android判断手机是否连网

import android.net.ConnectivityManager;

import android.net.NetworkInfo;

public static boolean isNetworkConnected(Context context)
{
if (context != null) 
{
 ConnectivityManager mConnectivityManager = (ConnectivityManager)context.getSystemService("connectivity");
 NetworkInfo mNetworkInfo = mConnectivityManager.getActiveNetworkInfo();
 if (mNetworkInfo != null) 
 {
return mNetworkInfo.isAvailable();
 }
}
return false;
}

权限：

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