获取android 手机的mac

import android.net.wifi.WifiInfo;import android.net.wifi.WifiManager;import android.os.Bundle;import android.app.Activity;import android.content.Context;import android.widget.TextView;public class MainActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);TextView tv=(TextView)super.findViewById(R.id.text);WifiManager wifi = (WifiManager)getSystemService(Context.WIFI_SERVICE);WifiInfo info = wifi.getConnectionInfo();String    mac=  info.getMacAddress();tv.setText(mac);}}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"android:layout_width="match_parent"android:layout_height="match_parent"android:paddingBottom="@dimen/activity_vertical_margin"android:paddingLeft="@dimen/activity_horizontal_margin"android:paddingRight="@dimen/activity_horizontal_margin"android:paddingTop="@dimen/activity_vertical_margin"tools:context=".MainActivity" ><TextViewandroid:id="@+id/text"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="" /></RelativeLayout>

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