ios - 将图片加载到 UIButton 时不会显示

Question

我一直在使用这段代码，它工作正常：

NSData * imageData = [[NSData alloc] initWithContentsOfURL: [NSURL URLWithString: currentMovie.trailerThumb]];        
[button setBackgroundImage:[UIImage imageWithData:imageData] forState:UIControlStateNormal];
[_moviesScroll addSubview:button];

现在我正在尝试使用 AFNetworking 加载图片，如下所示：

UIImageView *testMe = [[UIImageView alloc]init];
[testMe setImageWithURL:[NSURL URLWithString:currentMovie.trailerThumb] placeholderImage:[UIImage imageNamed:@"placeHolder.png"]];        
[button setBackgroundImage:testMe.image forState:UIControlStateNormal];
[_moviesScroll addSubview:button];

我得到占位符图像很好，但原始图片不会显示。

我尝试做这样的事情：我将一个插座连接到 IB 中的 imageView 并添加了以下代码：

[_test setImageWithURL:[NSURL URLWithString:@"https://www.url.com/pic.png"] placeholderImage:[UIImage imageNamed:@"placeHolder.png"]];

图像将显示正常。但如果我这样做：

[button setBackgroundImage:_test.image forState:UIControlStateNormal];

同样，只会显示占位符。

Answer 1

我最终使用了此处添加的用户之一的提交。有了那个提交，它很简单

[button setImageWithURL:[NSURL URLWithString: currentMovie.trailerThumb] placeholderImage:[UIImage imageNamed:@"placeHolder.png"] forState:UIControlStateNormal];

Answer 2

尝试这个 ：

NSURL * photoUrl = [NSURL URLWithString:@"https://www.url.com/pic.png"];

                NSURLRequest*request = [NSURLRequest requestWithURL:photoUrl];

                __weak typeof(UIImageView) *weak_testImage = _testImage;



                [_testImage setImageWithURLRequest:request placeholderImage:[UIImage imageNamed:@"placeHolder.png"] success:^(NSURLRequest *request, NSHTTPURLResponse *response, UIImage *image) {

                    weak_testImage.image = image;

                    [button setBackgroundImage:_testImage.image forState:UIControlStateNormal];



                } failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error) {



                }];