原文:
Android自动连接指定的wifi，免密码或指定密码
一、运行时的状态
遇到一个这样的要求：“不进行扫描操作，怎么对指定的免密码WIFI进行连接（之前没有连接过）”，于是动手写了一个Demo，如图所示未连接成功时的状态，第一个编辑框让用户输入SSID，第二个编辑框输入密码，密码可以根据实例情况输入，也可以不输入密码，因为有些Wifi免密码。这里的免密码不是指可以破解wifi密码。注意图片中手机顶部的wifi图标，是没有的，说明此时并没有打开手机的wifi。在手机上运行状态如下所示：
输入SSID，点击连接后的状态，当手机的wifi没有打开时，程序将自动打开wifi，打开后再连接指定的wifi。
测试的手机信息如下：
二、功能实现
2.1、项目结构如下所示：
2.2、页面布局activity_main.xml文件如下所示：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" > <TextView android:id="@+id/txtSSID" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="SSID：" android:textSize="@dimen/activity_horizontal_margin" /> <EditText android:id="@+id/editSSID" android:layout_width="match_parent" android:layout_height="wrap_content" android:ems="10" android:text="FBI" > <requestFocus /> </EditText> <TextView android:id="@+id/TextView01" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Password：" android:textSize="@dimen/activity_horizontal_margin" /> <EditText android:id="@+id/editPwd" android:layout_width="match_parent" android:layout_height="wrap_content" android:ems="10" android:text="" /> <Button android:id="@+id/btnConnect" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Connect" /> <TextView android:id="@+id/txtMessage" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="" /> </LinearLayout>
2.3、清单文件AndroidManifest.xml内容如下，中间添加了对wifi访问的用户权限部分非常重要
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.wifigo" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="14" android:targetSdkVersion="19" /> <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> <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name=".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> </manifest>
2.4、Wifi连接管理类WifiConnector.java，有不少是参考热心网友的博客，谢谢了！
package com.example.wifigo; import java.util.List; import android.net.wifi.*; import android.net.wifi.WifiConfiguration.AuthAlgorithm; import android.net.wifi.WifiConfiguration.KeyMgmt; import android.os.Handler; import android.os.Message; import android.text.TextUtils; import android.util.Log; public class WifiConnector { Handler mHandler; WifiManager wifiManager; /** * 向UI发送消息 * @param info 消息 */ public void sendMsg(String info) { if (mHandler != null) { Message msg = new Message(); msg.obj = info; mHandler.sendMessage(msg);// 向Handler发送消息 } else { Log.e("wifi", info); } } //WIFICIPHER_WEP是WEP ，WIFICIPHER_WPA是WPA，WIFICIPHER_NOPASS没有密码 public enum WifiCipherType { WIFICIPHER_WEP, WIFICIPHER_WPA, WIFICIPHER_NOPASS, WIFICIPHER_INVALID } // 构造函数 public WifiConnector(WifiManager wifiManager) { this.wifiManager = wifiManager; } // 提供一个外部接口，传入要连接的无线网 public void connect(String ssid, String password, WifiCipherType type) { Thread thread = new Thread(new ConnectRunnable(ssid, password, type)); thread.start(); } // 查看以前是否也配置过这个网络 private WifiConfiguration isExsits(String SSID) { List<WifiConfiguration> existingConfigs = wifiManager .getConfiguredNetworks(); for (WifiConfiguration existingConfig : existingConfigs) { if (existingConfig.SSID.equals("\"" + SSID + "\"")) { return existingConfig; } } return null; } private WifiConfiguration createWifiInfo(String SSID, String Password, WifiCipherType Type) { WifiConfiguration config = new WifiConfiguration(); config.allowedAuthAlgorithms.clear(); config.allowedGroupCiphers.clear(); config.allowedKeyManagement.clear(); config.allowedPairwiseCiphers.clear(); config.allowedProtocols.clear(); config.SSID = "\"" + SSID + "\""; // nopass if (Type == WifiCipherType.WIFICIPHER_NOPASS) { config.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE); } // wep if (Type == WifiCipherType.WIFICIPHER_WEP) { if (!TextUtils.isEmpty(Password)) { if (isHexWepKey(Password)) { config.wepKeys[0] = Password; } else { config.wepKeys[0] = "\"" + Password + "\""; } } config.allowedAuthAlgorithms.set(AuthAlgorithm.OPEN); config.allowedAuthAlgorithms.set(AuthAlgorithm.SHARED); config.allowedKeyManagement.set(KeyMgmt.NONE); config.wepTxKeyIndex = 0; } // wpa if (Type == WifiCipherType.WIFICIPHER_WPA) { config.preSharedKey = "\"" + Password + "\""; config.hiddenSSID = true; config.allowedAuthAlgorithms .set(WifiConfiguration.AuthAlgorithm.OPEN); config.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.TKIP); config.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.WPA_PSK); config.allowedPairwiseCiphers .set(WifiConfiguration.PairwiseCipher.TKIP); // 此处需要修改否则不能自动重联 // config.allowedProtocols.set(WifiConfiguration.Protocol.WPA); config.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.CCMP); config.allowedPairwiseCiphers .set(WifiConfiguration.PairwiseCipher.CCMP); config.status = WifiConfiguration.Status.ENABLED; } return config; } // 打开wifi功能 private boolean openWifi() { boolean bRet = true; if (!wifiManager.isWifiEnabled()) { bRet = wifiManager.setWifiEnabled(true); } return bRet; } class ConnectRunnable implements Runnable { private String ssid; private String password; private WifiCipherType type; public ConnectRunnable(String ssid, String password, WifiCipherType type) { this.ssid = ssid; this.password = password; this.type = type; } @Override public void run() { try { // 打开wifi openWifi(); sendMsg("opened"); Thread.sleep(200); // 开启wifi功能需要一段时间(我在手机上测试一般需要1-3秒左右)，所以要等到wifi // 状态变成WIFI_STATE_ENABLED的时候才能执行下面的语句 while (wifiManager.getWifiState() == WifiManager.WIFI_STATE_ENABLING) { try { // 为了避免程序一直while循环，让它睡个100毫秒检测…… Thread.sleep(100); } catch (InterruptedException ie) { } } WifiConfiguration wifiConfig = createWifiInfo(ssid, password, type); // if (wifiConfig == null) { sendMsg("wifiConfig is null!"); return; } WifiConfiguration tempConfig = isExsits(ssid); if (tempConfig != null) { wifiManager.removeNetwork(tempConfig.networkId); } int netID = wifiManager.addNetwork(wifiConfig); boolean enabled = wifiManager.enableNetwork(netID, true); sendMsg("enableNetwork status enable=" + enabled); boolean connected = wifiManager.reconnect(); sendMsg("enableNetwork connected=" + connected); sendMsg("连接成功!"); } catch (Exception e) { // TODO: handle exception sendMsg(e.getMessage()); e.printStackTrace(); } } } private static boolean isHexWepKey(String wepKey) { final int len = wepKey.length(); // WEP-40, WEP-104, and some vendors using 256-bit WEP (WEP-232?) if (len != 10 && len != 26 && len != 58) { return false; } return isHex(wepKey); } private static boolean isHex(String key) { for (int i = key.length() - 1; i >= 0; i--) { final char c = key.charAt(i); if (!(c >= '0' && c <= '9' || c >= 'A' && c <= 'F' || c >= 'a' && c <= 'f')) { return false; } } return true; } }
2.5、MainActivity.java代码，完成接收用户的输入与调用wifi连接功能，如下所示：
package com.example.wifigo; import com.example.wifigo.WifiConnector.WifiCipherType; import android.app.Activity; import android.content.Context; import android.net.wifi.WifiManager; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; import android.widget.Toast; public class MainActivity extends Activity { Button btnConnect; WifiManager wifiManager; WifiConnector wac; TextView textView1; EditText editPwd; EditText editSSID; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); btnConnect = (Button) findViewById(R.id.btnConnect); textView1 = (TextView) findViewById(R.id.txtMessage); wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE); wac = new WifiConnector(wifiManager); editPwd=(EditText) findViewById(R.id.editPwd); editSSID=(EditText) findViewById(R.id.editSSID); wac.mHandler = new Handler() { @Override public void handleMessage(Message msg) { // 操作界面 textView1.setText(textView1.getText()+"\n"+msg.obj+""); super.handleMessage(msg); } }; btnConnect.setOnClickListener(new Button.OnClickListener() { @Override public void onClick(View v) { try { wac.connect(editSSID.getText().toString(), editPwd.getText().toString(), editPwd.getText().toString().equals("")?WifiCipherType.WIFICIPHER_NOPASS:WifiCipherType.WIFICIPHER_WPA); } catch (Exception e) { textView1.setText(e.getMessage()); } } }); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } }
2.6、小结
时间比较紧，代码比较粗糙，这毕竟只是一个demo，如果您需要使用在商业项目中这可能只具有抛砖引玉的作用了；另外测试时发现如果手机的wifi没有打开，依靠程序打开时程序会崩溃，后面发现有可能是打开wifi时需要一段时间，所以代码中增加了一些人为的延时操作，尽量用更加优雅的办法替代；我使用一台Android 4.x.x的meizu note 1手机和一个DLink DIR-600N的老路由器测试没有问题，使用自己的笔记本电脑作热点，带密码连接没有问题，这不代表在其它环境下就正常了。
2.7、参考示例：
