android 上下文菜单详解

本文使用xml来创建上下文菜单

<?xml version="1.0" encoding="utf-8"?>

<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <item

            android:id="@+id/add"

            android:title="添加"

            android:orderInCategory="4"

            />

    <item

            android:id="@+id/delete"

            android:title="删除"

            android:orderInCategory="1"

            />

    <item

            android:id="@+id/query"

            android:title="查询"

            android:orderInCategory="2"

            />

    <item

            android:id="@+id/update"

            android:title="更新"

            android:orderInCategory="3"

            />

</menu>

orderInCategory属性为排列顺序

MyActivity的布局：

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

              android:orientation="vertical"

              android:layout_width="fill_parent"

              android:layout_height="fill_parent"

        >

    <Button

            android:id="@+id/btn"

            android:layout_width="match_parent"

            android:layout_height="wrap_content"

            android:text="弹出上下文菜单"

            />

</LinearLayout>

MyActivity.java

package com.example.contextMenuTest;

import android.app.Activity;

import android.os.Bundle;

import android.view.ContextMenu;

import android.view.MenuItem;

import android.view.View;

import android.widget.Button;

import android.widget.Toast;

public class MyActivity extends Activity {

   private Button button;

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        button = (Button) findViewById(R.id.btn);

        //为按钮注册contextMenu，当你长按按钮的时候就会调用onCreateContextMenu方法

        registerForContextMenu(button);

    }

    /**

     * 注意：每次长按注册了contextMenu的控件，都会重新调用该方法

     */

    @Override

    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {

        System.out.println("com.example.contextMenuTest.MyActivity.onCreateContextMenu");

        getMenuInflater().inflate(R.menu.basic_main, menu);

        //设置标题栏的图标

        menu.setHeaderIcon(R.drawable.ic_launcher);

        //设置标题栏的文字

        menu.setHeaderTitle("请选择操作");

    }

    @Override

    public boolean onContextItemSelected(MenuItem item) {

        switch (item.getItemId()) {

            case R.id.add:

                Toast.makeText(this, "你点击了添加！", 1).show();

                break;

            case R.id.delete:

                Toast.makeText(this, "你点击了删除！", 1).show();

                break;

            case R.id.update:

                Toast.makeText(this, "你点击了修改！", 1).show();

                break;

            case R.id.query:

                Toast.makeText(this, "你点击了查询！", 1).show();

                break;

        }

        return true;

    }

}