Android UI教程 - Android选项菜单

以下代码显示了如何以在用户按下Android设备上的MENU键时显示选项菜单。

例子

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Please enter some text" />

    <EditText
        android:id="@+id/txtText1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />

    <Button
        android:id="@+id/btnSave"
        android:text="Save"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:onClick="onClickSave" />

    <Button
        android:id="@+id/btnLoad"
        android:text="Load"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:onClick="onClickLoad" />

</LinearLayout>

将以下语句以粗体形式添加到MenusActivity.java文件中:

package com.java2s.myapplication3.app;
/*  w w  w.j a  v a  2  s.  co m*/


import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

public class MainActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        super.onCreateOptionsMenu(menu);
        CreateMenu(menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item)
    {
        return MenuChoice(item);
    }
    private void CreateMenu(Menu menu)
    {
        MenuItem mnu1 = menu.add(0, 0, 0, "Item 1");
        {
            mnu1.setAlphabeticShortcut( "a");
            mnu1.setIcon(R.drawable.ic_launcher);
        }
        MenuItem mnu2 = menu.add(0, 1, 1, "Item 2");
        {
            mnu2.setAlphabeticShortcut( "b");
            mnu2.setIcon(R.drawable.ic_launcher);
        }
        MenuItem mnu3 = menu.add(0, 2, 2, "Item 3");
        {
            mnu3.setAlphabeticShortcut( "c");
            mnu3.setIcon(R.drawable.ic_launcher);
        }
        MenuItem mnu4 = menu.add(0, 3, 3, "Item 4");
        {
            mnu4.setAlphabeticShortcut( "d");
        }
        menu.add(0, 4, 4, "Item 5");
        menu.add(0, 5, 5, "Item 6");
        menu.add(0, 6, 6, "Item 7");
    }

    private boolean MenuChoice(MenuItem item)
    {
        switch (item.getItemId()) {
            case 0:
                Toast.makeText (this, "You clicked on Item 1",
                        Toast.LENGTH_LONG).show();
                return true;
            case 1:
                Toast.makeText (this, "You clicked on Item 2",
                        Toast.LENGTH_LONG).show();
                return true;
            case 2:
                Toast.makeText (this, "You clicked on Item 3",
                        Toast.LENGTH_LONG).show();
                return true;
            case 3:
                Toast.makeText (this, "You clicked on Item 4",
                        Toast.LENGTH_LONG).show();
                return true;
            case 4:
                Toast.makeText (this, "You clicked on Item 5",
                        Toast.LENGTH_LONG).show();
                return true;
            case 5:
                Toast.makeText (this, "You clicked on Item 6",
                        Toast.LENGTH_LONG).show();
                return true;
            case 6:
                Toast.makeText (this, "You clicked on Item 7",
                        Toast.LENGTH_LONG).show();
                return true;
        }
        return false;
    }
}