ContextMenu使用实例

分手后的思念是犯贱 2022-04-23 10:40 239阅读 0赞

Android除了可以通过菜单键弹出OptionsMenu外，还可以长按某个控件来弹出ContextMenu。比如EditeText就可以通过长按来弹出拥有“cut”,"copy","paste"等项的ContextMenu。

ContextMenu和OptionsMenu相比主要有以下区别：

1，ContextMenu必须通过Activity的 [registerForContextMenu(View)][registerForContextMenu_View]来进行注册，而OptionsMenu不用。

2，ContextMenu不支持icon,而OptionsMenu支持。

3，ContextMenu可以有头，可以通过setHeaderIcon，setHeaderTitle，setHeaderView来设置头，否则就没有头。

4，弹出的方式不一样。

使用ContextMenu主要需要重载Activity的以下函数：

#### public void onCreateContextMenu ([ContextMenu][] menu, [View][] v, [ContextMenu.ContextMenuInfo][] menuInfo) ####

#### public void onContextMenuClosed ([Menu][] menu) ####

#### public boolean onContextItemSelected ([MenuItem][] item) ####

注意事项：ContextMenu的任何项在被选中后，整个ContextMenu会自动被系统关闭掉，即使多选项也是这样。这样的话，多选项的行为就有些怪异。查看Android的源码后，发现这是个Android的bug,应该是google没考虑多选项的情况。

实例1

文件ContextMenuActivity.java

package com.teleca;

import android.app.Activity;

import android.content.res.Resources;

import android.os.Bundle;

import android.util.Log;

import android.view.ContextMenu;

import android.view.Menu;

import android.view.MenuInflater;

import android.view.MenuItem;

import android.view.MotionEvent;

import android.view.SubMenu;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

public class  ContextMenuActivity  extends Activity \{

View myContextMenuView=null;

View myContextMenuView2=null;

View myContextMenuView3=null;

public void onCreate(Bundle savedInstanceState) \{

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

myContextMenuView=this.findViewById(R.id.TextView1);

myContextMenuView2=findViewById(R.id.TextView2);

myContextMenuView3=findViewById(R.id.view3);

public void   onResume()

super.onResume();

registerForContextMenu(myContextMenuView);

registerForContextMenu(myContextMenuView2);

registerForContextMenu(myContextMenuView3);

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

super.onCreateContextMenu(menu, v, menuInfo);

System.out.println("onCreateContextMenu");

int groupId=0;

int order=Menu.NONE;

int itemId=0;

Resources res=getResources();

String title=null;

if (v.getId()==R.id.TextView1)

menu.add(groupId, R.id.menuItem1, order,R.string.menuItem1);

MenuInflater inflater = getMenuInflater();

inflater.inflate(R.menu.contextmenu, menu);

else if (v.getId()==R.id.TextView2)

MenuInflater inflater = getMenuInflater();

inflater.inflate(R.menu.contextmenub, menu);

else if  (v.getId()==R.id.view3)

menu.add(groupId, R.id.menuItem1, order,R.string.menuItem1);

menu.add(groupId, R.id.menuItem2, order, R.string.menuItem2);

groupId++;

SubMenu subMenu=menu.addSubMenu(groupId, R.id.file, order, R.string.file);

subMenu.add(groupId, R.id.newFile, order, R.string.newFile);

subMenu.add(groupId, R.id.openFile, order, R.string.openFile);

groupId++;

menu.add(groupId, R.id.groupItem11, order, R.string.groupItem1);

menu.add(groupId, R.id.groupItem12, order, R.string.groupItem2);

menu.setGroupCheckable(groupId, false, false);

groupId++;

menu.add(groupId, R.id.groupItem21, order, R.string.groupItem1);

menu.add(groupId, R.id.groupItem22, order, R.string.groupItem2);

menu.setGroupCheckable(groupId, true, true);

groupId++;

menu.add(groupId, R.id.groupItem31, order, R.string.groupItem1);

menu.add(groupId, R.id.groupItem32, order, R.string.groupItem2);

menu.add(groupId, R.id.groupItem33, order, R.string.groupItem3);

menu.setGroupCheckable(groupId, true, false);

menu.setHeaderIcon(R.drawable.icon);

menu.setHeaderTitle("My Context Menu");

public boolean  onContextItemSelected (MenuItem item)

int id=item.getItemId();

if (id==R.id.menuItem1||id==R.id.menuItem2

||id==R.id.file||id==R.id.newFile||id==R.id.openFile

||id==R.id.group1)

System.out.println("menu:"+item.getTitle()+"is slected");

return true;

else if (item.isCheckable())

if (item.isChecked())

item.setChecked(false);

else

item.setChecked(true);

System.out.println("menu:"+item.getTitle()+"is cheked and slected");

return true;

else if (id==R.id.groupItem11||id==R.id.groupItem12)

System.out.println("menu Group:"+item.getTitle()+"is slected");

return true;

else

return super.onContextItemSelected(item);

final static  String tag="robin";

public void  onContextMenuClosed (Menu menu)

System.out.println("menu:is closed");

菜单文件1

menu\\contextmenu.xml

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

<item android:id="@+id/menuItem2"

android:title="@string/menuItem2" />

<item android:id="@+id/file"

android:title="@string/file" >

<menu>

<item android:id="@+id/newFile"

android:title="@string/newFile" />

<item android:id="@+id/openFile"

android:title="@string/openFile" />

</menu>

</item>

<group android:id="@+id/group1"

android:checkableBehavior="single">

<item android:id="@+id/groupItem11"

android:title="@string/groupItem1" />

<item android:id="@+id/groupItem12"

android:title="@string/groupItem2" />

</group>

</menu>

菜单文件2

menu\\contextmenub.xml

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

<item android:id="@+id/menuItem1"

android:title="@string/menuItem1" />

<item android:id="@+id/menuItem2"

android:title="@string/menuItem2" />

<item android:id="@+id/file"

android:title="@string/file" >

<menu>

<item android:id="@+id/newFile"

android:title="@string/newFile" />

<item android:id="@+id/openFile"

android:title="@string/openFile" />

</menu>

</item>

<group android:id="@+id/group1"

android:checkableBehavior="none">

<item android:id="@+id/groupItem11"

android:title="@string/groupItem1" />

<item android:id="@+id/groupItem12"

android:title="@string/groupItem2" />

</group>

<group android:id="@+id/group2"

android:checkableBehavior="single">

<item android:id="@+id/groupItem21"

android:title="@string/groupItem1" />

<item android:id="@+id/groupItem22"

android:title="@string/groupItem2" />

</group>

<group android:id="@+id/group3"

android:checkableBehavior="all">

<item android:id="@+id/groupItem31"

android:title="@string/groupItem1" />

<item android:id="@+id/groupItem32"

android:title="@string/groupItem2" />

<item android:id="@+id/groupItem33"

android:title="@string/groupItem3" />

</group>

</menu>

字符串文件strings.xml

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

<string name="hello">Hello World, MainActivity!</string>

<string name="app\_name">HelloWorld</string>

<string name="app\_name2">HelloWorld2</string>

<string name="pressme">please press me!</string>

<string name="clone">clone me!</string>

<string name="ActivityInfo">print ActivityInfo!</string>

<string name="ContextMenuSample">static and dynamic ContextMenuSample</string>

<string name="staticContextMenuSample">staticContextMenuSample</string>

<string name="menuItem1">menuItem1</string>

<string name="menuItem2">menuItem2</string>

<string name="menuItem3">menuItem3</string>

<string name="groupItem1">groupItem1</string>

<string name="groupItem2">groupItem2</string>

<string name="groupItem3">groupItem3</string>

</resources>

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[registerForContextMenu_View]: http://developer.android.com/reference/android/app/Activity.html#registerForContextMenu%28android.view.View%29
[ContextMenu]: http://developer.android.com/reference/android/view/ContextMenu.html
[View]: http://developer.android.com/reference/android/view/View.html
[ContextMenu.ContextMenuInfo]: http://developer.android.com/reference/android/view/ContextMenu.ContextMenuInfo.html
[Menu]: http://developer.android.com/reference/android/view/Menu.html
[MenuItem]: http://developer.android.com/reference/android/view/MenuItem.html
[https_blog.csdn.net_jiangjunshow]: https://blog.csdn.net/jiangjunshow/article/details/77338485