我的应用程序包含2个autoCompletetextview（ACT），当我点击列表中的一个项目时显示。我收到了这个错误。我试图解决它，但从昨天起，我仍然无法解决它。我真的希望你能帮助我或提出任何解决这个问题的建议。
FindMEPlace.java
public class FindMePlace extends Activity {
public static UkmRoute selectedPath = null;
private AutoCompleteDbAdapter mDbHelper;
public AutoCompleteTextView fromLocation, toDestination;
Button search;
ArrayAdapter<String> arrayAdapter1 = null;
ArrayAdapter<String> arrayAdapter2 = null;
final ArrayList<String> results = new ArrayList<String>();
final ArrayList<String> results_id = new ArrayList<String>();
final ArrayList<String> results2 = new ArrayList<String>();
final ArrayList<String> results_id2 = new ArrayList<String>();
final AutoCompleteDbAdapter dbHelper = new AutoCompleteDbAdapter(this);
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.find_me_place);
dbHelper.open();
//link with the layout items
fromLocation = (AutoCompleteTextView) findViewById(R.id.locationTxt);
toDestination = (AutoCompleteTextView) findViewById(R.id.destinationTxt);
search = (Button) findViewById(R.id.button1);
//---------------------------------------------------------------------
//---------------------------------------------------------------------
//---------------------LOCATION--------------------------------------
// Reading location
Log.d("Reading", "Reading all location..");
List<Location> location = dbHelper.getAllLocation();
for (Location k : location) {
results.add(k.getLocationUkm());
results_id.add(k.getID());
}
arrayAdapter1 = new ArrayAdapter<String>(FindMePlace.this,R.layout.list_item, R.id.textView1, results);
fromLocation.setAdapter(arrayAdapter1);
fromLocation.setOnItemClickListener(new OnItemClickListener(){
public void onItemClick(AdapterView<?> listView, View view,
int position, long id) {
// When clicked, show a toast with the TextView text
Toast.makeText(getApplicationContext(), ((TextView) view).getText(),
Toast.LENGTH_SHORT).show();
Log.d("test", "position:" + position);
Log.d("test", "actualname:" + dbHelper.getSingleLocation(arrayAdapter1.getItem(position)).getLocationUkm());
String fromLoc = dbHelper.getSingleLocation(arrayAdapter1.getItem(position)).getID();
String name = arrayAdapter1.getItem(position);
fromLocation.setText(fromLoc);
}
});
错误点在这里
Log.d("test", "actualname:" + dbHelper.getSingleLocation(arrayAdapter1.getItem(position)).getLocationUkm());
AutoCompleteDbAdapter.java
public void addLocation(Location location) {
mDb = mDbHelper.getReadableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_LOCATIONID, location.getID()); // ID
values.put(KEY_LOCATION_NAME, location.getLocationUkm()); // from
// Inserting Row
mDb.insert(DATABASE_NAME, null, values);
mDb.close(); // Closing database connection
}
// Getting single Poi
public Location getSingleLocation(String id_location) {
mDb = mDbHelper.getReadableDatabase();
Cursor cursor = mDb.query(TABLE_LOCATION,
new String[] {KEY_LOCATIONID, KEY_LOCATION_NAME},
KEY_LOCATIONID + "=?",
new String[] {String.valueOf( id_location)}, null, null, null, null);
if (cursor != null)
cursor.moveToFirst();
Location location = new Location(cursor.getString(0),
cursor.getString(1));
return location;
}
// Getting single UKMRoute by From
public Location getLocationName(String Location_name) {
mDb = mDbHelper.getReadableDatabase();
Cursor cursor = mDb.query(TABLE_LOCATION,
new String[] {KEY_LOCATIONID, KEY_LOCATION_NAME},
KEY_LOCATION_NAME + "=?",
new String[] { String.valueOf(Location_name) }, null, null, null, null);
if (cursor != null)
cursor.moveToFirst();
Location location = new Location(cursor.getString(0),cursor.getString(1));
return location;
}
// Getting all Poi
public List<Location> getAllLocation() {
List<Location> locationList = new ArrayList<Location>();
//Select All Query
String selectQuery = "SELECT * FROM " + TABLE_LOCATION;
mDb = mDbHelper.getReadableDatabase();
Cursor cursor = mDb.rawQuery(selectQuery, null);
//looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
Location poi = new Location();
poi.setID(cursor.getString(0));
poi.setLocationUkm(cursor.getString(1));
locationList.add(poi);
} while (cursor.moveToNext());
}
//sorting list
Collections.sort(locationList,new Comparator<Location>() {
public int compare(Location poi, Location otherPoi) {
return poi.getID().compareTo(otherPoi.getID());
}
});
// return Poi list
mDb.close();
return locationList;
}
另一个错误点在这里
Location location = new Location(cursor.getString(0),cursor.getString(1)）;
07-05 11:32:58.183: E/AndroidRuntime(30311): FATAL EXCEPTION: main
07-05 11:32:58.183: E/AndroidRuntime(30311): android.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0
07-05 11:32:58.183: E/AndroidRuntime(30311): at android.database.AbstractCursor.checkPosition(AbstractCursor.java:580)
07-05 11:32:58.183: E/AndroidRuntime(30311): at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:214)
07-05 11:32:58.183: E/AndroidRuntime(30311): at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:41)
07-05 11:32:58.183: E/AndroidRuntime(30311): at com.example.series1.AutoCompleteDbAdapter.getSingleLocation(AutoCompleteDbAdapter.java:452)
07-05 11:32:58.183: E/AndroidRuntime(30311): at com.example.series1.FindMePlace$1.onItemClick(FindMePlace.java:73)
07-05 11:32:58.183: E/AndroidRuntime(30311): at android.widget.AutoCompleteTextView.performCompletion(AutoCompleteTextView.java:952)
07-05 11:32:58.183: E/AndroidRuntime(30311): at android.widget.AutoCompleteTextView.access$1400(AutoCompleteTextView.java:92)
07-05 11:32:58.183: E/AndroidRuntime(30311): at android.widget.AutoCompleteTextView$DropDownItemClickListener.onItemClick(AutoCompleteTextView.java:1489)
07-05 11:32:58.183: E/AndroidRuntime(30311): at android.widget.AdapterView.performItemClick(AdapterView.java:284)
07-05 11:32:58.183: E/AndroidRuntime(30311): at android.widget.ListView.performItemClick(ListView.java:3513)
07-05 11:32:58.183: E/AndroidRuntime(30311): at android.widget.AbsListView$PerformClick.run(AbsListView.java:1812)
07-05 11:32:58.183: E/AndroidRuntime(30311): at android.os.Handler.handleCallback(Handler.java:587)
07-05 11:32:58.183: E/AndroidRuntime(30311): at android.os.Handler.dispatchMessage(Handler.java:92)
07-05 11:32:58.183: E/AndroidRuntime(30311): at android.os.Looper.loop(Looper.java:123)
07-05 11:32:58.183: E/AndroidRuntime(30311): at android.app.ActivityThread.main(ActivityThread.java:3683)
07-05 11:32:58.183: E/AndroidRuntime(30311): at java.lang.reflect.Method.invokeNative(Native Method)
07-05 11:32:58.183: E/AndroidRuntime(30311): at java.lang.reflect.Method.invoke(Method.java:507)
07-05 11:32:58.183: E/AndroidRuntime(30311): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
07-05 11:32:58.183: E/AndroidRuntime(30311): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
07-05 11:32:58.183: E/AndroidRuntime(30311): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：1)
这段代码错了（除了缺少括号，我还要惩罚你）：
if (cursor != null)
cursor.moveToFirst();
光标不是null的事实 NOT 意味着它保存了要获取的任何数据。因此查询可以成功（并且游标不为空），但同时该查询的结果可能为零。因此，在开始阅读结果之前，您需要确保收集数据。最简单的方法是检查moveToFirst()是否返回true或致电getCount()以获取结果数量。见docs on Cursor
答案 1 :(得分：0)
这可以帮助你..
我认为你没有初学mDbhelper;
这样做：
AutoCompleteDbAdapter mDbHelper = new AutoCompleteDbAdapter(context);
和if (cursor != null)错误
答案 2 :(得分：-1)
我知道它已经很晚但我会说是否有其他人有这个问题。 试试这段代码：
public boolean isempty(String tablename)
{
Cursor cur2 = database.rawQuery("SELECT COUNT(*) FROM "
+ tablename , null);
if(cur2 != null)
{
Log.e("DATA", "CURSOR NOT NULL");
if(cur2.moveToFirst())
{
Log.e("DATA", "CURSOR MOVE TO FIRST");
if(cur2.getInt(0) != 0)
{
Log.e("DATA", "CURSOR HAS INDEX");
if(cur2.isClosed())
{
cur2.close();
return false;
}
else
{
cur2.close();
return false;
}
}
else
{
Log.e("DATA", "CURSOR DON'T HAVE INDEX");
if(cur2.isClosed())
{
return true;
}
else
{
cur2.close();
return true;
}
}
}
else
{
Log.e("DATA", "CURSOR MOVE TO FIRST IS NULL");
if(cur2.isClosed())
return true;
else
{
cur2.close();
return true;
}
}
}
else
{
Log.e("DATA", "CURSOR IS NULL");
return true;
}
}