如何长时间将uitableviewcell中的图像保存到相册

Question

我使用以下代码从互联网获取图像

 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
 {
   NSURL *imageUrl = [NSURL URLWithString:[NSString stringWithFormat:@"%@/%@",image_url, [dic objectForKey:@"imageurl"]]];
__block UIActivityIndicatorView *activityIndicator;
__weak UIImageView *weakImageView = cell.userinformationimageView;
cell.userinformationimageView.backgroundColor = [UIColor clearColor];

[cell.userinformationimageView sd_setImageWithURL:imageUrl placeholderImage:nil options:SDWebImageProgressiveDownload progress:^(NSInteger receivedSize, NSInteger expectedSize) {
    if (!activityIndicator) {
        [weakImageView addSubview:activityIndicator = [UIActivityIndicatorView.alloc initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite]];
        activityIndicator.center = weakImageView.center;
        [activityIndicator startAnimating];
    }
} completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) {
    [activityIndicator removeFromSuperview];
    activityIndicator = nil;
}];
//more codes
}

单元格太多，每个单元格都有一张图片，我加长按

UILongPressGestureRecognizer * longPressGr = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressToDo:)];
longPressGr.minimumPressDuration = 1.0;
[self.tableview addGestureRecognizer:longPressGr];

- (void)longPressToDo:(UILongPressGestureRecognizer *)gesture
{
if(gesture.state == UIGestureRecognizerStateBegan)
{
    CGPoint point = [gesture locationInView:self.tableview];
    NSIndexPath *indexPath = [self.tableview indexPathForRowAtPoint:point];
    if(indexPath == nil) return;
    NSLog(@"---->%d",[indexPath row]);
    NSDictionary *dic = [self.tableData objectAtIndex:indexPath.row];

}
}

那么如何获得我长时间点击的图像？ 我想将其保存到相册，谢谢。

Answer 1

对于您要尝试的操作，有一个更简单的解决方案。 我大概会这样

- (UITableViewCell *)tableView:(UITableView *)tableView
cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSURL *imageUrl = [NSURL URLWithString:[NSString stringWithFormat:@"%@/%@",image_url, [dic objectForKey:@"imageurl"]]];
    __block UIActivityIndicatorView *activityIndicator;
    __weak UIImageView *weakImageView = cell.userinformationimageView;

    cell.userinformationimageView.backgroundColor = [UIColor clearColor];

    //Instead of whole TableView add the gesture to the Image itself
    UILongPressGestureRecognizer * longPressGr = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressToDo:)];
    longPressGr.minimumPressDuration = 1.0;
    [cell.userinformationimageView addGestureRecognizer:longPressGr];
     cell.userinformationimageView.userInteractionEnabled = YES;
    [cell.userinformationimageView sd_setImageWithURL:imageUrl placeholderImage:nil options:SDWebImageProgressiveDownload progress:^(NSInteger receivedSize, NSInteger expectedSize) {
        if (!activityIndicator) {
            [weakImageView addSubview:activityIndicator = [UIActivityIndicatorView.alloc initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite]];
            activityIndicator.center = weakImageView.center;
            [activityIndicator startAnimating];
        }
    } completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) {
       [activityIndicator removeFromSuperview];
       activityIndicator = nil;
    }];
//more codes
}

并在手势处理函数中执行此操作

- (void)longPressToDo:(UILongPressGestureRecognizer *)gesture
{
      //Just to be sure and avoid crashes
      if ([recognizer.view isKindOfClass:[UIImageView class]] ) {
         //Get the ImageView 
         UIImageView *temp = (UIImageView*)recognizer.view;
         UIImage *requiredImage = temp.image;
         //Do whatever you want with the image
    }     
}

因此，基本上，这里发生的是将手势附加到Image而不是整个表视图，并且当手势在您的处理程序中发生时，可以访问调用该手势的UIImageView并可以从中获取Image。 您还可以将手势附加到整个单个单元（不确定用例是什么），并类似地提取ImageView和Image以供使用。