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 adapter = new ArrayAdapter(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 getData(){

ArrayList list = new ArrayList();

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

android:id="@+id/action_item1"

android:orderInCategory="100"

android:showAsAction="never"

android:title="复制"/>

android:id="@+id/action_item2"

android:orderInCategory="101"

android:showAsAction="never"

android:title="剪切"/>

android:id="@+id/action_item3"

android:orderInCategory="102"

android:showAsAction="never"

android:title="粘贴"/>

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 adapter = new ArrayAdapter(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 getData(){

ArrayList list = new ArrayList();

for(int i=0; i<5; ++i) {

list.add("文件" + i);

}

return list;

}

}

效果如上例