ContextMenu介绍：

假设一个View注冊了上下文菜单。那么当长按该View时便会弹出一个浮动菜单，来供选择下一步操作。

实现这个功能须要调用setOnCreateContextMenuListener来注冊一个监听器。那么它和注冊长按监听器setOnLongClickListener有什么差别呢？以下会在代码中加以測试，通过加入打印发现，用户对某个View长按之后。首先触发的是onLongClick函数，运行onLongClick操作，然后依据onLongClick的返回值推断是不是运行OnCreateContextMenuListener函数。假设onLongClick返回false。则会继续运行OnCreateContextMenuListener函数，假设返回true。忽略OnCreateContextMenuListener函数。

代码例如以下：

public class MainActivity extends ActionBarActivity {

ImageView mImageView ;

MyContextMenuClickListener mContextListener;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.fragment_main);

mImageView = (ImageView) findViewById(R.id.image);

mContextListener = new MyContextMenuClickListener();

mImageView.setOnCreateContextMenuListener(mContextListener);

//test

mImageView.setOnLongClickListener(new OnLongClickListener() {

@Override

public boolean onLongClick(View arg0) {

// TODO Auto-generated method stub

Log.d("Test", "onLongClick");

return false;

}

});

}

private class MyContextMenuClickListener implements OnCreateContextMenuListener , OnMenuItemClickListener{

@Override

public boolean onMenuItemClick(MenuItem item) {

// TODO Auto-generated method stub

switch(item.getItemId()){

case R.id.open:

Log.d("Test", "click open");

break;

case R.id.delete:

Log.d("Test", "click delete");

break;

case R.id.remove:

Log.d("Test", "click remove");

break;

default:

break;

}

return true;

}

@Override

public void onCreateContextMenu(ContextMenu menu, View v,

ContextMenuInfo menuInfo) {

// TODO Auto-generated method stub

Log.d("Test", "onCreateContextMenu");

MenuInflater inflater = getMenuInflater();

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

LayoutInflater layoutInflater = getLayoutInflater();

View view = (View) layoutInflater.inflate(

R.layout.menu_header, null);

menu.setHeaderView(view);

MenuItem open = menu.findItem(R.id.open);

open.setOnMenuItemClickListener(mContextListener);

MenuItem delete = menu.findItem(R.id.delete);

delete.setOnMenuItemClickListener(mContextListener);

MenuItem remove = menu.findItem(R.id.remove);

remove.setOnMenuItemClickListener(mContextListener);

}

}

}

context_menu.xml

>

android:title="delete"/>

android:title="open"/>

android:title="remove"/>

menu_header.xml

xml version="1.0" encoding="UTF-8"?

>

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

android:layout_height="wrap_content"

android:layout_width="wrap_content"

>

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="This is a Test"

/>

假设须要自己关闭ContextMenu弹框。能够调用：

getActivity().closeContextMenu();