新手报错...
import java.util.ArrayList;
import android.os.Bundle;
import android.app.Activity;
import android.annotation.SuppressLint;
import android.app.PendingIntent;
import android.content.Intent;
import android.telephony.SmsManager;
import android.view.View;
import android.widget.*;

@SuppressLint("NewApi")
public class MainActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnSend = (Button) findViewById(R.id.btnSend);
edtPhoneNo = (EditText) findViewById(R.id.edtPhoneNo);
edtContent = (EditText) findViewById(R.id.edtContent);


当中的R就是报错额。。。
ID 和LAYOUT在R文件里都是有的
求解 在线等