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();
}
}