on-demand-resources - 通过 NSBundleResourceRequest 下载后如何访问 Asset Catalog（图像）？

Question

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，假设图像集名称为“snow_4”，按需资源标签为“tag1”

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
     }
 }];

以下是我的磁盘报告，请注意 [UIImage imageNamed:@"snow_3"]（标记为“使用中”）返回正确的对象，但不返回标记为“已下载”的图像

感谢您的时间和帮助！

谢谢，火星

Answer 1

确保NSBundleResourceRequest不提前发布。尝试让NSBundleResourceRequest变量全局，并访问图像UIImage(named: "xxx", in: self.bundleReq.bundle, compatibleWith: nil)

Answer 2

做这个

image = [UIImage imageNamaed:@"snow_4" inBundle:[resourceRequest bundle]];

Answer 3

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
            }
        }
    }
}