我的Android应用程序存在问题。 有时它会在启动时崩溃，但有时却没有。 可悲的是，LogCat并没有帮助我，我也不知道出了什么问题。
我的应用使用AsyncTask从互联网上获取和处理数据。
什么可能导致问题？
这是LogCat日志：
01-03 21:43:29.998: D/AbsListView(28500): Get MotionRecognitionManager
01-03 21:43:30.008: D/ProgressBar(28500): setProgress = 0
01-03 21:43:30.008: D/ProgressBar(28500): setProgress = 0, fromUser = false
01-03 21:43:30.008: D/ProgressBar(28500): mProgress = 0mIndeterminate = false, mMin = 0, mMax = 10000
01-03 21:43:30.038: D/AbsListView(28500): onVisibilityChanged() is called, visibility : 4
01-03 21:43:30.038: D/AbsListView(28500): unregisterIRListener() is called
01-03 21:43:30.038: D/AbsListView(28500): onVisibilityChanged() is called, visibility : 0
01-03 21:43:30.038: D/AbsListView(28500): unregisterIRListener() is called
01-03 21:43:30.179: D/libEGL(28500): loaded /vendor/lib/egl/libEGL_adreno.so
01-03 21:43:30.189: D/libEGL(28500): loaded /vendor/lib/egl/libGLESv1_CM_adreno.so
01-03 21:43:30.189: D/libEGL(28500): loaded /vendor/lib/egl/libGLESv2_adreno.so
01-03 21:43:30.189: I/Adreno-EGL(28500): <qeglDrvAPI_eglInitialize:316>: EGL 1.4 QUALCOMM build: (CL4169980)
01-03 21:43:30.189: I/Adreno-EGL(28500): OpenGL ES Shader Compiler Version: 17.01.10.SPL
01-03 21:43:30.189: I/Adreno-EGL(28500): Build Date: 09/26/13 Thu
01-03 21:43:30.189: I/Adreno-EGL(28500): Local Branch:
01-03 21:43:30.189: I/Adreno-EGL(28500): Remote Branch:
01-03 21:43:30.189: I/Adreno-EGL(28500): Local Patches:
01-03 21:43:30.189: I/Adreno-EGL(28500): Reconstruct Branch:
01-03 21:43:30.239: D/OpenGLRenderer(28500): Enabling debug mode 0
01-03 21:43:30.239: D/ProgressBar(28500): updateDrawableBounds: left = 0
01-03 21:43:30.239: D/ProgressBar(28500): updateDrawableBounds: top = 0
01-03 21:43:30.239: D/ProgressBar(28500): updateDrawableBounds: right = 144
01-03 21:43:30.239: D/ProgressBar(28500): updateDrawableBounds: bottom = 144
01-03 21:43:30.239: D/AbsListView(28500): unregisterIRListener() is called
01-03 21:43:30.249: D/AbsListView(28500): unregisterIRListener() is called
01-03 21:43:30.479: D/AndroidRuntime(28500): Shutting down VM
01-03 21:43:30.479: W/dalvikvm(28500): threadid=1: thread exiting with uncaught exception (group=0x418c6898)
01-03 21:43:30.489: E/AndroidRuntime(28500): FATAL EXCEPTION: main
01-03 21:43:30.489: E/AndroidRuntime(28500): java.lang.IllegalStateException: The content of the adapter has changed but ListView did not receive a notification. Make sure the content of your adapter is not modified from a background thread, but only from the UI thread. [in ListView(2131427329, class android.widget.ListView) with Adapter(class se.taby10.application.NewsList)]
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.widget.ListView.layoutChildren(ListView.java:1557)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.widget.AbsListView.onLayout(AbsListView.java:2444)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.view.View.layout(View.java:15204)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.view.ViewGroup.layout(ViewGroup.java:4793)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1076)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.view.View.layout(View.java:15204)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.view.ViewGroup.layout(ViewGroup.java:4793)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.view.View.layout(View.java:15204)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.view.ViewGroup.layout(ViewGroup.java:4793)
01-03 21:43:30.489: E/AndroidRuntime(28500): at com.android.internal.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:349)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.view.View.layout(View.java:15204)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.view.ViewGroup.layout(ViewGroup.java:4793)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.view.View.layout(View.java:15204)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.view.ViewGroup.layout(ViewGroup.java:4793)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2258)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2005)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1247)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6355)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:791)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.view.Choreographer.doCallbacks(Choreographer.java:591)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.view.Choreographer.doFrame(Choreographer.java:561)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:777)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.os.Handler.handleCallback(Handler.java:730)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.os.Handler.dispatchMessage(Handler.java:92)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.os.Looper.loop(Looper.java:137)
01-03 21:43:30.489: E/AndroidRuntime(28500): at android.app.ActivityThread.main(ActivityThread.java:5419)
01-03 21:43:30.489: E/AndroidRuntime(28500): at java.lang.reflect.Method.invokeNative(Native Method)
01-03 21:43:30.489: E/AndroidRuntime(28500): at java.lang.reflect.Method.invoke(Method.java:525)
01-03 21:43:30.489: E/AndroidRuntime(28500): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1187)
01-03 21:43:30.489: E/AndroidRuntime(28500): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
01-03 21:43:30.489: E/AndroidRuntime(28500): at dalvik.system.NativeStart.main(Native Method)
01-03 21:43:33.262: I/Process(28500): Sending signal. PID: 28500 SIG: 9
代码：
package se.taby10.application;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.preference.PreferenceManager;
import android.text.Html;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
public class MainActivity extends Activity {
Button btnWebsite, btnCourses;
ListView newsList;
ArrayList<Item> newsArrayList;
ArrayAdapter<Item> newsAdapter;
Context context;
SharedPreferences settings;
String feedUrl = "http://taby10.se/feed.php?encoding=json";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
context = this;
newsList = (ListView) findViewById(R.id.newsList);
settings = PreferenceManager
.getDefaultSharedPreferences(getBaseContext());
newsArrayList = new ArrayList<Item>();
newsAdapter = new NewsList(MainActivity.this, newsArrayList);
newsList.setAdapter(newsAdapter);
newsList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// Set up intent and pass item data
Intent intent = new Intent("se.taby10.application.SINGLENEWS");
intent.putExtra("ItemId", newsArrayList.get(position).getId());
intent.putExtra("ItemTitle", newsArrayList.get(position)
.getTitle());
intent.putExtra("ItemContent", newsArrayList.get(position)
.getContent());
intent.putExtra("ItemTimestamp", newsArrayList.get(position)
.getTimestamp());
intent.putExtra("ItemUrl", newsArrayList.get(position).getUrl());
// Start activity to show news in
startActivity(intent);
}
});
// Buttons
btnWebsite = (Button) findViewById(R.id.btnWebsite);
btnWebsite.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent websiteIntent = new Intent(Intent.ACTION_VIEW);
websiteIntent.setData(Uri.parse("http://taby10.se"));
startActivity(websiteIntent);
}
});
btnCourses = (Button) findViewById(R.id.btnCourses);
btnCourses.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent coursesIntent = new Intent(Intent.ACTION_VIEW);
coursesIntent.setData(Uri.parse("http://taby10.se/courses"));
startActivity(coursesIntent);
}
});
// Load feed
NewsListTask loaderTask = new NewsListTask();
loaderTask.execute();
refresh();
}
@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;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_about:
startActivity(new Intent("se.taby10.application.ABOUT"));
break;
case R.id.action_settings:
startActivity(new Intent("se.taby10.application.SETTINGS"));
break;
}
return false;
}
public void refresh() {
int updateFrequency = settings.getInt("updatefrequency", 600);
if (updateFrequency != 0) {
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
// Reload news feed
NewsListTask loaderTask = new NewsListTask();
loaderTask.execute();
// Reset timer
refresh();
}
}, updateFrequency * 1000);
}
}
public class NewsListTask extends AsyncTask<Void, Void, Void> {
ProgressDialog dialog;
@Override
protected void onPreExecute() {
dialog = new ProgressDialog(context);
dialog.setTitle("Hämtar nyheter");
dialog.setMessage("Vänta medan nyheter laddas. Detta kan ta ett tag.");
dialog.setCancelable(false);
dialog.show();
super.onPreExecute();
}
@Override
protected Void doInBackground(Void... params) {
HttpClient client = new DefaultHttpClient();
HttpGet getRequest = new HttpGet(feedUrl);
try {
HttpResponse response = client.execute(getRequest);
StatusLine statusLine = response.getStatusLine();
int statusCode = statusLine.getStatusCode();
if (statusCode != 200) {
return null;
}
InputStream jsonStream = response.getEntity().getContent();
BufferedReader reader = new BufferedReader(
new InputStreamReader(jsonStream));
StringBuilder builder = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
builder.append(line);
}
String jsonData = builder.toString();
JSONArray json = new JSONArray(jsonData);
// Get items from json
for (int i = 0; i < json.length(); i++) {
JSONObject e = json.getJSONObject(i);
Item objItem = new Item();
objItem.setId(e.getInt("id"));
objItem.setTitle(Html.fromHtml(
Html.fromHtml(e.getString("title")).toString())
.toString());
objItem.setDescription(Html.fromHtml(
Html.fromHtml(e.getString("description"))
.toString()).toString());
objItem.setContent(Html.fromHtml(
Html.fromHtml(e.getString("content")).toString())
.toString());
objItem.setTimestamp(Html
.fromHtml(e.getString("timestamp")).toString());
objItem.setUrl(Html.fromHtml(e.getString("link"))
.toString());
newsArrayList.add(objItem); // Add item to list
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result) {
dialog.dismiss();
newsAdapter.notifyDataSetChanged();
super.onPostExecute(result);
}
}
}
答案 0 :(得分：0)
好的，你有某种List为你的适配器提供数据？ 如果是这种情况，则不应在其他线程中修改它。你应该获取数据，当你有新的List时，然后将它传递给适配器并调用notifydatasetchanged方法来更新它。
logcat表示您正在更改适配器的数据而不通知！