学步园

一、前方

在研究《Android类似360,QQ管家那样的悬浮窗》突发奇想，想把应用的图标也显示到状态栏上，类似手机QQ，而有消息来时改变状态栏上的图标显示。

二、原理

其实很研究完后，才发现，很简单：

2.1 显示图标在状态栏上

		NotificationManager nm = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
		Notification n = new Notification(
				resId, "Floats Start!", System.currentTimeMillis());
		
		// 将此通知放到通知栏的"Ongoing"即"正在运行"组中
		n.flags |= Notification.FLAG_ONGOING_EVENT;
		// 表明在点击了通知栏中的"清除通知"后，此通知不清除，
		// 经常与FLAG_ONGOING_EVENT一起使用
		n.flags |= Notification.FLAG_NO_CLEAR;
		
		PendingIntent pi = PendingIntent.getActivity(this, 0, getIntent(), 0);
		n.contentIntent = pi;
		n.setLatestEventInfo(this, "FloatsWindow", "start!", pi);
		nm.notify(NOTIFICATION_ID_ICON, n);

2.2 修改图标的显示

不用cancel这个通知，只需传入不同的resId，再通知即可。

package com.chris.floats.window;

import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.Gravity;
import android.view.WindowManager;
import android.app.Activity;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;

public class MainActivity extends Activity {

	private static WindowManager mWindowMgr = null;
	private WindowManager.LayoutParams mWindowMgrParams = null;
	private static FloatsWindowView mFloatsWindowView = null;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
	}
	
	@Override
	protected void onStop() {
		super.onStop();
		deleteIconToStatusbar();
	}

	/*
	 * 显示应用主界面时，去除悬浮层
	 * 修改状态栏上的图标
	 */
	@Override
	public void onWindowFocusChanged(boolean hasFocus) {
		if(hasFocus){
			if(mFloatsWindowView != null){
				mWindowMgr.removeView(mFloatsWindowView);
				mFloatsWindowView = null;
			}
			addIconToStatusbar(R.drawable.a0);
		}else{
			getWindowLayout();
			addIconToStatusbar(R.drawable.ic_launcher);
		}
	}

	private void initParams(){
		DisplayMetrics dm = getResources().getDisplayMetrics();
		mWindowMgrParams.x = dm.widthPixels - 136;
		mWindowMgrParams.y = 300;
		mWindowMgrParams.width = 136;
		mWindowMgrParams.height = 136;
	}

	private void getWindowLayout(){
		if(mFloatsWindowView == null){
			mWindowMgr = (WindowManager)getBaseContext().getSystemService(Context.WINDOW_SERVICE);
			mWindowMgrParams = new WindowManager.LayoutParams();
			
			/*
			 *  2003 在指悬浮在所有界面之上
			 *  (4.0+系统中，在下拉菜单下面，而在2.3中，在上拉菜单之上)
			 */
			mWindowMgrParams.type = 2003;
			mWindowMgrParams.format = 1;
			
			/*
	         * 代码实际是wmParams.flags |= FLAG_NOT_FOCUSABLE;
	         * 40的由来是wmParams的默认属性（32）+ FLAG_NOT_FOCUSABLE（8）
	         */
			mWindowMgrParams.flags = 40;
			mWindowMgrParams.gravity = Gravity.LEFT | Gravity.TOP;
			initParams();
			
			mFloatsWindowView = new FloatsWindowView(this);
			mWindowMgr.addView(mFloatsWindowView, mWindowMgrParams);
		}
	}
	
	private final static int NOTIFICATION_ID_ICON = 0x10000;
	/*
	 * 如果没有从状态栏中删除ICON，且继续调用addIconToStatusbar,
	 * 则不会有任何变化。除了：
	 * 如果，将notification中的resId设置不同的图标，则会显示不同
	 * 的图标
	 */
	private void addIconToStatusbar(int resId){
		NotificationManager nm = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
		Notification n = new Notification(
				resId, "Floats Start!", System.currentTimeMillis());
		
		// 将此通知放到通知栏的"Ongoing"即"正在运行"组中
		n.flags |= Notification.FLAG_ONGOING_EVENT;
		// 表明在点击了通知栏中的"清除通知"后，此通知不清除，
		// 经常与FLAG_ONGOING_EVENT一起使用
		n.flags |= Notification.FLAG_NO_CLEAR;
		
		PendingIntent pi = PendingIntent.getActivity(this, 0, getIntent(), 0);
		n.contentIntent = pi;
		n.setLatestEventInfo(this, "FloatsWindow", "start!", pi);
		nm.notify(NOTIFICATION_ID_ICON, n);
	}
	
	private void deleteIconToStatusbar(){
		NotificationManager nm = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
		nm.cancel(NOTIFICATION_ID_ICON);
	}
}

以上就是源码，当应用的焦点变化时，状态栏上的图片也会跟着变化。

源码下载地址：http://download.csdn.net/detail/qingye_love/5506825