我编写了一个应用程序来运行 AsyncTask，部分代码如下所示。问题是当 AsyncTask 通过执行代码开始时 - “new AddImageTask().execute();” 在线程处理程序中，任务将启动，一切似乎都正确。但是，在“doInBackground”方法中的所有代码都已执行后，应用程序最终将停留在“doInBackground”方法中。该任务无法转到“onPostExecute”方法。（即不能关闭对话框......）出了什么问题？
谢谢您的帮助......
private Handler handleFetchResult = new Handler() {
@Override
public void handleMessage(Message msg) {
progressDialog.dismiss();
Log.d(TAG, "Start handle fetch result");
try {
JSONArray ja = new JSONArray(fetchResult);
Log.d(TAG, "JSON Array Length = " + ja.length());
JSONObject jo = new JSONObject();
for (int i = 0; i < ja.length(); i++) {
jo = ja.getJSONObject(i);
PhotoURLs.add(PAT_url + jo.getString("filePath"));
Log.d(TAG, PhotoURLs.get(i));
}
} catch (JSONException e) {
Log.d(TAG, "Fetch result error: " + e.getLocalizedMessage());
e.printStackTrace();
}
//TODO: display thumbnail
new AddImageTask().execute();
}//void handleMessage
};//Handler handleFetchResult
class AddImageTask extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
loadThumbnailDialog.show(SitePhotoGallery.this, "Fetch thumbnails from server",
"Loading...", true, true);
Log.d("AddImageTask.onPreExecute","onPreExecute");
}
@Override
protected Void doInBackground(Void... unused) {
// TODO Auto-generated method stub
for (String url : PhotoURLs) {
String filename = url.substring(url.lastIndexOf("/") + 1, url.length());
String thumburl = url.substring(0, url.lastIndexOf("/")+1);
imgAdapter.addItem(LoadThumbnailFromURL(thumburl + filename));
publishProgress();
}
Log.d("AddImageTask.doInBackground","doInBackground");
return null ;
}
@Override
protected void onProgressUpdate(Void... unused) {
super.onProgressUpdate();
imgAdapter.notifyDataSetChanged();
Log.d("AddImageTask.onProgressUpdate","OnProgressUpdate");
}
protected void onPostExecute(Void... unused) {
super.onPostExecute(null);
loadThumbnailDialog.dismiss();
Log.d("AddImageTask.onPostExecute","onPostExecute");
}
}