我知道已经有很多这样的问题,但是我看不出我做错了什么.该应用程序崩溃,但未显示任何内容.另外,该错误不会在我的设备或仿真器上发生.仅在某些设备上(例如30-40％？).

无法在未调用Looper.prepare()的线程内创建处理程序

MainActivity.java

public class MainActivity extends Activity implements Runnable {

Gebruiker gebruiker = new Gebruiker();

private DatabaseHelper db;

Context context;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

context = this;

if(isOnline()){

downloadData();

} else {

AlertDialog.Builder builder = new AlertDialog.Builder(context);

builder.setMessage("Deze app vereist een actieve verbinding met het internet!")

.setCancelable(false)

.setPositiveButton("OK", new DialogInterface.OnClickListener() {

public void onClick(DialogInterface dialog, int id) {

android.os.Process.killProcess(android.os.Process.myPid());

}

});

AlertDialog alert = builder.create();

alert.show();

}

db = new DatabaseHelper(this);

}

@Override

public boolean onCreateOptionsMenu(Menu menu) {

// Inflate the menu; this adds items to the action bar if it is present.

getMenuInflater().inflate(R.menu.main, menu);

return true;

}

private ProgressDialog pDialog;

public void downloadData() {

pDialog = ProgressDialog.show(this,

"Controleren op bestaande gebruiker..", "Even geduld", true,

false);

Thread thread = new Thread(this);

thread.start();

}

public void run() {

// add downloading code here

HttpReader httpReader = new HttpReader();

String url = "*****";

url += Secure.getString(getApplicationContext().getContentResolver(),

Secure.ANDROID_ID);

JsonHelper jsonHelper = new JsonHelper();

gebruiker = jsonHelper.getGebruiker((httpReader.getTextFromUrl(url)

.trim()));

handler.sendEmptyMessage(0);

}

private Handler handler = new Handler() {

@Override

public void handleMessage(Message msg) {

pDialog.dismiss();

if (gebruiker == null) {

// ga naar aanmaken gebruiker

Intent intent = new Intent(MainActivity.this,

AanmakenUser.class);

startActivity(intent);

} else {

// ga naar hoofdmenu

db.droppen();

db.insertGebruiker(gebruiker);

Intent intent = new Intent(MainActivity.this, Hoofdmenu.class);

startActivity(intent);

// ga naar menu

}

}

};

public boolean isOnline() {

ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);

NetworkInfo netInfo = cm.getActiveNetworkInfo();

if (netInfo != null && netInfo.isConnectedOrConnecting()) {

return true;

}

return false;

}

logcat的

01-10 16:12:16.444: E/AndroidRuntime(6090): FATAL EXCEPTION: Thread-10

01-10 16:12:16.444: E/AndroidRuntime(6090): java.lang.ExceptionInInitializerError

01-10 16:12:16.444: E/AndroidRuntime(6090): at db.jochen.quizapp.MainActivity.run(MainActivity.java:68)

01-10 16:12:16.444: E/AndroidRuntime(6090): at java.lang.Thread.run(Thread.java:1019)

01-10 16:12:16.444: E/AndroidRuntime(6090): Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

01-10 16:12:16.444: E/AndroidRuntime(6090): at android.os.Handler.(Handler.java:121)

01-10 16:12:16.444: E/AndroidRuntime(6090): at android.os.AsyncTask$InternalHandler.(AsyncTask.java:421)

01-10 16:12:16.444: E/AndroidRuntime(6090): at android.os.AsyncTask$InternalHandler.(AsyncTask.java:421)

01-10 16:12:16.444: E/AndroidRuntime(6090): at android.os.AsyncTask.(AsyncTask.java:152)

01-10 16:12:16.444: E/AndroidRuntime(6090): ... 2 more

01-10 16:12:16.454: D/dalvikvm(6090): GC_CONCURRENT freed 79K, 48% free 2843K/5379K, external 3695K/4614K, paused 2ms+5ms

01-10 16:12:16.454: W/ActivityManager(278): Force finishing activity db.jochen.quizapp/.MainActivity

01-10 16:12:16.544: E/SkLayout_wtle(6090): ellipsis failed line number does not match 1 0

01-10 16:12:16.624: D/fast-dormancy(165): [FDM]: finish the match exclude list procedure, but can not match any one

01-10 16:12:16.624: D/fast-dormancy(165): [FDM]: GoDormant? 0

01-10 16:12:16.624: D/fast-dormancy(165): [FDM]: Threads Status Mutex Locked in fdm_main_loop

01-10 16:12:16.624: D/fast-dormancy(165): [FDM]: Threads Status Mutex Unlocked in fdm_main_loop

01-10 16:12:16.624: D/fast-dormancy(165): [FDM]: finish the match exclude list procedure, but can not match any one

01-10 16:12:16.624: D/fast-dormancy(165): [FDM]: GoDormant? 0

01-10 16:12:16.624: D/fast-dormancy(165): [FDM]: Threads Status Mutex Locked in fdm_main_loop

01-10 16:12:16.624: D/fast-dormancy(165): [FDM]: Threads Status Mutex Unlocked in fdm_main_loop

01-10 16:12:16.624: I/ActivityManager(278): No longer want com.sonyericsson.tvlauncher (pid 4961): hidden #16

01-10 16:12:16.664: E/WindowManager(6090): Activity db.jochen.quizapp.MainActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@2afd4aa0 that was originally added here

01-10 16:12:16.664: E/WindowManager(6090): android.view.WindowLeaked: Activity db.jochen.quizapp.MainActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@2afd4aa0 that was originally added here

01-10 16:12:16.664: E/WindowManager(6090): at android.view.ViewRoot.(ViewRoot.java:269)

01-10 16:12:16.664: E/WindowManager(6090): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148)

01-10 16:12:16.664: E/WindowManager(6090): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)

01-10 16:12:16.664: E/WindowManager(6090): at android.view.Window$LocalWindowManager.addView(Window.java:424)

01-10 16:12:16.664: E/WindowManager(6090): at android.app.Dialog.show(Dialog.java:241)

01-10 16:12:16.664: E/WindowManager(6090): at android.app.ProgressDialog.show(ProgressDialog.java:109)

01-10 16:12:16.664: E/WindowManager(6090): at android.app.ProgressDialog.show(ProgressDialog.java:97)

01-10 16:12:16.664: E/WindowManager(6090): at db.jochen.quizapp.MainActivity.downloadData(MainActivity.java:59)

01-10 16:12:16.664: E/WindowManager(6090): at db.jochen.quizapp.MainActivity.onCreate(MainActivity.java:33)

01-10 16:12:16.664: E/WindowManager(6090): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)

01-10 16:12:16.664: E/WindowManager(6090): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1623)

01-10 16:12:16.664: E/WindowManager(6090): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1675)

01-10 16:12:16.664: E/WindowManager(6090): at android.app.ActivityThread.access$1500(ActivityThread.java:121)

01-10 16:12:16.664: E/WindowManager(6090): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:943)

01-10 16:12:16.664: E/WindowManager(6090): at android.os.Handler.dispatchMessage(Handler.java:99)

01-10 16:12:16.664: E/WindowManager(6090): at android.os.Looper.loop(Looper.java:138)

01-10 16:12:16.664: E/WindowManager(6090): at android.app.ActivityThread.main(ActivityThread.java:3701)

01-10 16:12:16.664: E/WindowManager(6090): at java.lang.reflect.Method.invokeNative(Native Method)

01-10 16:12:16.664: E/WindowManager(6090): at java.lang.reflect.Method.invoke(Method.java:507)

01-10 16:12:16.664: E/WindowManager(6090): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:878)

01-10 16:12:16.664: E/WindowManager(6090): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:636)

01-10 16:12:16.664: E/WindowManager(6090): at dalvik.system.NativeStart.main(Native Method)