我正在使用AFNetworking库来设置URL的内容.在以下示例中,topLeft
Image是UI
ImageView的一个实例.
- [topLeftImage setImageWithURL:[NSURL URLWithString:imageURL]];
我想做的是在图像下载时显示一个UIActivityIndicatorView.但是,我无法确定触发活动指示器的启动和停止的位置.以下是我的活动指标代码.@H_404_5@
- UIActivityIndicatorView *activityIndicator = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
- [topLeftImage addSubview:activityIndicator];
- [activityIndicator startAnimating];
解决方法
UIImageView AFNetworking.h类别提供了一个setImageWithURL方法,允许您使用成功和失败的块.一旦请求完成成功或失败,该块将被执行.所以你可以在请求之前启动动画并将其停止在成功和失败的块.这是一个示例代码:
- NSURL *imageURL = [NSURL URLWithString:@"http://upload.wikimedia.org/wikipedia/commons/thumb/e/ec/Mona_Lisa%2C_by_Leonardo_da_Vinci%2C_from_C2RMF_retouched.jpg/402px-Mona_Lisa%2C_by_Leonardo_da_Vinci%2C_from_C2RMF_retouched.jpg"];
- NSURLRequest *imageRequest = [NSURLRequest requestWithURL:imageURL];
- [_activityIndicator setHidden:NO];
- [_activityIndicator startAnimating];
- [_imageView setImageWithURLRequest:imageRequest
- placeholderImage:nil
- success:^(NSURLRequest *request,NSHTTPURLResponse *response,UIImage *image)
- {
- [_activityIndicator setHidden:YES];
- [_activityIndicator stopAnimating];
- _imageView.image = image;
- }
- failure:^(NSURLRequest *request,NSError *error)
- {
- [_activityIndicator setHidden:YES];
- [_activityIndicator stopAnimating];
- }];