寫在前面的話

1、內容參考自網路，
2、內容如果有不對的，希望可以指出或補充，
3、任務練習，

一、步驟展示

（一）準備

① 總體要求：

1、設計啟動服務界面，點擊按鈕啟動服務，服務執行耗時操作10秒，發送廣播給前端，

2、當下載完成時，發送廣播到主界面，彈出彈窗，提示：下載完成，

② 檔案準備：
在這里插入圖片描述
③ 清單檔案：

（二）代碼

1、布局

activity_main.xml

<?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"
    tools:context=".MainActivity"
    android:orientation="vertical"
    android:background="@mipmap/bg">

    <Button
        android:id="@+id/start_service_btn"

        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:backgroundTint="#50ffffff"
        android:text="開啟服務"
        android:textSize="20sp"/>
    <Button
        android:id="@+id/stop_service_btn"

        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:backgroundTint="#50ffffff"
        android:text="關閉服務"
        android:textSize="20sp"/>
    <Button
        android:id="@+id/service_state_btn"

        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:backgroundTint="#50ffffff"
        android:text="SERVICE狀態"
        android:textSize="20sp"/>

</LinearLayout>

dialog_download.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="300dp"
    android:layout_height="200dp"
    android:orientation="vertical">
    <!--頭部部分-->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:gravity="center"
        android:background="#145897">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="提示"
            android:textSize="20sp"
            android:textColor="@color/white"/>
    </LinearLayout>
    <!--內容提示部分-->
    <TextView
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:text="資源下載完成"
        android:textSize="20sp"
        android:textColor="@color/black"
        android:gravity="center"
        android:background="@color/white"/>
    <!--按鈕部分-->
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#e8e8e8"
        android:gravity="center">
        <Button
            android:id="@+id/dialog_btn"

            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="確定"
            android:textSize="15sp"
            android:backgroundTint="#fd8638"/>
    </LinearLayout>

</LinearLayout>

2、廣播

MyReceiver.java

package com.example.lian;

import android.app.AlertDialog;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.Toast;

public class MyReceiver extends BroadcastReceiver {
    private Button btn;

    @Override
    public void onReceive(Context context, Intent intent) {
        // 獲得廣播發送的資料
        AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(context);
        View view = LayoutInflater.from(context).inflate(R.layout.dialog_download,null,false);
        dialogBuilder.setView(view);//設定好了的對話框
        AlertDialog alertDialog = dialogBuilder.create();
        //按鈕的實作
        btn = view.findViewById(R.id.dialog_btn);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(context,"確認成功！",Toast.LENGTH_SHORT).show();
                alertDialog.dismiss();//關閉對話框
            }
        });
        alertDialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
        alertDialog.show();
    }
}

3、服務

MyService.java

package com.example.lian;

import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.app.Service;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.IBinder;
import android.view.WindowManager;
import android.widget.Toast;

public class MyService extends Service {

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

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

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        //下載對話框
        AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(getApplicationContext());
        dialogBuilder.setMessage("是否要下載資源");
        dialogBuilder.setNegativeButton("否", null);
        dialogBuilder.setPositiveButton("是", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                //進度對話框
                ProgressDialog progressDialog = new ProgressDialog(getApplicationContext());
                progressDialog.setMessage("請耐心等待10秒...");
                //在show()之前，要先設定Dialog的型別為TYPE_SYSTEM_ALERT才能正常彈出對話框
                progressDialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);//必有
                progressDialog.show();
                //關閉操作
                Thread thread = new Thread(new Runnable() {
                    @Override
                    public void run() {
                        try {
                            Thread.sleep(10000);//顯示10秒
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                        progressDialog.dismiss();//關閉ProgressDialog
                    }
                });
                thread.start();
                //監聽對話框是否已經關閉，關閉后彈出↓
                progressDialog.setOnDismissListener(new DialogInterface.OnDismissListener() {
                    @Override
                    public void onDismiss(DialogInterface dialog) {
                        //發送廣播
                        Intent intent = new Intent(MyService.this,MyReceiver.class);
                        sendBroadcast(intent);
                    }
                });
            }
        });
        AlertDialog dialog = dialogBuilder.create();
        dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
        dialog.show();

        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        Toast.makeText(this,"關閉服務成功",Toast.LENGTH_SHORT).show();
    }

}

4、活動視窗

MainActivity.java

package com.example.lian;

import androidx.appcompat.app.AppCompatActivity;

import android.app.ActivityManager;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import java.util.List;

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

    private Button mStartBtn, mStopBtn, mStateBtn;
    private Intent intent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //獲取控制元件
        mStartBtn = findViewById(R.id.start_service_btn);
        mStopBtn = findViewById(R.id.stop_service_btn);
        mStateBtn = findViewById(R.id.service_state_btn);
        //添加監聽器
        mStartBtn.setOnClickListener(this);
        mStopBtn.setOnClickListener(this);
        mStateBtn.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.start_service_btn:
                intent = new Intent(this, MyService.class);
                startService(intent);
                break;
            case R.id.stop_service_btn:
                intent = new Intent(this, MyService.class);
                stopService(intent);
                break;
            case R.id.service_state_btn:
                boolean serviceRun = isServiceRun(this,"com.example.lian.MyService");
                if(serviceRun == true){
                    Toast.makeText(this,"服務正在運行",Toast.LENGTH_SHORT).show();
                }else{
                    Toast.makeText(this,"服務已關閉",Toast.LENGTH_SHORT).show();
                }
                break;
        }
    }

    //判斷服務(com.example.lian.MyService)是否正在運行
    public boolean isServiceRun(Context context, String servicename) {
        
        ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
        //獲取正在運行的服務,引數：表示最多回傳的數量
        List<ActivityManager.RunningServiceInfo>  lists = activityManager.getRunningServices(40);
        //
        for(ActivityManager.RunningServiceInfo list: lists){
            //獲取正在運行的服務名稱并判斷
            if(servicename.equals(list.service.getClassName())){
                return true;
            }
        }
        return false;
    }
}

二、結果展示

運行效果如下，
在這里插入圖片描述

三、補充

Android如何在Service中執行耗時操作

轉載請註明出處，本文鏈接：https://www.uj5u.com/yidong/252703.html

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