懸浮窗是在系統上顯示的內容，好像微信視訊聊天時的小視窗一樣，在退出軟體後依然存在的一個視窗，本部落格以視窗中放一個button元件為例，簡單展示懸浮窗，其中包括了對Android 6.0以下、Android 6.0到Android 8.0、Android 8.0以上版本的處理，下面開始介紹實現方法：

1、MainActivity中的程式碼

public Button mFloatingButton;
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
 
  //初始化view
  initView();
 }
 //初始化view
 private void initView() {
  mFloatingButton=(Button) findViewById(R.id.floating_btn);
  mFloatingButton.setOnClickListener(this);
 }
 
 public void startFloatingButtonService(View view) {
  Log.e("測試流程","測試流程");
  if (FloatingService_Button.isStarted) {
   Log.e("測試流程2","測試流程2");
   return;
  }
  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {//判斷系統版本
   if (!Settings.canDrawOverlays(this)) {
    Toast.makeText(this,"當前無許可權，請授權",Toast.LENGTH_SHORT);
    Log.e("測試流程3","測試流程3");
    startActivityForResult(new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION,Uri.parse("package:" + getPackageName())),0);
   } else {
    Log.e("測試流程4","測試流程4");
    startService(new Intent(MainActivity.this,FloatingService_Button.class));
   }
  } else {
   startService(new Intent(MainActivity.this,FloatingService_Button.class));
  }
 
 }
 
 @Override
 protected void onActivityResult(int requestCode,int resultCode,Intent data) {
  if (requestCode == 0) {
   if (!Settings.canDrawOverlays(this)) {
    Log.e("測試流程5","測試流程5");
    Toast.makeText(this,"授權失敗",Toast.LENGTH_SHORT).show();
   } else {
    Log.e("測試流程6","測試流程6");
    Toast.makeText(this,"授權成功",Toast.LENGTH_SHORT).show();
    startService(new Intent(MainActivity.this,FloatingService_Button.class));
   }
  }
 }
 
 @Override
 public void onClick(View v) {
  switch (v.getId()){
   case R.id.floating_btn :
    startFloatingButtonService(v);
    break;
  }
 }

思路簡單解釋：點選彈出懸浮窗按鈕時，獲取版本並判斷“Build.VERSION.SDK_INT >= Build.VERSION_CODES.M”如果系統版本在6.0以下這不需要請求許可權，如果系統版本在6.0以上需要進行許可權檢測以及請求，獲取許可權後，彈出懸浮框

2、activity_main.xml程式碼

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:orientation="vertical"
 tools:context="com.example.jack_lin.suspendwindow.MainActivity">
 
 <Button
  android:id="@+id/floating_btn"
  style="@style/floatingBtn"
  android:text="@string/floating_btn" />
 
 
</LinearLayout>

簡單解釋：xml中沒什麼特別東西，線性佈局中放一個按鈕

3、FloatingService_Button的程式碼

public static boolean isStarted = false;
 
 private WindowManager windowManager;
 private WindowManager.LayoutParams layoutParams;
 
 private Button button;
 
 @Override
 public void onCreate() {
  super.onCreate();
  Log.e("進入服務1","進入服務1");
  isStarted = true;
  windowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
  layoutParams = new WindowManager.LayoutParams();
  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
   layoutParams.type = WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY;
  } else {
   layoutParams.type = WindowManager.LayoutParams.TYPE_PHONE;
  }
  layoutParams.format = PixelFormat.RGBA_8888;
  layoutParams.gravity = Gravity.LEFT | Gravity.TOP;
  layoutParams.flags = WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;
  layoutParams.width = 500;
  layoutParams.height = 100;
  layoutParams.x = 300;
  layoutParams.y = 300;
 }
 
 @Nullable
 @Override
 public IBinder onBind(Intent intent) {
  Log.e("進入服務2","進入服務2");
 
  return null;
 }
 
 @Override
 public int onStartCommand(Intent intent,int flags,int startId) {
  Log.e("進入服務3","進入服務3");
  showFloatingWindow();
  return super.onStartCommand(intent,flags,startId);
 }
 
 private void showFloatingWindow() {
  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {//判斷系統版本
   if (Settings.canDrawOverlays(this)) {
    button = new Button(getApplicationContext());
    button.setText("我是個button視窗");
    button.setBackgroundColor(Color.BLUE);
    windowManager.addView(button,layoutParams);
 
    button.setOnTouchListener(new FloatingOnTouchListener());
   }
  } else {
   button = new Button(getApplicationContext());
   button.setText("我是個button視窗");
   button.setBackgroundColor(Color.BLUE);
   windowManager.addView(button,layoutParams);
 
   button.setOnTouchListener(new FloatingOnTouchListener());
  }
 }
 
 private class FloatingOnTouchListener implements View.OnTouchListener {
  private int x;
  private int y;
 
  @Override
  public boolean onTouch(View view,MotionEvent event) {
   switch (event.getAction()) {
    case MotionEvent.ACTION_DOWN:
     x = (int) event.getRawX();
     y = (int) event.getRawY();
     break;
    case MotionEvent.ACTION_MOVE:
     int nowX = (int) event.getRawX();
     int nowY = (int) event.getRawY();
     int movedX = nowX - x;
     int movedY = nowY - y;
     x = nowX;
     y = nowY;
     layoutParams.x = layoutParams.x + movedX;
     layoutParams.y = layoutParams.y + movedY;
     windowManager.updateViewLayout(view,layoutParams);
     break;
    default:
     break;
   }
   return false;
  }
 }

思路簡單解釋：首先獲取WindowManager服務，然後定義並設定在window上顯示的layoutParams（此處需注意Android 8.0以上版本中LayoutParam裡的type變數變為TYPE_APPLICATION_OVERLAY與Android 8.0以下版本LayoutParam裡的type變數TYPE_PHONE不一樣，需要通過判斷系統版本進行區分），然後定義並設定在layoutParams上面顯示的Button按鈕以及監聽事件（此處的監聽事件主要是懸浮視窗拖動的監聽）最後將設定好的button與layoutParams新增入window中

4、AndroidManifest.xml中許可權新增

<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
<uses-permission android:name="android.permission.INTERNET" />

5、效果圖

原始碼下載地址：Android懸浮窗 原始碼下載

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支援我們。