Question

当我在模拟器上运行我的Android应用程序时崩溃（不幸的是，CursoLoader已经停止）。我在logcat中遇到以下错误：

01-05 14:46:45.812: D/dalvikvm(1505): Not late-enabling CheckJNI (already on)
01-05 14:46:45.964: E/Trace(1505): error opening trace file: No such file or directory (2)
01-05 14:46:47.071: D/gralloc_goldfish(1505): Emulator without GPU emulation detected.
01-05 14:46:49.841: D/AndroidRuntime(1505): Shutting down VM
01-05 14:46:49.841: W/dalvikvm(1505): threadid=1: thread exiting with uncaught exception (group=0xb2f93288)
01-05 14:46:49.854: E/AndroidRuntime(1505): FATAL EXCEPTION: main
01-05 14:46:49.854: E/AndroidRuntime(1505): java.lang.NullPointerException
01-05 14:46:49.854: E/AndroidRuntime(1505):     at be.howest.mad.lab16.oef1.CursorLoaderActivity.onLoadFinished(CursorLoaderActivity.java:50)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at be.howest.mad.lab16.oef1.CursorLoaderActivity.onLoadFinished(CursorLoaderActivity.java:1)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at android.app.LoaderManagerImpl$LoaderInfo.callOnLoadFinished(LoaderManager.java:482)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at android.app.LoaderManagerImpl$LoaderInfo.onLoadComplete(LoaderManager.java:450)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at android.content.Loader.deliverResult(Loader.java:143)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at android.content.CursorLoader.deliverResult(CursorLoader.java:113)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at android.content.CursorLoader.deliverResult(CursorLoader.java:43)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at android.content.AsyncTaskLoader.dispatchOnLoadComplete(AsyncTaskLoader.java:254)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at android.content.AsyncTaskLoader$LoadTask.onPostExecute(AsyncTaskLoader.java:91)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at android.os.AsyncTask.finish(AsyncTask.java:631)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at android.os.AsyncTask.access$600(AsyncTask.java:177)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at android.os.Handler.dispatchMessage(Handler.java:99)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at android.os.Looper.loop(Looper.java:137)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at android.app.ActivityThread.main(ActivityThread.java:4745)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at java.lang.reflect.Method.invokeNative(Native Method)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at java.lang.reflect.Method.invoke(Method.java:511)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
01-05 14:46:49.854: E/AndroidRuntime(1505):     at dalvik.system.NativeStart.main(Native Method)

CursorLoaderActivity.java：

package be.howest.mad.lab16.oef1;

import android.os.Bundle;
import android.provider.ContactsContract.Contacts;
import android.widget.SimpleCursorAdapter;
import android.app.ListActivity;
import android.app.LoaderManager.LoaderCallbacks;
import android.content.CursorLoader;
import android.content.Loader;
import android.database.Cursor;

public class CursorLoaderActivity extends ListActivity implements LoaderCallbacks<Cursor> {

private static final int CONTACTS_LOADER = 0;
private SimpleCursorAdapter adapter;



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    String[] from = new String[] { Contacts.DISPLAY_NAME };
    int[] to = new int[] { android.R.id.text1 };
    SimpleCursorAdapter adapter =  new SimpleCursorAdapter(this, android.R.layout.simple_list_item_1, null, from, to, 0);
    setListAdapter(adapter);

    getLoaderManager().initLoader(CONTACTS_LOADER, null, this); 
}

private static String[] projection = new String[]{
Contacts._ID,
Contacts.DISPLAY_NAME,
}; 



@Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
    if(id == CONTACTS_LOADER) {
        CursorLoader cursorLoader = new CursorLoader(this, Contacts.CONTENT_URI,projection, null, null, null);
            return cursorLoader;
    }
    return null;

}

@Override
public void onLoadFinished(Loader<Cursor> arg0, Cursor arg1) {
    adapter.swapCursor(arg1);
}

@Override
public void onLoaderReset(Loader<Cursor> arg0) {
    adapter.swapCursor(null);
}
}

清单：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="be.howest.mad.lab16.oef1"
android:versionCode="1"
android:versionName="1.0"  >

<uses-sdk
    android:minSdkVersion="15"
    android:targetSdkVersion="16" />

<uses-permission android:name="android.permission.READ_CONTACTS"/>



<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name="be.howest.mad.lab16.oef1.CursorLoaderActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

</application>

</manifest>

有谁知道如何解决这个问题？谢谢！

Answer 1

修正：onCreate方法存在问题。

adapter = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_1,
    null, from, to, 0);

错误打开跟踪文件没有这样的文件或目录（2）

1 个答案: