截屏并保存到本地

1>截图

- (UIImage *)captureCurrentView:(UIView *)view {
    CGRect frame = view.frame;
    // 下面的方法截图不清晰
    // UIGraphicsBeginImageContext(frame.size);
    // 使用此方法可以解决不清晰的问题
    UIGraphicsBeginImageContextWithOptions(frame.size, false, UIScreen.main.scale)
    CGContextRef contextRef = UIGraphicsGetCurrentContext();
    [view.layer renderInContext:contextRef];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}

2> 保存图片

-(void)saveImageToPhotos:(UIImage *)image {
   /*
      使用这个方法时我们可以看到头文件让我们实现
- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo;
方法
    */ 
    UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSaveWithError:contextInfo:),nil);
}

3>回调

- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {
    if (error == nil) {
        NSLog(@"保存成功");
    } else {
        NSLog(@"失败");
    }
}

4>使用Swift注意点:Swift由于是直接将OC转化成Swift语法的,所以注释没有提供相应的回调方法.这时候我们需要自己转化一下.

func image(image: UIImage, didFinishSavingWithError: NSError?,contextInfo: AnyObject) {
        if didFinishSavingWithError != nil {
          debugPrint("保存失败")
        } else {
          debugPrint("保存成功")
        }
    }