注意：要首先注册开启和关闭WiFi的权限，
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"package="com.wyl.wifi"android:versionCode="1"android:versionName="1.0" ><uses-sdkandroid:minSdkVersion="8"android:targetSdkVersion="19" /><applicationandroid:allowBackup="true"android:icon="@drawable/ic_launcher"android:label="@string/app_name"android:theme="@style/AppTheme" ><activityandroid:name="com.wyl.wifi.MainActivity"android:label="@string/app_name" ><intent-filter><action android:name="android.intent.action.MAIN" /><category android:name="android.intent.category.LAUNCHER" /></intent-filter></activity></application><!-- 注册WiFi的权限 --><uses-permission android:name="android.permission.ACCESS_WIFI_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.CHANGE_NETWORK_STATE"></uses-permission>
</manifest>
MainActivity.java
package com.wyl.wifi;import android.content.Context;
import android.database.sqlite.SQLiteOpenHelper;
import android.net.wifi.WifiManager;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;public class MainActivity extends ActionBarActivity {Button btn;Button btn2;Button btn3;TextView tv;EditText et;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);btn = (Button) findViewById(R.id.btn01);// 检查网卡btn2 = (Button) findViewById(R.id.btn02);// 开启网卡btn3 = (Button) findViewById(R.id.btn03);// 关闭网卡et = (EditText)findViewById(R.id.editText2);StartWifiListener start = new StartWifiListener();CloseWifiListener close = new CloseWifiListener();btn2.setOnClickListener(start);btn3.setOnClickListener(close);}class StartWifiListener implements OnClickListener{@Overridepublic void onClick(View v) {//最重要的就是先获取到WifiManagerWifiManager wifiman = (WifiManager)MainActivity.this.getSystemService(Context.WIFI_SERVICE);wifiman.setWifiEnabled(true);//开启WiFiSystem.out.println("wifi state --->"+wifiman.getWifiState());Toast.makeText(MainActivity.this, ""+wifiman.getWifiState(), Toast.LENGTH_LONG);}}class CloseWifiListener implements OnClickListener{@Overridepublic void onClick(View v) {WifiManager wifiman = (WifiManager)MainActivity.this.getSystemService(Context.WIFI_SERVICE);wifiman.setWifiEnabled(false);//关闭WiFiSystem.out.println("wifi state --->"+wifiman.getWifiState());Toast.makeText(MainActivity.this, ""+wifiman.getWifiState(), Toast.LENGTH_LONG);}}}
