onPostExecute导致应用程序崩溃 [英] onPostExecute causing application to crash

问题描述

下面是我的 onPostExecute 方法。当我的的AsyncTask 触发它做它该做的一切，但是，当它试图执行我的 onPostExecute 我的应用程序崩溃和我得到这个消息，我的的logcat

Below is my onPostExecute method. When my AsyncTask fires it does everything that it suppose to do but when it tries to execute my onPostExecute my application crashes and I get this message in my logcat

09-14 22:45:22.481: E/AndroidRuntime(1141): FATAL EXCEPTION: main
09-14 22:45:22.481: E/AndroidRuntime(1141): java.lang.NullPointerException
09-14 22:45:22.481: E/AndroidRuntime(1141):     at com.testapp1.ListView$LoadAllData.onPostExecute(ListView.java:193)
09-14 22:45:22.481: E/AndroidRuntime(1141):     at com.testapp1.ListView$LoadAllData.onPostExecute(ListView.java:1)
09-14 22:45:22.481: E/AndroidRuntime(1141):     at android.os.AsyncTask.finish(AsyncTask.java:631)
09-14 22:45:22.481: E/AndroidRuntime(1141):     at android.os.AsyncTask.access$600(AsyncTask.java:177)
09-14 22:45:22.481: E/AndroidRuntime(1141):     at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
09-14 22:45:22.481: E/AndroidRuntime(1141):     at android.os.Handler.dispatchMessage(Handler.java:99)
09-14 22:45:22.481: E/AndroidRuntime(1141):     at android.os.Looper.loop(Looper.java:137)
09-14 22:45:22.481: E/AndroidRuntime(1141):     at android.app.ActivityThread.main(ActivityThread.java:5041)
09-14 22:45:22.481: E/AndroidRuntime(1141):     at java.lang.reflect.Method.invokeNative(Native Method)
09-14 22:45:22.481: E/AndroidRuntime(1141):     at java.lang.reflect.Method.invoke(Method.java:511)
09-14 22:45:22.481: E/AndroidRuntime(1141):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
09-14 22:45:22.481: E/AndroidRuntime(1141):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
09-14 22:45:22.481: E/AndroidRuntime(1141):     at dalvik.system.NativeStart.main(Native Method)

这是我的 onPostExecute 法

    @Override
    protected void onPostExecute(String file_URL) {

        if(file_URL.equals("0")) { 
            pDialog.dismiss();
            Toast.makeText(ListView.this, "No data found", Toast.LENGTH_SHORT).show();
            finish();

        }else{

        if (pDialog != null && pDialog.isShowing()) pDialog.dismiss();
        ListAdapter adapter = new SimpleAdapter(getBaseContext(), questionList,
                    R.layout.listelements,
                    new String[] { TAG_QUESTION_SUBJECT }, new int[] {
                    R.id.Subject,});

            setListAdapter(adapter);                

        }}}

我可以请别人有这个问题，我有帮助。

May I please have somebody help with this issue that I have.

推荐答案

只需选中FILE_URL：如果（！FILE_URL = NULL＆放大器;＆安培; file_URL.equals（0））

Simply check file_URL :if(file_URL!=null && file_URL.equals("0"))

这篇关于onPostExecute导致应用程序崩溃的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！