Bei der Methode "listview.setOnItemLongClickListener" ist ein Fehler in der Ansicht "return view" aufgetreten. Der Fehler sagt, dass ein Wert von einer Methode mit dem ungültigen Ergebnistyp nicht zurückgegeben werden kann. Ich versuche, einen Warndialog zu erstellen, in dem der Benutzer benachrichtigt wird, ob er löschen möchte.Fehler im Dialogfeld "Warnung"
package com.example.user.swen;
import android.app.AlertDialog;
import android.app.ListActivity;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.text.Html;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
import com.example.user.swen.DB.RecordsDataSource;
import com.example.user.swen.Model.Records;
public class Record extends ListActivity {
public Button NewButton;
public RecordsDataSource Recordsdatasource;
ArrayAdapter<Records> RecordAdapter;
List<Records> records;
ListView listview;
Records selectedRecord;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_record);
Addrecords();
//Referencing the Database
Recordsdatasource = new RecordsDataSource(this);
Recordsdatasource.open();
LayoutInflater inflater = LayoutInflater.from(Record.this);
View view = inflater.inflate(R.layout.activity_record, null);
//set the listView to use the custom List Adapter
records = (List<Records>) Recordsdatasource.getAll();
RecordAdapter = new RecordAdapter(this, 0, (ArrayList<Records>) records);
listview = (ListView) findViewById(android.R.id.list);
listview.setAdapter(RecordAdapter);
listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
selectedRecord = records.get(position);
AlertDialog.Builder a_builder = new AlertDialog.Builder(Record.this);
a_builder.setMessage("Duty: " + selectedRecord.getType())
.setCancelable(false)
.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
}
});
AlertDialog alert = a_builder.create();
alert.setTitle(Html.fromHtml("<font color='#08ae9e'>Information</font>"));
alert.show();
}
});
listview.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
selectedRecord = records.get(position);
AlertDialog.Builder a_builder = new AlertDialog.Builder(Record.this);
a_builder.setMessage("Are you sure you want to delete?")
.setCancelable(false)
.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
deleteItem(selectedRecord);
}
})
.setNegativeButton("No", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
AlertDialog alert = a_builder.create();
alert.setTitle(Html.fromHtml("<font color='#08ae9e'>Alert!!</font>"));
alert.show();
return true;
}
});
return view;
}
public void Addrecords() {
NewButton = (Button) findViewById(R.id.NewButton);
NewButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent addrecords = new Intent(Record.this, NewRecord.class);
startActivity(addrecords);
}
});
}
public static void showToast(Context context, String text) {
Toast.makeText(context, text, Toast.LENGTH_LONG).show();
}
private void deleteItem(Records selectedRecord) {
Recordsdatasource.removeRecords(selectedRecord);
showToast(this, "Usage deleted");
RecordAdapter.notifyDataSetChanged();
RecordAdapter.notifyDataSetInvalidated();
refreshDisplay();
}
private void refreshDisplay() {
records = Recordsdatasource.getAll();
RecordAdapter.clear();
RecordAdapter.addAll(records);
}
}