Android悬浮框，在Service中打开悬浮窗；在Service中打开Dialog；

文章介绍了如何在Service中显示悬浮框，在Service中弹出Dialog，在Service中做耗时的轮询操作；

背景需求：

公司的项目现在的逻辑是这样的：发送一个指令，然后3秒一次轮询去查询这个指令是否成功，在这期间界面有遮盖不可操作；

然后需求改了，因为遮盖界面不让用户操作体验不好；现在的需求是：这个轮询查询指令是否成功的操作在后端进行，界面有一个悬浮框用来提示用户正在查询指令；

嗯，在后端查询指令让用户无感，可以用Service实现，然后悬浮框使用WindowMessage实现，轮询查询指令使用Handler或IntentService实现；大致就是这样，先来个Demo；

1、开启服务：需要的信息由Activity使用Intent传递给Service；

Intent intent = new Intent(this,MyService.class);
        intent.putExtra("args","晨");
        startService(intent);

public class MyService extends Service {

    public MyService() {
    }

    @Override
    public IBinder onBind(Intent intent) {
        throw new UnsupportedOperationException("Not yet implemented");
    }

    @Override
    public void onCreate() {
        super.onCreate();

    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
       args = intent.getStringExtra("args");
        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
    }
}

Service中的onCreate只在创建的时候执行一次，onStartCommand()每次开启这个Service都会执行；同时别忘记这个注册：

  <service
            android:name=".MyService"
            android:enabled="true"
            android:exported="true" />

2、在Service开启成功后创建悬浮框，

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
       args = intent.getStringExtra("args");
       initView();
        return super.onStartCommand(intent, flags, startId);
    }

 /**
     * 使用系统级别的WindowManager展示悬浮框，需要6.0以上的权限；
     */
    private void initView() {
        if (Build.VERSION.SDK_INT >= 23) {
            if (!Settings.canDrawOverlays(this)) {
                Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION);
                intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                intent.setData(Uri.parse( "package:"+"com.example.administrator.xuanfudemo"));  //应用的包名，可直接跳转到这个应用的悬浮窗设置；
                startActivity(intent);
            } else {
                openWindow();
            }
        }else {
            openWindow();
        }
    }

    private void openWindow(){
        windowManager = (WindowManager) this.getSystemService(WINDOW_SERVICE);
        WindowManager.LayoutParams layoutParams = new WindowManager.LayoutParams();
        layoutParams.height = ViewGroup.LayoutParams.WRAP_CONTENT;
        layoutParams.width = ViewGroup.LayoutParams.WRAP_CONTENT;
        layoutParams.type = WindowManager.LayoutParams.TYPE_SYSTEM_ALERT;
//        layoutParams.type = WindowManager.LayoutParams.TYPE_APPLICATION_ATTACHED_DIALOG;
//        layoutParams.token = this.getWindow().getDecorView().getWindowToken();  //这样设置，在activity中打开悬浮框可绕过权限；
        layoutParams.flags =  WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL;
        layoutParams.format = PixelFormat.TRANSLUCENT;  //透明
        layoutParams.gravity = Gravity.TOP | Gravity.RIGHT;  //右上角显示
        view = LayoutInflater.from(this).inflate(R.layout.view_win,null);
        windowManager.addView(view,layoutParams);
    }

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

悬浮框需要权限，而且这个权限属于危险级权限，API23以上需要用户手动开启；

3、使用Handler轮询查询指令；

查询到指令后弹框提示，弹出Dialog。在Service中弹出Dialog需要设置下方代码，同时还要有弹窗权限；

dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);

 private Handler mHandler = new Handler(){
        @Override
        public void dispatchMessage(Message msg) {
            super.dispatchMessage(msg);
            switch (msg.what){
                case HANDLERSIGN:
                    Log.i(TAG, "dispatchMessage: "+args+(++num));
                    mHandler.sendEmptyMessageDelayed(HANDLERSIGN,HANDLERTIME);
                    if (num == 5){
                        AlertDialog.Builder builder = new AlertDialog.Builder(MyService.this);
                        builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialogInterface, int i) {
                                MyService.this.stopSelf();
                            }
                        });
                        AlertDialog dialog = builder.create();
                        dialog.setMessage("我的计数"+num);
                        dialog.setTitle("提示");
                        dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
                        dialog.show();
                    }
                    break;
            }
        }
    };

    private final String TAG = "ccb";
    private String args;
    private int num;
    private final int HANDLERSIGN = 10;
    private final int HANDLERTIME = 2010;

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
       args = intent.getStringExtra("args");
       initView();
        initData();
        return super.onStartCommand(intent, flags, startId);
    }

  private void initData() {
        mHandler.sendEmptyMessageDelayed(HANDLERSIGN,HANDLERTIME);
    }

4、在服务销毁时，清空Handler信息关闭悬浮框；

    @Override
    public void onDestroy() {
        super.onDestroy();
        Log.i(TAG, "onDestroy: 啊，ByKill");
        mHandler.removeCallbacksAndMessages(null);
        if (windowManager != null) windowManager.removeView(view);
    }

全部的Service代码：

悬浮框我使用了两种，另外一种是FloatWindow，有兴趣的可以去GitHub查一下；

package com.example.administrator.xuanfudemo;

import android.Manifest;
import android.app.AlertDialog;
import android.app.Service;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.PixelFormat;
import android.net.Uri;
import android.os.Build;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.provider.Settings;
import android.support.v4.app.ActivityCompat;
import android.util.Log;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.WindowManager;

import com.yhao.floatwindow.FloatWindow;
import com.yhao.floatwindow.PermissionListener;
import com.yhao.floatwindow.Screen;
import com.yhao.floatwindow.ViewStateListener;

public class MyService extends Service {

    private WindowManager windowManager;
    private View view;

    public MyService() {
    }

    @Override
    public IBinder onBind(Intent intent) {
        throw new UnsupportedOperationException("Not yet implemented");
    }

    @Override
    public void onCreate() {
        super.onCreate();

    }

    private Handler mHandler = new Handler(){
        @Override
        public void dispatchMessage(Message msg) {
            super.dispatchMessage(msg);
            switch (msg.what){
                case HANDLERSIGN:
                    Log.i(TAG, "dispatchMessage: "+args+(++num));
                    mHandler.sendEmptyMessageDelayed(HANDLERSIGN,HANDLERTIME);
                    if (num == 5){
                        AlertDialog.Builder builder = new AlertDialog.Builder(MyService.this);
                        builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialogInterface, int i) {
                                MyService.this.stopSelf();
//                                if (windowManager != null) windowManager.removeView(view);
                            }
                        });
                        AlertDialog dialog = builder.create();
                        dialog.setMessage("我的计数"+num);
                        dialog.setTitle("提示");
                        dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
                        dialog.show();
                    }
                    break;
            }
        }
    };

    private final String TAG = "ccb";
    private String args;
    private int num;
    private final int HANDLERSIGN = 10;
    private final int HANDLERTIME = 2010;
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
       args = intent.getStringExtra("args");
//       initView();
       initView2();
        initData();
        return super.onStartCommand(intent, flags, startId);
    }

    /**
     * FloatWindow使用FloatWindow库展示悬浮框；可拖拽
     */
    private void initView2() {
        FloatWindow
                .with(getApplicationContext())
                .setView(LayoutInflater.from(this).inflate(R.layout.view_win,null))
                .setWidth(100)                               //设置控件宽高
                .setHeight(Screen.height,0.2f)
                .setX(100)                                   //设置控件初始位置
                .setY(Screen.height,0.3f)
                .setDesktopShow(true)                        //桌面显示
                .setViewStateListener(new ViewStateListener() {
                    @Override
                    public void onPositionUpdate(int i, int i1) {

                    }

                    @Override
                    public void onShow() {

                    }

                    @Override
                    public void onHide() {

                    }

                    @Override
                    public void onDismiss() {

                    }

                    @Override
                    public void onMoveAnimStart() {

                    }

                    @Override
                    public void onMoveAnimEnd() {

                    }

                    @Override
                    public void onBackToDesktop() {

                    }
                })
                .setPermissionListener(new PermissionListener() {
                    @Override
                    public void onSuccess() {

                    }

                    @Override
                    public void onFail() {

                    }
                })
                .build();
        FloatWindow.get().show();
    }

    /**
     * 使用系统级别的WindowManager展示悬浮框，需要6.0以上的权限；
     */
    private void initView() {
        if (Build.VERSION.SDK_INT >= 23) {
            if (!Settings.canDrawOverlays(this)) {
                Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION);
                intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                intent.setData(Uri.parse( "package:"+"com.example.administrator.xuanfudemo"));
                startActivity(intent);
            } else {
                openWindow();
            }
        }else {
            openWindow();
        }
    }

    private void openWindow(){
        windowManager = (WindowManager) this.getSystemService(WINDOW_SERVICE);
        WindowManager.LayoutParams layoutParams = new WindowManager.LayoutParams();
        layoutParams.height = ViewGroup.LayoutParams.WRAP_CONTENT;
        layoutParams.width = ViewGroup.LayoutParams.WRAP_CONTENT;
        layoutParams.type = WindowManager.LayoutParams.TYPE_SYSTEM_ALERT;
//        layoutParams.type = WindowManager.LayoutParams.TYPE_APPLICATION_ATTACHED_DIALOG;
//        layoutParams.token = this.getWindow().getDecorView().getWindowToken();
        layoutParams.flags =  WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL;
        layoutParams.format = PixelFormat.TRANSLUCENT;
        layoutParams.gravity = Gravity.TOP | Gravity.RIGHT;
        view = LayoutInflater.from(this).inflate(R.layout.view_win,null);
        windowManager.addView(view,layoutParams);
    }

    private void initData() {
        mHandler.sendEmptyMessageDelayed(HANDLERSIGN,HANDLERTIME);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        Log.i(TAG, "onDestroy: 啊，ByKill");
        mHandler.removeCallbacksAndMessages(null);
        if (windowManager != null) windowManager.removeView(view);
        FloatWindow.destroy();
    }
}