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