选项菜单-上下文菜单

菜单
分类
选项菜单 OptionMenu
按menu键触发
事件源是Activity
上下文菜单 ContextMenu
长按组件时触发
子菜单 SubMenu
addSubMenu( )添加子菜单
用法
选项菜单
创建：重写onCreatOptionsMenu(Menu menu)
在代码里给menu添加MenuItem
纯java代码
menu.add( )
加载menu资源文件
1-获得Menu加载器
MenuInflater m=getMenuInflater( );
2-加载Menu资源文件
m.inflat(Menu资源文件的id,menu当前菜单)
以上两种加载方式可以并存
回调：重写boolean onOptionsItemSelected(MenuItem item)
上下文菜单
Activity 是OnCreateContextMenuListener的实现类
创建：组件.setOnCreateContextMenuListener（this）
在代码里添加MenuItem，方式同 选项菜单
响应：重写Activity的boolean onContextItemSelected(MenuItem item)
与LongClick监听器的关系
LongClick监听器的优先级高
boolean onLongClick(View v)的返回值决定后续的监听器能否被处理

package com.hanqi.testapp2;

import android.app.Activity;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.SubMenu;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class TestActivity3 extends Activity {

    Button bt_1;
    Button bt_2;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_test3);

        bt_1=(Button)findViewById(R.id.bt_1);
        bt_2=(Button)findViewById(R.id.bt_2);

        //给组件添加上下菜单 Activity是OnCreateContextMenuListener的实现类
        bt_2.setOnCreateContextMenuListener(
                this
        );


        //添加长按监听器
//        bt_2.setOnLongClickListener(new View.OnLongClickListener() {
//            @Override
//            public boolean onLongClick(View v) {
//
//                Toast.makeText(TestActivity3.this, "按钮被长按了", Toast.LENGTH_SHORT).show();
//
//                return true;//后面不再处理
//            }
//        });

        //点击
        bt_1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Toast.makeText(TestActivity3.this, "按钮被点击了", Toast.LENGTH_SHORT).show();
            }
        });

        //长按
        bt_1.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {

                Toast.makeText(TestActivity3.this, "按钮被长按了", Toast.LENGTH_SHORT).show();

                //事件是否已经被消费
                return true;
            }
        });


    }

    //重写创建上下文菜单的方法

    @Override
    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
        super.onCreateContextMenu(menu, v, menuInfo);

        //java
        menu.add(1,0,1,"字体大小");
        menu.add(1, 1, 2, "背景颜色");

        SubMenu sm=menu.addSubMenu(1, 2, 3, "子菜单");

        sm.add(2,21,0,"子菜单1");
        sm.add(2,22,1,"子菜单2");

        //加载文件
        MenuInflater m=getMenuInflater();
        m.inflate(R.menu.test3_menu,menu);
    }

    @Override
    public boolean onContextItemSelected(MenuItem item) {

        Toast.makeText(TestActivity3.this, "上下文菜单的标题title="+item.getTitle(), Toast.LENGTH_SHORT).show();

        return super.onContextItemSelected(item);
    }

    //给activity 添加选项菜单
    //重写
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        //添加菜单
//        menu.add(1,1,0,"添加");
//        menu.add(1,2,2,"修改");
//        menu.add(1,3,1,"删除");

        //加载菜单文件方式
        //1-获得菜单加载器
        MenuInflater m=getMenuInflater();

        //2-加载菜单文件 1)菜单文件 2)当前菜单
        m.inflate(R.menu.test3_menu,menu);

        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

        Toast.makeText(TestActivity3.this, "菜单项的id="+item.getItemId()+"菜单项的title"+item.getTitle(), Toast.LENGTH_SHORT).show();

        //怎么判断菜单文件里的菜单哪个被选中了

        if(item.getItemId()==R.id.me_1)
        {
            Toast.makeText(TestActivity3.this, "执行删除动作", Toast.LENGTH_SHORT).show();
        }
        else if (item.getItemId()==R.id.me_2)
        {
            Toast.makeText(TestActivity3.this, "执行修改动作", Toast.LENGTH_SHORT).show();
        }

        return super.onOptionsItemSelected(item);
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.hanqi.testapp2.TestActivity3"
    android:orientation="vertical">

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="拨打电话"
        android:id="@+id/bt_1" />

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="上下文菜单按钮"
        android:id="@+id/bt_2" />

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:id="@+id/me_1" android:title="删除"/>
    <item android:id="@+id/me_2" android:title="修改"/>
</menu>