Android 判断SIM卡属于哪个移动运营商

package com.example.checksimoperator;

import com.unity3d.player.UnityPlayer;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.telephony.TelephonyManager;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

Button close = (Button)this.findViewById(R.id.button0);
close.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {

checkSIM();
}

});
}

public void checkSIM(){
TelephonyManager telManager = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
String operator = telManager.getSimOperator();
if (operator != null){
if (operator.equals("46000") || operator.equals("46002")){
Toast.makeText(this, "此卡属于(中国移动)", Toast.LENGTH_SHORT).show();
System.out.print("此卡属于(中国移动)");
UnityPlayer.UnitySendMessage("Main Camera","Messgae","YD");

} else if (operator.equals("46001")){
Toast.makeText(this, "此卡属于(中国联通)", Toast.LENGTH_SHORT).show();
System.out.print("此卡属于(中国联通)");
UnityPlayer.UnitySendMessage("Main Camera","Messgae","LT");
} else if (operator.equals("46003")){
Toast.makeText(this, "此卡属于(中国电信)", Toast.LENGTH_SHORT).show();
System.out.print("此卡属于(中国电信)");
UnityPlayer.UnitySendMessage("Main Camera","Messgae","DX");
}
}
}
}