截全屏 并且保存相册

1.记得开启访问相机权限，否则会崩溃
//截全屏

• (UIImage *) captureScreen {
  UIWindow *keyWindow = [[UIApplication sharedApplication] keyWindow];
  CGRect rect = [keyWindow bounds];
  UIGraphicsBeginImageContext(rect.size);
  CGContextRef context = UIGraphicsGetCurrentContext();
  [keyWindow.layer renderInContext:context];
  UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
  UIGraphicsEndImageContext();
  return img;
  }
  // 保存
• (void)saveScreenshotToPhotosAlbum:(UIView *)view
  {
  UIImageWriteToSavedPhotosAlbum(@"你想保存的图片" nil, nil, nil);
  }回调方法
• (void)image: (UIImage *) image didFinishSavingWithError: (NSError *) error contextInfo: (void *) contextInfo

{
NSString *msg = nil ;

if(error != NULL){

    msg = @"保存图片失败" ;
    NSLog(@"保存失败");
   
}else{
   
    msg = @"保存图片成功" ;
    NSLog(@"保存成功");
}

}