截取整个屏幕大小:

1 UIGraphicsBeginImageContext(self.view.bounds.size);2  3 [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];4      5 UIImage * viewImage = UIGraphicsGetImageFromCurrentImageContext();6      7 UIGraphicsEndImageContext();8      9 UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil)

截取自定义大小：

1 UIGraphicsBeginImageContext(_attributedLabel.frame.size);2 [_attributedLabel.layer renderInContext:UIGraphicsGetCurrentContext()];3 UIImage * viewImage = UIGraphicsGetImageFromCurrentImageContext();4 UIGraphicsEndImageContext();5 UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);

项目需要导入QuartzCore.framework