android 状态栏怎么显示音乐信息 安卓音乐通知栏进度条

项目中需要用到通知栏进度条，查找了好多资料、链接如下：

1. Android 为Notification加上一个进度条
2. Android实现Service后台下载Notification进度条
3. Notification使用详解之三：通过服务更新进度通知&在Activity中监听服务进度
4. android service startService bindService
5. Android中BindService方式使用的理解
6. [Android 机制] 大家帮忙看一下这个BUG.
7. Android 的service的定义可以 作为内部类使用吗？

我先简后难写了两种实现，第一个没有使用服务，activity转向后台进度条消失；另一个使用服务，activity转向后台进度条仍然继续。

以下是第一个实现：

主界面布局代码 notify.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="开始" />

</LinearLayout>

通知栏内容布局代码 notify_content.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >


    <ProgressBar
        android:id="@+id/progressBar1"
        style="?android:attr/progressBarStyleHorizontal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="14dp"
        android:layout_toRightOf="@+id/imageView1" />

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_below="@+id/progressBar1"
        android:layout_marginRight="26dp"/>

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/textView1"
        android:layout_alignParentLeft="true"
        android:src="@drawable/ic_launcher" />

</RelativeLayout>

AndroidManifest.xml 代码添加如下：

<activity
            android:label="@string/app_name"
            android:name=".notify.NotificationActivity1" >
            <intent-filter >
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

主程序NotificationActivity1.java代码如下：

package com.zhang.new_test.notify;

import android.app.Activity;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.RemoteViews;
import android.widget.Toast;

import com.zhang.new_test.R;

public class NotificationActivity1 extends Activity implements OnClickListener {

    private static final int NOTIFICATION_ID = 0x12;
    private Notification notification = null;
    private NotificationManager manager = null;
    private int _progress = 0;
    private boolean isStop = false;

    @Override
    protected void onPause() {
        isStop = false;
        manager.cancel(NOTIFICATION_ID);

        super.onPause();
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.notify);

        Button btn = (Button) findViewById(R.id.button1);
        btn.setOnClickListener(this);
        notification = new Notification(R.drawable.sg, "带进条的提醒", System.currentTimeMillis());

        notification.contentView = new RemoteViews(getApplication().getPackageName(), R.layout.notify_content);
        notification.contentView.setProgressBar(R.id.progressBar1, 100, 0, false);
        notification.contentView.setTextViewText(R.id.textView1, "进度" + _progress + "%");
        
        notification.contentIntent = PendingIntent.getActivity(this, 0,new Intent(this, NotificationActivity1.class), 0);
      
        manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);

    }
    
    @Override
    public void onClick(View v) {
        isStop = true;
        manager.notify(NOTIFICATION_ID, notification);
        new ProgressThread().start();
    }
    
    private class ProgressThread extends Thread {

        @Override
        public void run() {
            while (isStop) {
                _progress += 10;
                Message msg = handler.obtainMessage();
                msg.arg1 = _progress;
                msg.sendToTarget();

                try {
                    Thread.sleep(500);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }
    
    public Handler handler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            notification.contentView.setProgressBar(R.id.progressBar1, 100, msg.arg1, false);
            notification.contentView.setTextViewText(R.id.textView1, "进度" + msg.arg1 + "%");
            manager.notify(NOTIFICATION_ID, notification);

            if (msg.arg1 == 100) {
                _progress = 0;
                manager.cancel(NOTIFICATION_ID);
                isStop = false;
                Toast.makeText(NotificationActivity1.this, "下载完毕", 1000).show();
            }
        }
    };
}

以下是第二个实现：

主界面布局代码 notify.xml和通知栏内容布局代码 notify_content.xml同上一个实现

AndroidManifest.xml 代码添加如下：

<activity
            android:label="@string/app_name"
            android:name=".notify.NotificationActivity2" >
            <intent-filter >
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        
        <service android:name=".notify.NotificationActivity2$DownLoadService"/>

主程序NotificationActivity2.java代码如下：

package com.zhang.new_test.notify;

import android.app.Activity;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Binder;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.RemoteViews;
import android.widget.Toast;

import com.zhang.new_test.R;

public class NotificationActivity2 extends Activity implements OnClickListener {
	
    private DownLoadService downLoadService;
	
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.notify);
        
        Button btn = (Button) findViewById(R.id.button1);
        btn.setOnClickListener(this);
    }
    
    @Override
    protected void onResume() {
    	super.onResume();
    	
        Intent serviceIntent = new Intent(this,DownLoadService.class);
        startService(serviceIntent);//
        bindService(serviceIntent, serviceConnection, Context.BIND_AUTO_CREATE);
    }
    
    @Override
    protected void onPause() {
    	super.onPause();
    	
    	unbindService(serviceConnection);
    }
    
    @Override
    public void onClick(View v) {
    	downLoadService.startDownLoad();
    }
    
	private ServiceConnection serviceConnection = new ServiceConnection() {
		
		@Override
		public void onServiceConnected(ComponentName name, IBinder service){
			downLoadService = ((DownLoadService.DownLoadServiceBinder) service).getService();
			Toast.makeText(NotificationActivity2.this, "Service Connected.", Toast.LENGTH_LONG).show();
		}
		
		@Override
		public void onServiceDisconnected(ComponentName name) {
		}
	};
	
	public static class DownLoadService extends Service {

	    private static final int NOTIFICATION_ID = 0x12;
	    private Notification notification = null;
	    private NotificationManager manager = null;
	    private int _progress = 0;
	    private boolean isStop = false;
	    
		private Binder serviceBinder = new DownLoadServiceBinder();

		@Override
		public void onCreate() {
			super.onCreate();
			
	        notification = new Notification(R.drawable.sg, "带进条的提醒", System.currentTimeMillis());

	        notification.contentView = new RemoteViews(getApplication().getPackageName(), R.layout.notify_content);
	        notification.contentView.setProgressBar(R.id.progressBar1, 100, 0, false);
	        notification.contentView.setTextViewText(R.id.textView1, "进度" + _progress + "%");
	        
	        notification.contentIntent = PendingIntent.getActivity(this, 0,new Intent(this, NotificationActivity1.class), 0);
	      
	        manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
		}
		
		@Override
		public IBinder onBind(Intent intent) {
			return serviceBinder;
		}

		@Override
		public void onDestroy() {
	        isStop = false;
	        manager.cancel(NOTIFICATION_ID);
	        
			super.onDestroy();
		}
		
		public void startDownLoad() {
	        isStop = true;
	        manager.notify(NOTIFICATION_ID, notification);
			new ProgressThread().start();
		}

		public class DownLoadServiceBinder extends Binder {
			public DownLoadService getService() {
				return DownLoadService.this;
			}
		}
		
	    private class ProgressThread extends Thread {

	        @Override
	        public void run() {
	            while (isStop) {
	                _progress += 10;
	                Message msg = handler.obtainMessage();
	                msg.arg1 = _progress;
	                msg.sendToTarget();

	                try {
	                    Thread.sleep(1000);
	                } catch (InterruptedException e) {
	                    e.printStackTrace();
	                }
	            }
	        }
	    }
	    
	    public Handler handler = new Handler() {
	        @Override
	        public void handleMessage(Message msg) {
	            notification.contentView.setProgressBar(R.id.progressBar1, 100, msg.arg1, false);
	            notification.contentView.setTextViewText(R.id.textView1, "进度" + msg.arg1 + "%");
	            manager.notify(NOTIFICATION_ID, notification);

	            if (msg.arg1 == 100) {
	                _progress = 0;
	                manager.cancel(NOTIFICATION_ID);
	                isStop = false;
	                Toast.makeText(DownLoadService.this, "下载完毕", 1000).show();
	            }
	        }
	    };
	}
}

效果我就不贴图了，前面提到的链接中有，效果差不多。

接下来分析一下代码，第二个和第一个最大区别是引入了service，这样可以支持后台运行，所以第二个更有实用性。但是刚开始写代码，不应该引入服务，那样会带来过多的复杂度，出bug时很难调试，写完第一个在重构引入服务就没那么麻烦了，大部分代码可以复用的。

主要知识点就是Notification和bindService的使用，我主要遇到两个悲剧，和大家分享一下：

1. 忘了unbindService，抛了一个不知道的异常，链接6解决了
2. .notify.NotificationActivity2$DownLoadService 我写成了 .notify.NotificationActivity2.DownLoadService，链接7解决了，这个花了半天时间，我就不相信这个会错，主要是因为写代码时new 静态内部类时都是用 . 啊，忘了配置是用的反射，所以应该用 $ 啊，主要是以前没写过静态内部类的反射，记住教训了。