android弹出菜单的例子

如果有空格，则Android弹出菜单在锚文本下方显示菜单，否则在锚文本上方显示菜单。如果你在弹出菜单之外单击，它将消失。

android.widget.PopupMenu是java.lang.Object类的直接子类。

Android弹出菜单示例

让我们看看如何在android中创建弹出菜单。

activity_main.xml

它仅包含一个按钮。

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="example.srcmini02.com.popupmenu.MainActivity">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/button"
        android:text="Click"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

popup_menu.xml

它包含三个项目，如下所示。它是在res / menu目录中创建的。

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:id="@+id/one"
        android:title="One" />
    <item
        android:id="@+id/two"
        android:title="Two"/>
    <item
        android:id="@+id/three"
        android:title="Three"/>
</menu>

活动类

单击按钮时将显示弹出菜单。

package example.srcmini02.com.popupmenu;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.PopupMenu;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
Button button;

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

        button = (Button) findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                //Creating the instance of PopupMenu
                PopupMenu popup = new PopupMenu(MainActivity.this, button);
                //Inflating the Popup using xml file
                popup.getMenuInflater().inflate(R.menu.popup_menu, popup.getMenu());

                //registering popup with OnMenuItemClickListener
                popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
                    public boolean onMenuItemClick(MenuItem item) {
                        Toast.makeText(MainActivity.this, "You Clicked : " + item.getTitle(), Toast.LENGTH_SHORT).show();
                        return true;
                    }
                });

                popup.show();//showing popup menu
            }
        });//closing the setOnClickListener method
    }
}

输出：