Android Studio菜单

系统菜单
先在res文件项目创造mean 然后在 mean中创造.xml

//mean文件
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
 <item android:id="@+id/it1" android:title="第一个"></item>
    <item android:id="@+id/it2" android:title="第二个"></item>
    <item android:id="@+id/it3" android:title="第三个"></item>
</menu>

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

  <TextView
      android:id="@+id/tv"
      android:text="文字1"
      android:textSize="20sp"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"></TextView>
  <View
      android:layout_width="100dp"
      android:layout_height="match_parent"></View>
  <TextView

      android:id="@+id/tv1"
      android:text="文字2"
      android:textSize="20sp"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"></TextView>
</LinearLayout>

package com.example.day2;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.ContextMenu;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.PopupMenu;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    
    
private TextView tv,tv1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    
    
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //上下文菜单的控件。
        tv=findViewById(R.id.tv);
        registerForContextMenu(tv);//调用上下文菜单的方法。

        //弹出菜单
        tv1=findViewById(R.id.tv1);
       tv1.setOnClickListener(new View.OnClickListener() {
    
    
           @Override
           public void onClick(View view) {
    
    
               showtext();
           }
       });
    }
    private void showtext() {
    
    
        //构造者
        final PopupMenu popupMenu=new PopupMenu(this,tv1);
        popupMenu.inflate(R.menu.menu);

        popupMenu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() {
    
    
            @Override
            public boolean onMenuItemClick(MenuItem menuItem) {
    
    
                int itemId = menuItem.getItemId();
                switch (itemId){
    
    
                    case  R.id.it1:
                        Toast.makeText(MainActivity.this, "1", Toast.LENGTH_SHORT).show();
                        break;
                    case  R.id.it2:
                        Toast.makeText(MainActivity.this, "2", Toast.LENGTH_SHORT).show();
                        break;
                    case  R.id.it3:
                        Toast.makeText(MainActivity.this, "3", Toast.LENGTH_SHORT).show();
                        break;
                }

                return false;

            }

        });
        popupMenu.show();
    }
    //上下文菜单
    @Override
    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
    
    
        getMenuInflater().inflate(R.menu.menu,menu);
        super.onCreateContextMenu(menu, v, menuInfo);
    }

    @Override
    public boolean onContextItemSelected(@NonNull MenuItem item) {
    
    
        int itemId = item.getItemId();
        switch (itemId){
    
    
            case R.id.it1:
                Toast.makeText(this, "1", Toast.LENGTH_SHORT).show();
                break;
            case R.id.it2:
                Toast.makeText(this, "2", Toast.LENGTH_SHORT).show();
                break;
            case R.id.it3:
                Toast.makeText(this, "3", Toast.LENGTH_SHORT).show();
                break;
        }
        return super.onContextItemSelected(item);
    }


   //系统菜单
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
    
    
        getMenuInflater().inflate(R.menu.menu,menu);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
    
    
        int itemId = item.getItemId();
        switch (itemId){
    
    
            case R.id.it1:
                Toast.makeText(this, "1", Toast.LENGTH_SHORT).show();
                break;
            case R.id.it2:
                Toast.makeText(this, "2", Toast.LENGTH_SHORT).show();
                break;
            case R.id.it3:
                Toast.makeText(this, "3", Toast.LENGTH_SHORT).show();
                break;
        }
        return super.onOptionsItemSelected(item);
    }

    }

PopupWindow菜单

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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=".Main2Activity">
  <Button
      android:onClick="btt"
      android:text="开始"
      android:id="@+id/bt"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"></Button>

</LinearLayout>

package com.example.day2;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.PopupWindow;
import android.widget.TextView;
import android.widget.Toast;

public class Main2Activity extends AppCompatActivity {
    
    
private  Button bt;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    
    
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
         bt=findViewById(R.id.bt);


    }


    public void btt(View view) {
    
    
        final PopupWindow popupWindow = new PopupWindow(this);

        View view1=LayoutInflater.from(Main2Activity.this).inflate(R.layout.item,null);
        popupWindow.setContentView(view1);

        popupWindow.setHeight(ViewGroup.LayoutParams.WRAP_CONTENT);
        popupWindow.setWidth(600);

        TextView textView = view1.findViewById(R.id.tv1);
        TextView textView2 = view1.findViewById(R.id.tv2);
        TextView textView3 = view1.findViewById(R.id.tv3);

        textView.setOnClickListener(new View.OnClickListener() {
    
    
            @Override
            public void onClick(View v) {
    
    
                Toast.makeText(Main2Activity.this, "1", Toast.LENGTH_SHORT).show();
                popupWindow.dismiss();
            }
        });
        textView2.setOnClickListener(new View.OnClickListener() {
    
    
            @Override
            public void onClick(View v) {
    
    
                Toast.makeText(Main2Activity.this, "2", Toast.LENGTH_SHORT).show();
                popupWindow.dismiss();
            }
        });
        textView3.setOnClickListener(new View.OnClickListener() {
    
    
            @Override
            public void onClick(View v) {
    
    
                Toast.makeText(Main2Activity.this, "3", Toast.LENGTH_SHORT).show();
                popupWindow.dismiss();
            }
        });
        popupWindow.setOutsideTouchable(true);
        popupWindow.showAsDropDown(bt,0,0);

    }
}