Question

I have an activity that lets a user upload a photo to the web and instead of having them wait indefinitely for the image to upload I have it being done in an asynctask that handles the image upload. When the user presses the button to upload the image the I have the activity that uploads the image close and the app goes back to the earlier activity which has its own downloading process. What Im trying to figure out is what to do in the asynctask onPostExecute to get the download process in the other activity to run again. I tried just using this:

  @Override
  protected void onPostExecute(String result){
    if(result!=null){
    Main.DownloadManager.startDownloading();
      }else if(result==null){
       Toast.makeText(getBaseContext(),"Upload failed",timetoshow).show();
              }
          }

But I get no response in the main activity because I know Im not actually calling the running activity but just calling the method…..somewhere thats not instantiated or running….or at least thats what I think this does. So I guess my question is how can I pass the message to run the startDownloading() method from the asynctask of the closed activity in the currently running Main activity. Any help would be super much appreciated.

EDIT:

I was able to solve this by implementing one of the solutions bellow:

 @Override
  protected void onPostExecute(String result){
    if(result!=null){
    CustomContextClass.*Main*.DownloadManager.startDownloading();
      }else if(result==null){
       Toast.makeText(getBaseContext(),"Upload failed",timetoshow).show();
              }
          }

Answer 1

You may use a static method in DownloadManager

private static instance;

public void onCreate() {
    instance = this;
}

public static void startDownloading() {
    instance.downloadNow();
}