我試圖做多線程,但我已經有了一些智能手機這個堆棧跟蹤(SGS2):multitreading UI:的ExceptionInInitializerError和運行時異常的Android
java.lang.ExceptionInInitializerError
at com.android.bordeaux.code.model.AnnouncersContainer.setLoudArrayFromJSON_online(AnnouncersContainer.java:68)
at com.android.bordeaux.code.SplashscreenActivity_Second$1.run(SplashscreenActivity_Second.java:55)
Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
at android.os.Handler.<init>(Handler.java:121)
at android.os.AsyncTask$InternalHandler.<init>(AsyncTask.java:421)
at android.os.AsyncTask$InternalHandler.<init>(AsyncTask.java:421)
at android.os.AsyncTask.<clinit>(AsyncTask.java:152)
... 2 more
這是我的主要活動(閃屏)至極正在爲了幾秒鐘內觀望等待我的AsyncTask完成:
public class SplashscreenActivity_Second extends Activity
{
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.splashscreen_second);
// thread
Thread splashThread = new Thread()
{
@Override
public void run()
{
try
{
int waited = 0;
if (isInternetOn())
{
// Here I'm making my asynctask !!
AnnouncersContainer.setLoudArrayFromJSON_online(getApplicationContext());
while (waited < 5000)
{
sleep(50);
waited += 40;
}
}
else
{
AnnouncersContainer.setLoudArrayFromXML_local(getApplicationContext());
while(waited < 5000)
{
sleep(50);
waited += 60;
}
}
}
catch(InterruptedException e)
{
e.printStackTrace();
}
finally
{
Intent intent_to_tabhost = new Intent(SplashscreenActivity_Second.this, MyTabActivity.class);
startActivity(intent_to_tabhost);
finish();
}
}
};
splashThread.start();
}
}
這裏是我的AsyncTask:
public class DownloadAnnouncers extends AsyncTask<Void, Integer, Boolean>
{
public static Boolean loadFinished = false;
//JSON variables..
private static String url = null;
Context context;
public DownloadAnnouncers(Context context)
{
this.context = context;
}
@Override
protected void onPreExecute()
{
super.onPreExecute();
}
protected Boolean doInBackground(Void... params)
{
// fine retrieving all my JSON data in a global array..
}
@Override
protected void onPostExecute(Boolean downloadedArray)
{
super.onPostExecute(downloadedArray);
}
}
我知道問題是我在UI中進行多線程,但有人可以告訴我如何刪除我的循環線程,並用我的Asynctask的onPostExecute()方法替換它? (它可能是最好等待的AsyncTask完成,而不是讓等待..)
或可能是幫我糾正與多線程這個錯誤..
編輯:
我的AsyncTask:
public class DownloadAnnouncers extends AsyncTask<Void, Integer, Boolean>
{
public static Boolean loadFinished = false;
//JSON variables..
private static String url = null;
Context context;
public DownloadAnnouncers(Context context)
{
this.context = context;
}
@Override
protected void onPreExecute()
{
super.onPreExecute();
}
protected Boolean doInBackground(Void... params)
{
// fine retrieving all my JSON data in a global array..
}
@Override
protected void onPostExecute(Boolean downloadedArray)
{
super.onPostExecute(downloadedArray);
Intent intent_to_tabhost = new Intent(context, MyTabActivity.class);
intent_to_tabhost.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(intent_to_tabhost);
}
}
但現在如果我按取消鍵,我回到我的啓動畫面活動..我做不到ctx.finish()在onPostExecute方法..
最後它的工作原理,我不得不將asynctask添加到我的splashscreen活動中(asynctask wasnt內部之前),所以我可以調用finish() – eento 2013-02-10 14:40:05