如何通过NSBundleResourceRequest下载后访问资源目录（图片）？

Question

在通过NSBundleResourceRequest（按需资源）下载资产目录后，我无法访问资产目录中的图像。

我的代码，形象地说集名称是“snow_4”点播资源标签“标签1”

NSBundleResourceRequest* resourceRequest = [[NSBundleResourceRequest alloc] initWithTags:[NSSet setWithObjects:@"tag1", nil]]; 

[resourceRequest conditionallyBeginAccessingResourcesWithCompletionHandler: 
^(BOOL resourcesAvailable){ 
    // if resource is not available download it 
    if (!resourcesAvailable) { 
     [resourceRequest beginAccessingResourcesWithCompletionHandler: 
      ^(NSError * __nullable error){ 
       if(!error){      
        UIImage* image = [UIImage imageNamed:@"snow_4"]; // image is null 
       } 
      }]; 
    }else{    
     UIImage* image = [UIImage imageNamed:@"snow_4"]; // image is null 
    } 
}]; 

下面是我的磁盘报告，请注意，[UIImage的imageNamed：@“snow_3”（标记为“使用中”）返回一个正确的对象，但没有图像被标记为“已下载”

欣赏你的时间和帮助！

谢谢， 火星

Answer 1

为此

图像= [UIImage的imageNamaed：@ “snow_4” inBundle：[resourceRequest捆绑]];

Answer 2

let tags = NSSet(array: ["tag1","tag2"]) 
let resourceRequest = NSBundleResourceRequest(tags: tags as! Set<String>) 
resourceRequest.conditionallyBeginAccessingResourcesWithCompletionHandler {(resourcesAvailable: Bool) -> Void in 
    if resourcesAvailable { 
     // Do something with the resources 
    } else { 
     resourceRequest.beginAccessingResourcesWithCompletionHandler {(err: NSError?) -> Void in 
      if let error = err { 
       print("Error: \(error)") 
      } else { 
       // Do something with the resources 
      } 
     } 
    } 
}