Question

我正在尝试使用此MenuItem加载不同的活动，当我单击menuitem（特别是 - 帮助）时，User1Tap.class没有加载正确的活动（它将我带到AddEditCountry.class）

import android.os.AsyncTask;
import android.os.Bundle;
import android.app.AlertDialog;
import android.app.ListActivity;
import android.content.DialogInterface;
import android.content.Intent;
import android.database.Cursor;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.CursorAdapter;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.AdapterView.OnItemClickListener;

public class CountryList extends ListActivity {

 public static final String ROW_ID = "row_id";
 private ListView conListView;
 private CursorAdapter conAdapter;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    conListView=getListView();
    conListView.setOnItemClickListener(viewConListener);

    // map each name to a TextView
    String[] from = new String[] { "name" };
    int[] to = new int[] { R.id.countryTextView };
    conAdapter = new SimpleCursorAdapter(CountryList.this, R.layout.country_list, null, from, to);
    setListAdapter(conAdapter); // set adapter
}


@Override
protected void onResume() 
{
   super.onResume();  
   new GetContacts().execute((Object[]) null);
 } 


@Override
protected void onStop() 
{
   Cursor cursor = conAdapter.getCursor();

   if (cursor != null) 
      cursor.deactivate();

   conAdapter.changeCursor(null);
   super.onStop();
}    


private class GetContacts extends AsyncTask<Object, Object, Cursor> 
{
   DatabaseConnector dbConnector = new DatabaseConnector(CountryList.this);

   @Override
   protected Cursor doInBackground(Object... params)
   {
      dbConnector.open();
      return dbConnector.getAllContacts(); 
   } 

   @Override
   protected void onPostExecute(Cursor result)
   {
      conAdapter.changeCursor(result); // set the adapter's Cursor
      dbConnector.close();
   } 
} 

@Override
public boolean onCreateOptionsMenu(Menu menu) 
   {
      super.onCreateOptionsMenu(menu);
      MenuInflater inflater = getMenuInflater();
      inflater.inflate(R.menu.country_menu, menu);
      return true;
   }

   @Override
   public boolean onOptionsItemSelected(MenuItem item) 
   {
      switch (item.getItemId())
      {
         case R.id.editItem:
            Intent addEditContact =
               new Intent(this, AddEditCountry.class);

            addEditContact.putExtra(CountryList.ROW_ID, rowID);
            addEditContact.putExtra("name", nameTv.getText());
            addEditContact.putExtra("cap", capTv.getText());
            addEditContact.putExtra("code", codeTv.getText());
            startActivity(addEditContact); 
            return true;

         case R.id.deleteItem:
            deleteContact();
            return true;

         case R.id.help:
             Intent i = new Intent(ViewCountry.this, User1Tap.class);
             CountryList.this.startActivity(i);
                                  this.finish();
                return true;

         default:
            return super.onOptionsItemSelected(item);
      } 
   }

   private void deleteContact()
   {

      AlertDialog.Builder alert = new AlertDialog.Builder(ViewCountry.this);

      alert.setTitle(R.string.confirmTitle); 
      alert.setMessage(R.string.confirmMessage); 

      alert.setPositiveButton(R.string.delete_btn,
         new DialogInterface.OnClickListener()
         {
            public void onClick(DialogInterface dialog, int button)
            {
               final DatabaseConnector dbConnector = 
                  new DatabaseConnector(ViewCountry.this);

               AsyncTask<Long, Object, Object> deleteTask =
                  new AsyncTask<Long, Object, Object>()
                  {
                     @Override
                     protected Object doInBackground(Long... params)
                     {
                        dbConnector.deleteContact(params[0]); 
                        return null;
                     } 

                     @Override
                     protected void onPostExecute(Object result)
                     {
                        finish(); 
                     }
                  };

               deleteTask.execute(new Long[] { rowID });               
            }
         }
      );

      alert.setNegativeButton(R.string.cancel_btn, null).show();
   }
}

country_menu.xml：

<?xml version="1.0" encoding="utf-8"?>
    <menu xmlns:android="schemas.android.com/apk/res/android">; 
        <item android:id="@+id/addCountryItem"
             android:title="@string/add_menu"
             android:titleCondensed="@string/add_menu"
             android:showAsAction="always"
             android:alphabeticShortcut="e"/>
        <item android:id="@+id/help"
             android:title="@string/help"
             android:titleCondensed="@string/help"
             android:alphabeticShortcut="e"/> 
    </menu>

Answer 1

试试这个：

case R.id.help:
    Intent i = new Intent(this, User1Tap.class);
    startActivity(i);
    finish();
    return true;

Answer 2

在你的oncreate（）方法中调用方法setcontentview（）... 我猜它从那里失踪了...... 试试它是否有效

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
conListView=getListView();
conListView.setOnItemClickListener(viewConListener);

//like this
setcontentview(R.layout.yourlayout);

String[] from = new String[] { "name" };
int[] to = new int[] { R.id.countryTextView };
conAdapter = new SimpleCursorAdapter(CountryList.this, R.layout.country_list, null, from, to);
setListAdapter(conAdapter); // set adapter
}

如何使用此菜单项加载不同的活动

2 个答案: