屏幕部分的屏幕截图

Question

如果您按UIButton，如何制作屏幕部分的屏幕截图？ 我已经搜索了很多，但我找不到有效的答案。 Xcode是整个时间抱怨，有人可以给我一个适用于iOS 6的代码吗？

Answer 1

您可以使用此代码（未测试）：

UIGraphicsBeginImageContext(USE UR SCREEN PART); 
[self.window.layer renderInContext:UIGraphicsGetCurrentContext()]; 
UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); 
UIGraphicsEndImageContext(); 
NSData * data = UIImagePNGRepresentation(image); 
[data writeToFile:@"yourscreenshot.png" atomically:YES]; 

只是在UIGraphicsBeginImageContext括号设置你的屏幕部分的相关信息。

Answer 2

为了捕捉一个特定视图：

UIView *theView = self.view; 
CGSize imageSize = [theView bounds].size 
UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0); 
CGContextRef context = UIGraphicsGetCurrentContext(); 
[[theView layer] renderInContext:context]; 
UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); 
UIGraphicsEndImageContext(); 

现在，您可以保存生成的图像或做任何你想用它。

Answer 3

我以前写过这个小类。你可以使用它。后者的功能获得了整个屏幕的截图（它是从苹果的向导中获得的，所以它绝对安全）。我添加的第一部分处理不同的尺度（视网膜或常规）。愿它有所帮助。

#import "ScreenshotTaker.h" 
#import <QuartzCore/QuartzCore.h> 

@implementation ScreenshotTaker 


+(UIImage *) captureRectOfScreen:(CGRect) rect 
{ 
    UIImage *wholeScreen = [ScreenshotTaker screenshot]; 

    //Add status bar height 
    rect.origin.y += UIInterfaceOrientationIsLandscape([UIApplication sharedApplication].statusBarOrientation) ? [[UIApplication sharedApplication] statusBarFrame].size.width : [[UIApplication sharedApplication] statusBarFrame].size.height; 

    //NSLog(@"%@",NSStringFromCGSize([wholeScreen size])); 

    CGFloat scale = wholeScreen.scale; 

    rect.origin.x *= scale; 
    rect.origin.y *= scale; 
    rect.size.width *= scale; 
    rect.size.height *= scale; 

    UIImage *cropped = [UIImage imageWithCGImage:CGImageCreateWithImageInRect([wholeScreen CGImage], rect) scale:wholeScreen.scale orientation:wholeScreen.imageOrientation]; 

    //NSLog(@"Whole Screen Capt :%@ Scale: %f",NSStringFromCGSize([wholeScreen size]), wholeScreen.scale); 
    //NSLog(@"Rect to Crop :%@ Cropped :%@",NSStringFromCGRect(rect), NSStringFromCGSize([cropped size])); 

    return cropped; 
} 

+(UIImage *) screenshot 
{ 
    // Create a graphics context with the target size 
    // On iOS 4 and later, use UIGraphicsBeginImageContextWithOptions to take the scale into consideration 
    // On iOS prior to 4, fall back to use UIGraphicsBeginImageContext 
    CGSize imageSize = [[UIScreen mainScreen] bounds].size; 
    if (NULL != UIGraphicsBeginImageContextWithOptions) 
     UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0); 
    else 
     UIGraphicsBeginImageContext(imageSize); 

    CGContextRef context = UIGraphicsGetCurrentContext(); 

    // Iterate over every window from back to front 
    for (UIWindow *window in [[UIApplication sharedApplication] windows]) 
    { 
     if (![window respondsToSelector:@selector(screen)] || [window screen] == [UIScreen mainScreen]) 
     { 
      // -renderInContext: renders in the coordinate space of the layer, 
      // so we must first apply the layer's geometry to the graphics context 
      CGContextSaveGState(context); 
      // Center the context around the window's anchor point 
      CGContextTranslateCTM(context, [window center].x, [window center].y); 
      // Apply the window's transform about the anchor point 
      CGContextConcatCTM(context, [window transform]); 
      // Offset by the portion of the bounds left of and above the anchor point 
      CGContextTranslateCTM(context, 
            -[window bounds].size.width * [[window layer] anchorPoint].x, 
            -[window bounds].size.height * [[window layer] anchorPoint].y); 

      // Render the layer hierarchy to the current context 
      [[window layer] renderInContext:context]; 

      // Restore the context 
      CGContextRestoreGState(context); 
     } 
    } 

    // Retrieve the screenshot image 
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); 

    UIGraphicsEndImageContext(); 

    return image; 
} 

@end