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:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
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 }