objective-c - AssetsLibrary 没有按预期产生故障

Question

我有这个代码:

ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
        [library assetForURL:albumCopy
                 resultBlock:^(ALAsset *asset)  {
                     NSLog(@"success");
                     ...
}
            failureBlock:^(NSError *error) {
                    NSLog(@"fail");
                    ...
                }];
        [library autorelease];

问题是当我给它一个不存在的图像时，NSLog 会出现:

Could not find photo 1000000141
success

如果这在照片不存在时不显示，我如何才能找到？

Answer 1

解决了!

ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
        [library assetForURL:albumCopy
                 resultBlock:^(ALAsset *asset)  {
                     if (asset == nil) {
                         //Image not in photo library
                     }
                     else {
                     //Image in photo library
                     }
                 }
                failureBlock:^(NSError *error) {
                    //Error
                }];
        [library autorelease];