Android基础-弹出式菜单

弹出式菜单主要是显示在按钮旁边的菜单主键 

主要分为四步:这里以添加了按钮控件为例

第一步:实例化对象

 //1.实例化PopupMenu对象(参数2：被锚定的view)
 PopupMenu menu = new PopupMenu(MainActivity.this, popupButton);

第二步：加载菜单的资源

         //2.加载菜单资源：利用MenuInflate将menu资源加载到PopupMenu.getMenu()所返回的对象中
                //将R.menu.xx对于的菜单资源加载到弹出式菜单中
 menu.getMenuInflater().inflate(R.menu.popup, menu.getMenu());

第三步:对于选项设置点击监听器

 //3.PopupMenu设置点击监听器
                menu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
                    @Override
                    public boolean onMenuItemClick(MenuItem item) {
                        switch (item.getItemId()) {
                            case R.id.copy:
                                Toast.makeText(MainActivity.this, "复制", Toast.LENGTH_LONG).show();
                                break;
                            case R.id.paste:
                                Toast.makeText(MainActivity.this, "粘贴", Toast.LENGTH_LONG).show();
                                break;

                        }
                        return false;
                    }
                });

第四步:进行menu的展示

  //4.千万不要忘记这一步,显示PopupMenu
                menu.show();

完整java代码

package com.example.imoocapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.util.Log;
import android.view.ActionMode;
import android.view.ContextMenu;
import android.view.Menu;
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 {

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

        Button popupButton = findViewById(R.id.popup_btn);
        findViewById(R.id.popup_btn).setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View view){
                //1.实例化PopupMenu对象(参数2：被锚定的view)
                PopupMenu menu = new PopupMenu(MainActivity.this, popupButton);
                //2.加载菜单资源：利用MenuInflate将menu资源加载到PopupMenu.getMenu()所返回的对象中
                //将R.menu.xx对于的菜单资源加载到弹出式菜单中
                menu.getMenuInflater().inflate(R.menu.popup, menu.getMenu());
                //3.PopupMenu设置点击监听器
                menu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
                    @Override
                    public boolean onMenuItemClick(MenuItem item) {
                        switch (item.getItemId()) {
                            case R.id.copy:
                                Toast.makeText(MainActivity.this, "复制", Toast.LENGTH_LONG).show();
                                break;
                            case R.id.paste:
                                Toast.makeText(MainActivity.this, "粘贴", Toast.LENGTH_LONG).show();
                                break;

                        }
                        return false;
                    }
                });
                //4.千万不要忘记这一步,显示PopupMenu
                menu.show();

            }
        });
    }




}

popup.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:title="复制"
        android:id="@+id/copy"/>
    <item android:title="粘贴"
        android:id="@+id/paste"/>
</menu>

activity.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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=".MainActivity">

    <Button
        android:id="@+id/ctx_btn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="上下文菜单"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/popup_btn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="弹出式菜单"
        app:layout_constraintTop_toBottomOf="@+id/ctx_btn"
        tools:layout_editor_absoluteX="16dp" />


</androidx.constraintlayout.widget.ConstraintLayout>