Ios 如何从url加载图像并共享该图像？

我想使用

UIActivityViewController

共享图像。 这是我的密码

- (IBAction)shareBUttonClick:(id)sender
{
   for(int i=0; i<[self.imagesDataArray count];i++)
  {
     [imageView sd_setImageWithURL:[NSURL URLWithString:[self.imagesDataArray objectAtIndex:i]] placeholderImage:[UIImage imageNamed:@"placeholder.png"]];  
     NSArray *postItems=@[imageView];
    UIActivityViewController *controller = [[UIActivityViewController alloc] initWithActivityItems:postItems applicationActivities:nil];

 //if iPhone
 if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
    {
    [self presentViewController:controller animated:YES completion:nil];
    }
//if iPad
else 
    {
    // Change Rect to position Popover
    UIPopoverController *popup = [[UIPopoverController alloc] initWithContentViewController:controller];
    [popup presentPopoverFromRect:CGRectMake(self.view.frame.size.width/2, self.view.frame.size.height/4, 0, 0)inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
    }
 }
}

-（iAction）共享按钮单击：（id）发件人
{
对于（inti=0；i，首先需要准备所有URL和预取图像

    NSMutableArray * urls = [NSMutableArray   arrayWithCapacity:things.count];
    for(int i=0; i<[self.imagesDataArray count];i++) {
        [urls addObject:[NSURL URLWithString:   self.imagesDataArray[i]]];
    }
    [SDWebImagePrefetcher sharedImagePrefetcher]

NSMutableArray*url=[NSMutableArray-withcapacity:things.count]；
对于（inti=0；i，首先需要准备所有URL和预取图像

    NSMutableArray * urls = [NSMutableArray   arrayWithCapacity:things.count];
    for(int i=0; i<[self.imagesDataArray count];i++) {
        [urls addObject:[NSURL URLWithString:   self.imagesDataArray[i]]];
    }
    [SDWebImagePrefetcher sharedImagePrefetcher]

NSMutableArray*url=[NSMutableArray-withcapacity:things.count]；
对于（int i=0；i您可以使用sdwebimage downloader async，然后调用upload函数：

 [[SDWebImageDownloader sharedDownloader] downloadImageWithURL:[NSURL URLWithString:imageUrl] options:SDWebImageDownloaderUseNSURLCache progress:nil completed:^(UIImage *image, NSData *data, NSError *error, BOOL finished) {

                        if (image && finished) {
    // now upload   
                              [self sendImageToShare:(UIImage *)image];
                        }
                    }]; 


    /*********************/


    - (void)sendImageToShare:(UIImage *)yourImage {
        if (yourImage) {
        NSMutableArray *activityItems= [NSMutableArray arrayWithObjects:yourImage, nil];
        UIActivityViewController *activityViewController = [[UIActivityViewController alloc] initWithActivityItems:activityItems applicationActivities:nil];

        [self presentViewController:activityViewController animated:YES completion:nil];
    }

     }

您可以使用sdwebimage downloader async，然后调用upload函数：

 [[SDWebImageDownloader sharedDownloader] downloadImageWithURL:[NSURL URLWithString:imageUrl] options:SDWebImageDownloaderUseNSURLCache progress:nil completed:^(UIImage *image, NSData *data, NSError *error, BOOL finished) {

                        if (image && finished) {
    // now upload   
                              [self sendImageToShare:(UIImage *)image];
                        }
                    }]; 


    /*********************/


    - (void)sendImageToShare:(UIImage *)yourImage {
        if (yourImage) {
        NSMutableArray *activityItems= [NSMutableArray arrayWithObjects:yourImage, nil];
        UIActivityViewController *activityViewController = [[UIActivityViewController alloc] initWithActivityItems:activityItems applicationActivities:nil];

        [self presentViewController:activityViewController animated:YES completion:nil];
    }

     }

您是否检查图像是否已添加或未分配imageView的内存我是ios新手，您告诉我该怎么做？如果我是静态添加的图像，则其工作文件，但我的图像来自url。请尝试此
NSArray*positems=@[imageView]；
在此处使用
NSArray*positems=@[imageView.image]；
警告：尝试显示已显示的图像（null）此错误您是否检查图像是否已添加或未分配imageView的内存我是ios新手，您告诉我该怎么办？如果我是静态添加的图像，则它的工作文件，但我的图像来自url。尝试此
NSArray*positems=@[imageView]
在此位置使用
NSArray*positems=@[imageView.image]；
警告：尝试显示已显示的内容（null）此错误代码正常，但我需要，直接将图像放入共享控制器。code正常，但我需要，直接将图像放入共享控制器。