android WindowManager的简单使用

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"><uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" /><uses-permission android:name="android.permission.SYSTEM_OVERLAY_WINDOW" /><applicationandroid:allowBackup="true"android:dataExtractionRules="@xml/data_extraction_rules"android:fullBackupContent="@xml/backup_rules"android:icon="@mipmap/ic_launcher"android:label="@string/app_name"android:roundIcon="@mipmap/ic_launcher_round"android:supportsRtl="true"android:theme="@style/Theme.App0"tools:targetApi="31"><activityandroid:name=".MainActivity"android:exported="true"><intent-filter><action android:name="android.intent.action.MAIN" /><category android:name="android.intent.category.LAUNCHER" /></intent-filter></activity></application></manifest>

package com.koala.app0;import androidx.appcompat.app.AppCompatActivity;import android.content.Context;
import android.graphics.PixelFormat;
import android.os.Bundle;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.ImageView;public class MainActivity extends AppCompatActivity {private static Context context;private Button button;private View imageView;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);context = getApplication().getApplicationContext();button = findViewById(R.id.btn1);imageView = LayoutInflater.from(context).inflate(R.layout.png,null);button.setOnClickListener(listener);}private View.OnClickListener listener =  new View.OnClickListener(){@Overridepublic void onClick(View v) {WindowManager.LayoutParams layoutParams = new WindowManager.LayoutParams();
//            layoutParams.format = PixelFormat.RGBA_8888;layoutParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;
//            layoutParams.width = 200;
//            layoutParams.height = 200;//            layoutParams.type = WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY;//            layoutParams.gravity = Gravity.BOTTOM | Gravity.LEFT;layoutParams.x = 30;layoutParams.y = 40;WindowManager windowManager = getWindowManager();windowManager.addView(imageView,layoutParams);}};public static Context getContext(){return context;}
}