android - doInBackground() で AsyncTask がクラッシュする

Question

このアダプターにデータを読み込もうとしていることがわかりますが、AsyncTask を作成して進行状況ダイアログを表示することはできません。

これは、エラーが発生するプログラムの完全なコードです。完全に修正したので、UI は一切編集しません。

public class MatchNowGames extends Activity {
Games games = new Games();
Iterator iterador;
private ProgressDialog dialog;
GamesArrayAdapter adapter;
ListView lv;
public void onCreate(Bundle savedInstanceState) {       
    super.onCreate(savedInstanceState);        
    // INCIO PROGRAMA        
    setContentView(R.layout.games_list);
    lv = (ListView) this.findViewById(R.id.gamesLV);
    // Creamos el thread
    dialog = new ProgressDialog(this);
    dialog.setMessage("Cargando...");
    dialog.setTitle("Progreso");
    dialog.setCancelable(false);

    // INIT VARIABLES
    new CargandoJuegos().execute(); 
    adapter = new GamesArrayAdapter(App.context().getApplicationContext(), R.layout.games_list, games.getGames());      


}
private class CargandoJuegos extends AsyncTask<Void, Void, Void>{
    protected void onPreExecute() {
            dialog.show();
            }

     protected Void doInBackground(Void... urls) {
         // AÑADIMOS LOS JUEGOS
        try {
            games.addGames(MatchNow.serverGames);
            try {
                Thread.sleep(5000);
            } catch (InterruptedException e) {

                e.printStackTrace();
            }
        } catch (JSONException e) {}
        return null;
     }
     protected void onPostExecute(Void unused) {
         dialog.dismiss();
         lv.setAdapter(adapter);
     }


  }

}

そして、これはプログレスダイアログを表示している間に私たちがすべきことです:

// Start progress dialog
    try {
            games.addGames(MatchNow.serverGames);
        } catch (JSONException e) {
            e.printStackTrace();
        }
    // Finish progress dialog
    GamesArrayAdapter adapter = new GamesArrayAdapter(App.context().getApplicationContext(), R.layout.games_list, games.getGames());
    ListView lv = (ListView) this.findViewById(R.id.gamesLV);
    lv.setAdapter(adapter);

よろしくお願いします=）

ログキャット:

09-07 02:18:07.916: D/AndroidRuntime(890): Shutting down VM
09-07 02:18:07.916: W/dalvikvm(890): threadid=3: thread exiting with uncaught exception (group=0x4001b188)
09-07 02:18:07.926: E/AndroidRuntime(890): Uncaught handler: thread main exiting due to uncaught exception
09-07 02:18:07.936: E/AndroidRuntime(890): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{match.now.play/match.now.play.MatchNowGames}: java.lang.NullPointerException
09-07 02:18:07.936: E/AndroidRuntime(890):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2417)
09-07 02:18:07.936: E/AndroidRuntime(890):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
09-07 02:18:07.936: E/AndroidRuntime(890):  at android.app.ActivityThread.access$2200(ActivityThread.java:119)
09-07 02:18:07.936: E/AndroidRuntime(890):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
09-07 02:18:07.936: E/AndroidRuntime(890):  at android.os.Handler.dispatchMessage(Handler.java:99)
09-07 02:18:07.936: E/AndroidRuntime(890):  at android.os.Looper.loop(Looper.java:123)
09-07 02:18:07.936: E/AndroidRuntime(890):  at android.app.ActivityThread.main(ActivityThread.java:4363)
09-07 02:18:07.936: E/AndroidRuntime(890):  at java.lang.reflect.Method.invokeNative(Native Method)
09-07 02:18:07.936: E/AndroidRuntime(890):  at java.lang.reflect.Method.invoke(Method.java:521)
09-07 02:18:07.936: E/AndroidRuntime(890):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
09-07 02:18:07.936: E/AndroidRuntime(890):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
09-07 02:18:07.936: E/AndroidRuntime(890):  at dalvik.system.NativeStart.main(Native Method)
09-07 02:18:07.936: E/AndroidRuntime(890): Caused by: java.lang.NullPointerException
09-07 02:18:07.936: E/AndroidRuntime(890):  at android.app.Activity.findViewById(Activity.java:1612)
09-07 02:18:07.936: E/AndroidRuntime(890):  at match.now.play.MatchNowGames.<init>(MatchNowGames.java:40)

見落としだった1612行の問題を解決しました。Logcat は本当に問題を引き起こします。ご不便おかけしてすみません。

    09-07 02:18:07.936: E/AndroidRuntime(890):  at java.lang.Class.newInstanceImpl(Native Method)
    09-07 02:18:07.936: E/AndroidRuntime(890):  at java.lang.Class.newInstance(Class.java:1479)
    09-07 02:18:07.936: E/AndroidRuntime(890):  at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
    09-07 02:18:07.936: E/AndroidRuntime(890):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2409)
    09-07 02:18:07.936: E/AndroidRuntime(890):  ... 11 more


09-07 02:34:31.486: D/dalvikvm(930): GC freed 404 objects / 23688 bytes in 60ms
09-07 02:34:32.976: I/global(930): Default buffer size used in BufferedReader constructor. It would be better to be explicit if an 8k-char buffer is required.
09-07 02:34:32.986: I/System.out(930): {"games":[{"id":"1","image":"http:\/\/cibermaniacos.com\/images\/stories\/call_of_duty_modern_warfare_3_desvelado_dest01.jpg","name":"Call Of Duty MW3","descrip":"","modes":[{"id":"1","name":"1vs1","mode_icon":"none"},{"id":"2","name":"2vs2","mode_icon":"none"}],"console":"PS3,XBOX"},{"id":"2","image":"http:\/\/www.hry-na-mobil.eu\/data\/ikonky\/hry-na-mobil-eu\/46801\/call-of-duty-world-at-war-codww-1000x1000jpg-12.png","name":"Prueba","descrip":"afafs","modes":[{"id":"1","name":"1vs1","mode_icon":"none"},{"id":"2","name":"2vs2","mode_icon":"none"}],"console":"steam,PS3"},{"id":"4","image":"http:\/\/cibermaniacos.com\/images\/stories\/call_of_duty_modern_warfare_3_desvelado_dest01.jpg","name":"Call Of Duty MW2","descrip":"AWDAWD","modes":[{"id":"1","name":"1vs1","mode_icon":"none"},{"id":"2","name":"2vs2","mode_icon":"none"}],"console":"steam,PS3"}]}                  
09-07 02:34:33.036: I/System.out(930): Call Of Duty MW2
09-07 02:34:33.046: I/System.out(930): Call Of Duty MW3
09-07 02:34:33.068: W/dalvikvm(930): threadid=15: thread exiting with uncaught exception (group=0x4001b188)
09-07 02:34:33.068: E/AndroidRuntime(930): Uncaught handler: thread AsyncTask #1 exiting due to uncaught exception
09-07 02:34:33.086: E/AndroidRuntime(930): java.lang.RuntimeException: An error occured while executing doInBackground()
09-07 02:34:33.086: E/AndroidRuntime(930):  at android.os.AsyncTask$3.done(AsyncTask.java:200)
09-07 02:34:33.086: E/AndroidRuntime(930):  at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
09-07 02:34:33.086: E/AndroidRuntime(930):  at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
09-07 02:34:33.086: E/AndroidRuntime(930):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
09-07 02:34:33.086: E/AndroidRuntime(930):  at java.util.concurrent.FutureTask.run(FutureTask.java:137)
09-07 02:34:33.086: E/AndroidRuntime(930):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1068)
09-07 02:34:33.086: E/AndroidRuntime(930):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:561)
09-07 02:34:33.086: E/AndroidRuntime(930):  at java.lang.Thread.run(Thread.java:1096)
09-07 02:34:33.086: E/AndroidRuntime(930): Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
09-07 02:34:33.086: E/AndroidRuntime(930):  at android.os.Handler.<init>(Handler.java:121)
09-07 02:34:33.086: E/AndroidRuntime(930):  at android.app.Activity.<init>(Activity.java:673)
09-07 02:34:33.086: E/AndroidRuntime(930):  at match.now.play.functions.Game.<init>(Game.java:52)
09-07 02:34:33.086: E/AndroidRuntime(930):  at match.now.play.functions.Games.addGames(Games.java:58)
09-07 02:34:33.086: E/AndroidRuntime(930):  at match.now.play.MatchNowGames$CargandoJuegos.doInBackground(MatchNowGames.java:67)
09-07 02:34:33.086: E/AndroidRuntime(930):  at match.now.play.MatchNowGames$CargandoJuegos.doInBackground(MatchNowGames.java:1)
09-07 02:34:33.086: E/AndroidRuntime(930):  at android.os.AsyncTask$2.call(AsyncTask.java:185)
09-07 02:34:33.086: E/AndroidRuntime(930):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
09-07 02:34:33.086: E/AndroidRuntime(930):  ... 4 more

Answer 1

これを参照できます: Can't create handler inside thread that has not called Looper.prepare() inside AsyncTask for ProgressDialog

Answer 2

doInBackground()メソッド内の唯一の実際のコードは次のようです。

  games.addGames(MatchNow.serverGames);

ただし、addGames()メソッドで何が起こるかは示していません。そのメソッドのUIで何かをしようとしていますか? もしそうなら、それは問題になるでしょう。

doInBackground()UI 呼び出しを直接行うためのものではありません。バックグラウンド処理中に UI を更新する必要がある場合は、内部からトリガーを呼び出すことがよくpublishProgress()ありdoInBackground()ますonProgressUpdate()。内から UI 呼び出しを行うことができますonProgressUpdate()。