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

 /**
  * 判断是否有网络连接
  * @param context
  * @return
  */
 public static boolean isConnect(Context context) {
  boolean _isConnect = false;
  ConnectivityManager conManager = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
  NetworkInfo network = conManager.getActiveNetworkInfo();
  if (network != null) {
   _isConnect = conManager.getActiveNetworkInfo().isAvailable();
  }
  return _isConnect;
 }

/**
  * 打开系统网络设置界面
  * @param context
  */
 public void setNetworkMethod(final Context context) {

  AlertDialog.Builder builder = new AlertDialog.Builder(context);
  builder.setTitle("提示信息").setMessage("未发现网络连接,是否进行设置?").setPositiveButton("设置", new DialogInterface.OnClickListener() {
   @Override
   public void onClick(DialogInterface dialog, int which) {
    // TODO Auto-generated method stub
    Intent intent = null;
    //3.0之前和之后API不同，需要判断
    if (android.os.Build.VERSION.SDK_INT > 10) {
     intent = new Intent(android.provider.Settings.ACTION_WIRELESS_SETTINGS);
    } else {
     intent = new Intent();
     ComponentName component = new ComponentName("com.android.settings", "com.android.settings.WirelessSettings");
     intent.setComponent(component);
     intent.setAction("android.intent.action.VIEW");
    }
    context.startActivity(intent);
   }
  }).setNegativeButton("取消", new DialogInterface.OnClickListener() {

   @Override
   public void onClick(DialogInterface dialog, int which) {
    // TODO Auto-generated method stub
    dialog.dismiss();
   }
  }).show();
 }

button.setOnClickListener(new View.OnClickListener() {
   @Override
   public void onClick(View view) {
    if (!isConnect(TwoActivity.this)){
     setNetworkMethod(TwoActivity.this);
    }
   }
  });