尝试从Parse加载一个类，但是一旦我启动它，应用程序就会崩溃！
这是代码：
ListView listview;
List<ParseObject> ob;
ProgressDialog mProgressDialog;
ArrayAdapter<String> adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_big_board);
new RemoteDataTask().execute();
}
private class RemoteDataTask extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
mProgressDialog = new ProgressDialog(BigBoard.this);
mProgressDialog.setTitle("Parse.com Simple ListView Tutorial");
mProgressDialog.setMessage("Loading...");
mProgressDialog.setIndeterminate(false);
mProgressDialog.show();
}
@Override
protected Void doInBackground(Void... params) {
// Locate the class table named "Country" in Parse.com
ParseQuery<ParseObject> query = new ParseQuery<ParseObject>(
"Country");
query.orderByDescending("_created_at");
try {
ob = query.find();
} catch (ParseException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result) {
// Locate the listview in listview_main.xml
listview = (ListView) findViewById(R.id.listview);
// Pass the results into an ArrayAdapter
adapter = new ArrayAdapter<String>(BigBoard.this,
R.layout.listview_item);
// Retrieve object "name" from Parse.com database
for (ParseObject country : ob) {
adapter.add((String) country.get("Name"));
}
// Binds the Adapter to the ListView
listview.setAdapter(adapter);
// Close the progressdialog
mProgressDialog.dismiss();
// Capture button clicks on ListView items
listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// Send single item click data to SingleItemView Class
Intent i = new Intent(BigBoard.this,
SingleItemView.class);
// Pass data "name" followed by the position
i.putExtra("name", ob.get(position).getString("name")
.toString());
// Open SingleItemView.java Activity
startActivity(i);
}
});
}
}
这就是我在logcat中获得的：
> 10-22 20:40:18.705 12588-12872/obx.com.futurister E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #3
Process: obx.com.futurister, PID: 12588
java.lang.RuntimeException: An error occurred while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:309)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)
at java.util.concurrent.FutureTask.setException(FutureTask.java:223)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.io.File com.parse.ParsePlugins.getParseDir()' on a null object reference
at com.parse.Parse.getParseDir(Parse.java:315)
at com.parse.ParseCorePlugins.getCurrentUserController(ParseCorePlugins.java:129)
at com.parse.ParseUser.getCurrentUserController(ParseUser.java:55)
at com.parse.ParseUser.getCurrentUserAsync(ParseUser.java:888)
at com.parse.ParseQuery.getUserAsync(ParseQuery.java:938)
at com.parse.ParseQuery$3.call(ParseQuery.java:1196)
at com.parse.ParseQuery$3.call(ParseQuery.java:1193)
at com.parse.ParseQuery.doWithRunningCheck(ParseQuery.java:1132)
at com.parse.ParseQuery.findAsync(ParseQuery.java:1193)
at com.parse.ParseQuery.findInBackground(ParseQuery.java:1161)
at com.parse.ParseQuery.find(ParseQuery.java:981)
at obx.com.futurister.BigBoard$RemoteDataTask.doInBackground(BigBoard.java:66)
at obx.com.futurister.BigBoard$RemoteDataTask.doInBackground(BigBoard.java:44)
at android.os.AsyncTask$2.call(AsyncTask.java:295)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
10-22 20:40:18.857 12588-12619/obx.com.futurister E/Surface﹕ getSlotFromBufferLocked: unknown buffer: 0xb3a1fb90
10-22 20:40:18.955 12588-12619/obx.com.futurister E/Surface﹕ getSlotFromBufferLocked: unknown buffer: 0xa96acbb0
10-22 20:40:18.996 12588-12588/obx.com.futurister E/WindowManager﹕ android.view.WindowLeaked: Activity obx.com.futurister.BigBoard has leaked window com.android.internal.policy.PhoneWindow$DecorView{a0f50b2 V.E...... R......D 0,0-1026,538} that was originally added here
at android.view.ViewRootImpl.<init>(ViewRootImpl.java:368)
at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:299)
at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:85)
at android.app.Dialog.show(Dialog.java:319)
at obx.com.futurister.BigBoard$RemoteDataTask.onPreExecute(BigBoard.java:56)
at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:604)
at android.os.AsyncTask.execute(AsyncTask.java:551)
at obx.com.futurister.BigBoard.onCreate(BigBoard.java:40)
at android.app.Activity.performCreate(Activity.java:6237)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
用doInBackground()方法猜测它的问题？我错过了什么吗？请帮忙，谢谢
答案 0 :(得分：15)
根据你的评论，我猜你没有初始化Parse。 http://docs.parseplatform.org/android/guide/#local-datastore
public class App extends Application {
@Override
public void onCreate() {
super.onCreate();
// Enable Local Datastore.
Parse.enableLocalDatastore(this);
// Register any ParseObject subclass. Must be done before calling Parse.initialize()
ParseObject.registerSubclass(YourClass.class);
Parse.initialize(this, "APPLICATION_ID", "CLIENT_KEY");
}
}
确保将App类添加到清单
答案 1 :(得分：-1)
您需要在清单中分配您的App文件 打开清单文件，并将此代码添加到应用程序标签第一行的清单文件中 android：name =“。App”
祝你编程好运