我有一个带有列表视图和 TextEdit 的活动，用于在该列表视图中进行搜索，当我开始该活动时，所有项目都已加载，但是当我尝试在 EditText 中键入任何单词时，会出现 NullPointerException。
04-06 19:35:23.249: E/AndroidRuntime(8354): FATAL EXCEPTION: main
04-06 19:35:23.249: E/AndroidRuntime(8354): java.lang.NullPointerException
04-06 19:35:23.249: E/AndroidRuntime(8354): at android.widget.SimpleAdapter.getCount(SimpleAdapter.java:93)
04-06 19:35:23.249: E/AndroidRuntime(8354): at android.widget.AdapterView.checkFocus(AdapterView.java:689)
04-06 19:35:23.249: E/AndroidRuntime(8354): at android.widget.AdapterView$AdapterDataSetObserver.onInvalidated(AdapterView.java:812)
04-06 19:35:23.249: E/AndroidRuntime(8354): at android.database.DataSetObservable.notifyInvalidated(DataSetObservable.java:43)
04-06 19:35:23.249: E/AndroidRuntime(8354): at android.widget.BaseAdapter.notifyDataSetInvalidated(BaseAdapter.java:54)
04-06 19:35:23.249: E/AndroidRuntime(8354): at android.widget.SimpleAdapter$SimpleFilter.publishResults(SimpleAdapter.java:383)
04-06 19:35:23.249: E/AndroidRuntime(8354): at android.widget.Filter$ResultsHandler.handleMessage(Filter.java:282)
04-06 19:35:23.249: E/AndroidRuntime(8354): at android.os.Handler.dispatchMessage(Handler.java:99)
04-06 19:35:23.249: E/AndroidRuntime(8354): at android.os.Looper.loop(Looper.java:130)
04-06 19:35:23.249: E/AndroidRuntime(8354): at android.app.ActivityThread.main(ActivityThread.java:3768)
04-06 19:35:23.249: E/AndroidRuntime(8354): at java.lang.reflect.Method.invokeNative(Native Method)
04-06 19:35:23.249: E/AndroidRuntime(8354): at java.lang.reflect.Method.invoke(Method.java:507)
04-06 19:35:23.249: E/AndroidRuntime(8354): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:878)
04-06 19:35:23.249: E/AndroidRuntime(8354): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:636)
04-06 19:35:23.249: E/AndroidRuntime(8354): at dalvik.system.NativeStart.main(Native Method)
这是活动代码：
package com.ferresis;
import java.util.ArrayList;
import java.util.HashMap;
import android.app.ListActivity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import com.ferresis.db.DBAdapter;
import com.ferresis.db.DBAdapter.LocalBinder;
import com.ferresis.db.Productos.ProductosColumns;
public class Act_Productos extends ListActivity {
final String[] from = {ProductosColumns.CODIGO ,ProductosColumns.DESCRIPCION};
final int[] to = new int[] {R.id.rowProdutos_Codigo, R.id.rowProdutos_Descripcion};
DBAdapter dbAdapter;
Boolean mBound;
SimpleAdapter ListAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_productos);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.act__productos, menu);
return true;
}
@Override
protected void onStart() {
super.onStart();
// Enlazamos con el Servicio
Intent intent = new Intent(this, DBAdapter.class);
bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
}
@Override
protected void onStop() {
super.onStop();
// Nos desenlazamos del servicio
if (mBound) {
unbindService(mConnection);
mBound = false;
}
}
private ServiceConnection mConnection = new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName className, IBinder service) {
// Enlazamos con LocalService, casteamos el IBinder y obtenemos así
// la instancia del Servicio
LocalBinder binder = (LocalBinder) service;
dbAdapter = binder.getService();
mBound = true;
loadProductos();
}
@Override
public void onServiceDisconnected(ComponentName arg0) {
mBound = false;
}
};
private void loadProductos() {
ArrayList<Producto> productos = dbAdapter.getAllProductos();
// Fill List with DATA
ArrayList<HashMap<String, String>> HProductos = new ArrayList<HashMap<String, String>>();
for (Producto producto : productos) {
HashMap<String, String> Data = new HashMap<String, String>();
Data.put(ProductosColumns._ID, String.valueOf(producto.getID()));
Data.put(from[0], producto.getCodigo());
Data.put(from[1], producto.getDescripcion());
HProductos.add(Data);
}
ListAdapter = new SimpleAdapter(this, HProductos,
R.layout.row_productos, from, to);
setListAdapter(ListAdapter);
EditText etSearchbox=(EditText)findViewById(R.id.txtProducto_Busqueda);
final ListView lv = getListView();
lv.setTextFilterEnabled(true);
etSearchbox.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) {
// TODO Auto-generated method stub
Act_Productos.this.ListAdapter.getFilter().filter(arg0);
Log.d("Log","p1");
}
@Override
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
int arg3) {
// TODO Auto-generated method stub
}
@Override
public void afterTextChanged(Editable arg0) {
// TODO Auto-generated method stub
}
});
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> myAdapter, View myView, int myItemInt, long mylng) {
//String selectedFromList =(String) ();
Intent returnIntent = new Intent();
String item = "" + lv.getItemAtPosition(myItemInt);
item = item.substring(item.indexOf("=")+1,item.indexOf(","));
returnIntent.putExtra("idProducto",item);
setResult(RESULT_OK,returnIntent);
finish();
}
});
}
}