用Cocoa截取屏幕内容并保存为图片(z)_cocoa 开发以编程方式截取整个屏幕大小-优快云博客

本文介绍如何利用Cocoa框架编写一个屏幕截图程序，实现类似Command+Shift+3的功能，通过创建临时窗口并复制屏幕内容到NSImage中来保存截图。

用Cocoa截取屏幕内容并保存为图片(z)

让我们来写一个抓屏程序吧。当然，你知道只要按command+shift+3就可以抓取当前屏幕对吧？本文介绍如何用cocoa程序来实现这一功能。

 
         - (NSImage *) captureScreenImageWithFrame: (NSRect) frame
        
         {
        
         // 获取屏幕的图形端口
        
         CGrafPtr screenPort = CreateNewPort ();
        
         Rect screenRect;
        
         GetPortBounds (screenPort, &screenRect);
        
         // 创建一个临时窗口做为容器
        
         NSWindow *grabWindow = [[NSWindow alloc] initWithContentRect: frame
        
         styleMask: NSBorderlessWindowMask
        
         backing: NSBackingStoreRetained
        
         defer: NO
        
         screen: nil];
        
         CGrafPtr windowPort = GetWindowPort ([grabWindow windowRef]);
        
         Rect windowRect;
        
         GetPortBounds (windowPort, &windowRect);
        
         SetPort (windowPort);
        
         // 将屏幕内容复制到临时窗口
        
         CopyBits (GetPortBitMapForCopyBits(screenPort),
        
         GetPortBitMapForCopyBits(windowPort),
        
         &screenRect,
        
         &windowRect,
        
         srcCopy,
        
         NULL);
        
         // 将窗口内容复制到NSImage中
        
         NSView *grabContentView = [grabWindow contentView];
        
         [grabContentView lockFocus];
        
         NSBitmapImageRep *screenRep;
        
         screenRep = [[NSBitmapImageRep alloc] initWithFocusedViewRect: frame];
        
         [grabContentView unlockFocus];
        
         NSImage *screenImage = [[NSImage alloc] initWithSize: frame.size];
        
         [screenImage addRepresentation: screenRep];
        
         // Clean up
        
         [grabWindow close];
        
         DisposePort(screenPort);
        
         return 
          (screenImage);
        
         } 
         // captureScreenImageWithFrame

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