图像未加载图像

Question

我只想为 UIButton 设置图像并为其创建一个 IBOutlet。我在它上面有一个加载器，当加载图像时，加载器将停止并为该按钮分配一个新图像。调用代码时，占位符图像仍然存在，url 图像未加载

  [_Image1 sd_setBackgroundImageWithURL:[NSURL URLWithString:[arrayGallery valueForKey:@"link"][0]] forState:UIControlStateNormal placeholderImage:[UIImage imageNamed:@"blurred-background"] completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) {
        [_ImageLoader1 stopAnimating];
        [_ImageLoader1 removeFromSuperview];
    }];

Answer 1

如果您正在为 SDWebImageCache 使用完成块，请在完成块内设置图像

[_Image1 sd_setBackgroundImageWithURL:[NSURL URLWithString:[arrayGallery valueForKey:@"link"][0]] forState:UIControlStateNormal placeholderImage:[UIImage imageNamed:@"blurred-background"] completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) {
        _Image1.image = image;
        [_ImageLoader1 stopAnimating];
        [_ImageLoader1 removeFromSuperview];
    }];

Answer 2

在主线程中更新图像尝试这样的事情

 [_Image1 sd_setBackgroundImageWithURL:[NSURL URLWithString:[arrayGallery valueForKey:@"link"][0]] forState:UIControlStateNormal placeholderImage:[UIImage imageNamed:@"blurred-background"] completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) {
        [_ImageLoader1 stopAnimating];
        [_ImageLoader1 removeFromSuperview];

        dispatch_sync(dispatch_get_main_queue(), ^{
           _Image1.image = image;   
        });

 }];

Answer 3

您正在使用完成块从 url 下载图像。所以你需要按照下面的方式去做。

 [_Image1 sd_setBackgroundImageWithURL:[NSURL URLWithString:[arrayGallery valueForKey:@"link"][0]] forState:UIControlStateNormal placeholderImage:[UIImage imageNamed:@"blurred-background"] completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) {

            [_Image1 setImage:btnImage forState:UIControlStateNormal];//Don't forgot to check for error if error is nil or image is not nil then only set image

            [_ImageLoader1 stopAnimating];
            [_ImageLoader1 removeFromSuperview];
  }];

Answer 4

从 NSUrlRequest 和 NSUrl URLWithString "your url"

得到 NSData

并将NSData转换为UIImage并设置背景图片。

Answer 5

首先获取图像url并检查图像url长度是否大于零/不null。并确保图像 url 是否正常工作。在 Browser 上点击 url 并检查您是否获得了正确的图像。

SDWebImage 库正在更新按钮图像，但这在 Main Thread 上没有发生。这可能是不更新 UIButton 的 backgroundImage 的原因。

- (void)sd_setBackgroundImageWithURL:(nullable NSURL *)url
forState:(UIControlState)state
placeholderImage:(nullable UIImage *)placeholder
options:(SDWebImageOptions)options
completed:(nullable SDExternalCompletionBlock)completedBlock {
    if (!url) {
        [self.imageURLStorage removeObjectForKey:@(state)];
        return;
    }

    NSString *imageURL = [arrayGallery valueForKey:@"link"][0];
    self.imageURLStorage[@(state)] = url;

    __weak typeof(self)weakSelf = self;
    [self sd_internalSetImageWithURL:url
                    placeholderImage:placeholder
                             options:options
                        operationKey:[NSString stringWithFormat:@"UIButtonBackgroundImageOperation%@", @(state)]
                       setImageBlock:^(UIImage *image, NSData *imageData) {
                           [weakSelf setBackgroundImage:image forState:state];
                       }
                            progress:nil
                           completed:completedBlock];
}

停止 loader 动画并在 main thread 上设置 UIButton 背景图像。

NSString *imageURL = [arrayGallery valueForKey:@"link"][0];

if (imageURL.length > 0) {

    [_Image1 sd_setBackgroundImageWithURL:[NSURL URLWithString:imageURL] forState:UIControlStateNormal placeholderImage:[UIImage imageNamed:@"blurred-background"] completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) {
        dispatch_async(dispatch_get_main_queue(), ^{
            [_ImageLoader1 stopAnimating];
            [_ImageLoader1 removeFromSuperview];
            [_Image1 setBackgroundImage:image forState:UIControlStateNormal];
        });
    }];

}

图像未加载图像

Image not loading for image

objective-c

input-button-image

ios