【Android笔记】ContextMenu上下文菜单

ContextMenu上下文菜单

1.ContextMenu菜单的组成部分

标题及标题图标

菜单内容

菜单内容的点击响应事件

2.ContextMenu与OptionMenu的区别

OptionMenu对应的是activity，一个activity只能拥有一个选项菜单

ContextMenu对应的是View，每个View都可以设置上下文菜单

3.ContextMenu的创建方法

首先给View注册上下文菜单registerForContextMenu()

添加上下文菜单内容onCreateContextMenu()

设置菜单点击后响应事件onContextItemSelected()

实例一：动态添加

package com.example.demo16;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

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

/**
* 设置ListView显示内容
*/
private void showListView(){
ListView listView = (ListView) findViewById(R.id.listView);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, getData());
listView.setAdapter(adapter);
this.registerForContextMenu(listView);
}

@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
super.onCreateContextMenu(menu, v, menuInfo);
//设置Menu显示内容
menu.setHeaderTitle("文件操作");
menu.setHeaderIcon(R.drawable.file);
menu.add(1, 100, 1, "复制");
menu.add(1, 101, 1, "剪切");
menu.add(1, 102, 1, "粘贴");
}

@Override
public boolean onContextItemSelected(MenuItem item) {
switch (item.getItemId()) {
case 100:
Toast.makeText(MainActivity.this, "点击了复制", Toast.LENGTH_SHORT).show();
break;
case 101:
Toast.makeText(MainActivity.this, "点击了剪切", Toast.LENGTH_SHORT).show();
break;
case 102:
Toast.makeText(MainActivity.this, "点击了粘贴", Toast.LENGTH_SHORT).show();
break;
}
return super.onContextItemSelected(item);
}

/**
* 构造ListView显示的数据
* @return
*/
private ArrayList<String> getData(){
ArrayList<String> list = new ArrayList<String>();
for(int i=0; i<5; ++i) {
list.add("文件" + i);
}
return list;
}
}

运行效果：

实例二：使用xml添加

1.在资源目录res下创建menu资源文件夹

2.在menu文件夹下创建main.xml文件

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:id="@+id/action_item1"
android:orderInCategory="100"
android:showAsAction="never"
android:title="复制"/>

<item
android:id="@+id/action_item2"
android:orderInCategory="101"
android:showAsAction="never"
android:title="剪切"/>

<item
android:id="@+id/action_item3"
android:orderInCategory="102"
android:showAsAction="never"
android:title="粘贴"/>
</menu>

3.创建菜单

package com.example.demo16;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

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

/**
* 设置ListView显示内容
*/
private void showListView(){
ListView listView = (ListView) findViewById(R.id.listView);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, getData());
listView.setAdapter(adapter);
//注册上下文菜单
this.registerForContextMenu(listView);
}

@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
super.onCreateContextMenu(menu, v, menuInfo);
//设置Menu显示内容
menu.setHeaderTitle("文件操作");
menu.setHeaderIcon(R.drawable.file);
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main, menu);
}

@Override
public boolean onContextItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_item1:
Toast.makeText(MainActivity.this, "点击了复制", Toast.LENGTH_SHORT).show();
break;
case R.id.action_item2:
Toast.makeText(MainActivity.this, "点击了剪切", Toast.LENGTH_SHORT).show();
break;
case R.id.action_item3:
Toast.makeText(MainActivity.this, "点击了粘贴", Toast.LENGTH_SHORT).show();
break;
}
return super.onContextItemSelected(item);
}

/**
* 构造ListView显示的数据
* @return
*/
private ArrayList<String> getData(){
ArrayList<String> list = new ArrayList<String>();
for(int i=0; i<5; ++i) {
list.add("文件" + i);
}
return list;
}
}

效果如上例