android—wifi

1.       什么是wifi？

     Wifi是一种无线联网的技术，以前通过网线连接电脑，现在通过无线电波来连网，常见的就是一个无限路由器，那么这个无限路由器的电波覆盖的有效范围都可以采用wifi连接方式进行连网，如果无线路由器连接了一条ADSL线路或者别的上网线路，则又被称为热点。

 

 

2.       获取wifi网卡的状态

 

是由一系列的整形常量来表示的，

WIFI_STATE_DISABLED: 网卡不可用             constant value        1

WIFI_STATE_DISABLING：WIFI正在关闭         constant value        0

WIFI_STATE_ENABLED:   WIFI网卡可用         constant value        3       

WIFI_STATE_ENABLING : WIFI网卡正在打开      constant value        2

WIFI_STATE_UNKNOWN:未知网卡状态

       

 

3.       操作wifi所需要的权限

 

<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"></uses-permission>

    <uses-permission android:name="android.permission.CHANGE_WIFI_STATE"></uses-permission>

    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>

    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"></uses-permission>

 

4.       改变wifi网卡的状态

 

改变wifi网卡的状态，

对wifi网卡进行操作，需要通过WifiManager对象来进行，获取该对象的方法如下:

WifiManger

WifiManger =( WifiManger)Context.getSystemService(Service.WIFI_SERVICE);

 

   打开wifi网卡

WifiManger.setWifiEnabled(ture);

  关闭wifi网卡

WifiManger.setEnable(false);

获取网卡当前的状态：

WifiManger.getWifiState();

代码如下：

View Code

 1 package com.wbk.wifi.activity;
 2 
 3 import android.app.Activity;
 4 import android.content.Context;
 5 import android.net.wifi.WifiManager;
 6 import android.os.Bundle;
 7 import android.view.View;
 8 import android.view.View.OnClickListener;
 9 import android.widget.Button;
10 import android.widget.Toast;
11 
12 public class Wifi_wbkActivity extends Activity
13 {
14     private Button startButton = null;
15     private Button stopButton = null;
16     private Button checkButton = null;
17 
18     private WifiManager wifiManager = null;
19 
20     @Override
21     public void onCreate(Bundle savedInstanceState)
22     {
23         super.onCreate(savedInstanceState);
24         setContentView(R.layout.main);
25         startButton = (Button) findViewById(R.id.startButton);
26         stopButton = (Button) findViewById(R.id.stopButton);
27         checkButton = (Button) findViewById(R.id.checkButton);
28         startButton.setOnClickListener(new startWifiListener());
29         stopButton.setOnClickListener(new stopWifiListener());
30         checkButton.setOnClickListener(new checkWifiListener());
31     }
32 
33     // 内部类，需要的是Wifi_wbkActivity的对象，所以Wifi_wbkActivity.this
34     class startWifiListener implements OnClickListener
35     {
36 
37         @Override
38         public void onClick(View v)
39         {
40             wifiManager = (WifiManager) Wifi_wbkActivity.this.getSystemService(Context.WIFI_SERVICE);
41             wifiManager.setWifiEnabled(true);
42             System.out.println("wifi start ----->" + wifiManager.getWifiState());
43             Toast.makeText(Wifi_wbkActivity.this, "当前wifi网卡状态为", wifiManager.getWifiState());
44         }
45     }
46 
47     class stopWifiListener implements OnClickListener
48     {
49 
50         @Override
51         public void onClick(View v)
52         {
53             wifiManager=(WifiManager)Wifi_wbkActivity.this.getSystemService(Context.WIFI_SERVICE);
54             wifiManager.setWifiEnabled(false);
55             System.out.println("wifi stop --->"+wifiManager.getWifiState());
56             Toast.makeText(Wifi_wbkActivity.this, "当前的wifi状态为", wifiManager.getWifiState());
57             
58         }
59 
60     }
61     class checkWifiListener implements OnClickListener{
62 
63         @Override
64         public void onClick(View v)
65         {
66             wifiManager=(WifiManager)Wifi_wbkActivity.this.getSystemService(Context.WIFI_SERVICE);
67             System.out.println("wifi state ----->"+wifiManager.getWifiState());
68             Toast.makeText(Wifi_wbkActivity.this, "当前的wifi状态为",  wifiManager.getWifiState());
69         }
70         
71     }
72 
73 }