow)
{
    //先创建一个无背影画刷窗口，
    
//然后在WM_CREATE中并指定透明颜色, 缩放位图后加载至s_hdcMem中.
    //最后在WM_ERASEBKGND中用s_hdcMem贴图即可
    g_hBitmap = (HBITMAP)LoadImage(NULL,"Kitty.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
    if (g_hBitmap == NULL)
    {
        MessageBox(NULL, 
"位图加载失败", "Error", MB_ICONERROR);
        
return 0;
    }

    // 设置异形窗口大小
    BITMAP bm;
    GetObject(g_hBitmap, 
sizeof(bm), &bm);
    
int nWindowWidth = bm.bmWidth;
    int nWindowHeight = bm.bmHeight + 100;//拉高100高度

    if (!InitBitmapWindow(hInstance, nWindowWidth, nWindowHeight, nCmdShow))
        
return 0;

    MSG msg;
    while (GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    DeleteObject(g_hBitmap);

    
return msg.wParam;
}


BOOL InitBitmapWindow(HINSTANCE hinstance,int nWidth,int
 nHeight,int nCmdshow)
{
    
HWND hwnd;
    WNDCLASS wndclass;

    wndclass.style       = CS_VREDRAW | CS_HREDRAW;
    wndclass.lpfnWndProc = BitmapWindowWndPrco;
    wndclass.cbClsExtra  = 0;
    wndclass.cbWndExtra  = 0;
    wndclass.hInstance   = hinstance;
    wndclass.hIcon       = LoadIcon(NULL, IDI_APPLICATION);
    wndclass.hCursor     = LoadCursor(NULL, IDC_ARROW);
    wndclass.hbrBackground = (HBRUSH)GetStockObject(NULL_BRUSH);//窗口背影画刷为空
    wndclass.lpszMenuName  = NULL;
    wndclass.lpszClassName = szAppName;

    
if (!RegisterClass(&wndclass))
    {
        MessageBox(NULL,"Program Need Windows NT!","Error", MB_ICONERROR);
        
return FALSE;
    }

    hwnd = CreateWindowEx(WS_EX_TOPMOST,
                        szAppName,
                        szAppName,
                        WS_POPUP,
                        CW_USEDEFAULT,
                        CW_USEDEFAULT,
                        nWidth,
                        nHeight,
                        NULL,
                        NULL,
                        hinstance,
                        NULL);
    
if (hwnd == NULL)
        
return FALSE;

    ShowWindow(hwnd, nCmdshow);
    UpdateWindow(hwnd);

    
return TRUE;
}

LRESULT CALLBACK BitmapWindowWndPrco(HWND hwnd,UINT message,WPARAM
 wParam,LPARAM lParm)
{
    staticHDC s_hdcMem;//放置缩放后的位图

    switch (message)
    {
    case WM_CREATE:
        {
            
// 设置分层属性
            SetWindowLong(hwnd, GWL_EXSTYLE, GetWindowLong(hwnd, GWL_EXSTYLE) | WS_EX_LAYERED);
            
// 设置透明色
            
COLORREF clTransparent = RGB(0, 0, 0);
            SetLayeredWindowAttributes(hwnd, clTransparent, 0, LWA_COLORKEY);

            
//   缩放位图
            
// 加载位图到hdcTemp中
            
HDC hdc = GetDC(hwnd);
            
HDC hdcTemp = CreateCompatibleDC(hdc);
            SelectObject(hdcTemp, g_hBitmap);

            
// 得到窗口大小
            
int nWidth, nHeight;
            GetWindowSize(hwnd, &nWidth, &nHeight);

            
// 创建与窗口大小相等且能容纳位图的HDC - s_hdcMem
            s_hdcMem = CreateCompatibleDC(hdc);
            
HBITMAP hbmp = CreateCompatibleBitmap(hdc, nWidth, nHeight);
            SelectObject(s_hdcMem, hbmp);

            
// 将原位图缩放到窗口大小
            BITMAP bm;
            GetObject(g_hBitmap,sizeof(bm), &bm);
            StretchBlt(s_hdcMem, 0, 0, nWidth, nHeight, hdcTemp, 0, 0, bm.bmWidth, bm.bmHeight, SRCCOPY);

            
// 释放资源
            DeleteDC(hdcTemp);
            ReleaseDC(hwnd, hdc);
        }
        
return 0;


    
case WM_KEYDOWN:
        
switch (wParam)
        {
        
case VK_ESCAPE: //按下Esc键时退出
            SendMessage(hwnd, WM_DESTROY, 0, 0);
            
return TRUE;
        }
        
break;


    
case WM_LBUTTONDOWN: //当鼠标左键点击时可以拖曳窗口
        PostMessage(hwnd, WM_SYSCOMMAND, SC_MOVE | HTCAPTION, 0);
        
return TRUE;

    
case WM_ERASEBKGND: //在窗口背景中直接贴图
        {
            
HDC hdc = (HDC)wParam;
            
int nWidth, nHeight;
            GetWindowSize(hwnd, &nWidth, &nHeight);
            BitBlt(hdc, 0, 0, nWidth, nHeight, s_hdcMem, 0, 0, SRCCOPY);
            
return TRUE;
        }

    case WM_DESTROY:
        DeleteDC(s_hdcMem);
        PostQuitMessage(0);
        
return 0;
    }
    
return DefWindowProc(hwnd, message, wParam, lParm);
}


void GetWindowSize(HWND hwnd,int *pnWidth,int
 *pnHeight)
{
    RECT rc;
    GetWindowRect(hwnd, &rc);
    *pnWidth = rc.right - rc.left;
    *pnHeight = rc.bottom - rc.top;
}

//   异形窗口2  在WM_ERASEBKGND消息中自贴图
//By MoreWindows-(http://blog.csdn.net/MoreWindows)
#include <windows.h>
const char szAppName[] = "异形窗口2 MoreWindows-(http://blog.csdn.net/MoreWindows)";

/*
 * 函数名称: GetWindowSize
 * 函数功能: 得到窗口的宽高
 * hwnd      窗口句柄
 * pnWidth   窗口宽
 * pnHeight  窗口高
*/
void GetWindowSize(HWND hwnd, int *pnWidth, int *pnHeight);


/*
 * 函数名称: InitBitmapWindow
 * 函数功能: 位图窗口初始化
 * hinstance 进程实例
 * nWidth    窗口宽
 * nHeight   窗口高
 * nCmdshow  显示方式-与ShowWindow函数的第二个参数相同
*/
BOOL InitBitmapWindow(HINSTANCE hinstance, int nWidth, int nHeight, int nCmdshow);

// 位图窗口消息处理函数
LRESULT CALLBACK BitmapWindowWndPrco(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParm);

          
HBITMAP  g_hBitmap;
int APIENTRY WinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,
                     int       nCmdShow)
{
    //先创建一个无背影画刷窗口，
	//然后在WM_CREATE中并指定透明颜色, 缩放位图后加载至s_hdcMem中.
	//最后在WM_ERASEBKGND中用s_hdcMem贴图即可
	g_hBitmap = (HBITMAP)LoadImage(NULL, "Kitty.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
	if (g_hBitmap == NULL)
	{
		MessageBox(NULL, "位图加载失败", "Error", MB_ICONERROR);
		return 0;
	}

	// 设置异形窗口大小
	BITMAP bm;
	GetObject(g_hBitmap, sizeof(bm), &bm);
	int nWindowWidth = bm.bmWidth;
	int nWindowHeight = bm.bmHeight + 100; //拉高100高度

	if (!InitBitmapWindow(hInstance, nWindowWidth, nWindowHeight, nCmdShow))
		return 0;

	MSG msg;
	while (GetMessage(&msg, NULL, 0, 0))
	{
		TranslateMessage(&msg);
		DispatchMessage(&msg);
	}
	DeleteObject(g_hBitmap);

	return msg.wParam;
}


BOOL InitBitmapWindow(HINSTANCE hinstance, int nWidth, int nHeight, int nCmdshow)
{
	HWND hwnd;
	WNDCLASS wndclass;
	
	wndclass.style       = CS_VREDRAW | CS_HREDRAW;
	wndclass.lpfnWndProc = BitmapWindowWndPrco;	
	wndclass.cbClsExtra  = 0;
	wndclass.cbWndExtra  = 0;
	wndclass.hInstance   = hinstance;	
	wndclass.hIcon       = LoadIcon(NULL, IDI_APPLICATION);
	wndclass.hCursor     = LoadCursor(NULL, IDC_ARROW);
	wndclass.hbrBackground = (HBRUSH)GetStockObject(NULL_BRUSH);//窗口背影画刷为空
	wndclass.lpszMenuName  = NULL;
	wndclass.lpszClassName = szAppName;
	
	if (!RegisterClass(&wndclass))
	{
		MessageBox(NULL, "Program Need Windows NT!", "Error", MB_ICONERROR);
		return FALSE;
	}
	
	hwnd = CreateWindowEx(WS_EX_TOPMOST,
						szAppName,
						szAppName, 
						WS_POPUP,
						CW_USEDEFAULT, 
						CW_USEDEFAULT, 
						nWidth, 
						nHeight,
						NULL,
						NULL,
						hinstance,
						NULL);
	if (hwnd == NULL)
		return FALSE;
	
	ShowWindow(hwnd, nCmdshow);
	UpdateWindow(hwnd);
	
	return TRUE;
}

LRESULT CALLBACK BitmapWindowWndPrco(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParm)
{
	static HDC s_hdcMem; //放置缩放后的位图
	
	switch (message)
	{
	case WM_CREATE:
		{
			// 设置分层属性
 			SetWindowLong(hwnd, GWL_EXSTYLE, GetWindowLong(hwnd, GWL_EXSTYLE) | WS_EX_LAYERED);
			// 设置透明色
			COLORREF clTransparent = RGB(0, 0, 0);
 			SetLayeredWindowAttributes(hwnd, clTransparent, 0, LWA_COLORKEY);
			
			//   缩放位图
			// 加载位图到hdcTemp中
			HDC hdc = GetDC(hwnd);
			HDC hdcTemp = CreateCompatibleDC(hdc);
			SelectObject(hdcTemp, g_hBitmap);

			// 得到窗口大小
			int nWidth, nHeight;
			GetWindowSize(hwnd, &nWidth, &nHeight);

			// 创建与窗口大小相等且能容纳位图的HDC - s_hdcMem
			s_hdcMem = CreateCompatibleDC(hdc);
			HBITMAP hbmp = CreateCompatibleBitmap(hdc, nWidth, nHeight);
			SelectObject(s_hdcMem, hbmp);

			// 将原位图缩放到窗口大小
			BITMAP bm;
			GetObject(g_hBitmap, sizeof(bm), &bm);
			StretchBlt(s_hdcMem, 0, 0, nWidth, nHeight, hdcTemp, 0, 0, bm.bmWidth, bm.bmHeight, SRCCOPY);
			
			// 释放资源
			DeleteDC(hdcTemp);
			ReleaseDC(hwnd, hdc);
		}
		return 0;

		
	case WM_KEYDOWN: 
		switch (wParam)
		{
		case VK_ESCAPE: //按下Esc键时退出
			SendMessage(hwnd, WM_DESTROY, 0, 0);
			return TRUE;
		}
		break;
	

	case WM_LBUTTONDOWN: //当鼠标左键点击时可以拖曳窗口
		PostMessage(hwnd, WM_SYSCOMMAND, SC_MOVE | HTCAPTION, 0); 
		return TRUE;
				
	case WM_ERASEBKGND: //在窗口背景中直接贴图
		{
			HDC hdc = (HDC)wParam;
			int nWidth, nHeight;
			GetWindowSize(hwnd, &nWidth, &nHeight);
			BitBlt(hdc, 0, 0, nWidth, nHeight, s_hdcMem, 0, 0, SRCCOPY);
			return TRUE;
		}

	case WM_DESTROY:
		DeleteDC(s_hdcMem);
		PostQuitMessage(0);
		return 0;
	}
	return DefWindowProc(hwnd, message, wParam, lParm);
}


void GetWindowSize(HWND hwnd, int *pnWidth, int *pnHeight)
{
	RECT rc;
	GetWindowRect(hwnd, &rc);
	*pnWidth = rc.right - rc.left;
	*pnHeight = rc.bottom - rc.top;
}

运行程序将得到如文章中每一张图右边所示的异形窗口。

最后总结一下异形窗口的“三要素”：

1．WS_EX_LAYERED属性

2．以位图为窗口背景（自贴图或位图画刷）

3．指定透明色

本文配套程序下载地址为：http://download.csdn.net/download/morewindows/4966819

当窗口的背景用彩色图片来装饰时，其它控件如果还是用灰色的背景会显的比较不谐调，《Windows界面编程第五篇 静态控件背景透明化》将介绍如何为静态框设置透明背景。