package com.example.myevent0;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import java.util.Date;

public class MyEvent0 extends AppCompatActivity
        implements View.OnClickListener {
    EditText txtbirthdate;
    Button showbio;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        showComponet();
    }
    public void showComponet(){
        txtbirthdate=(EditText)findViewById(R.id.txtbirthdate);
        showbio=(Button)findViewById(R.id.showbio);
        showbio.setOnClickListener(this);
    }
    @Override
    public void onClick(View v){
        if(v==showbio){
            String st = String.format("오늘은 %s다.",new Date());
            txtbirthdate.setText(st);
            Toast.makeText(getBaseContext(),st,Toast.LENGTH_LONG).show();
        }
    }
}

여기서 findviewbyid(R.id.변수)에서 변수부분에서 변수를 찾을수없다고뜨네요

txtbirthdate=(EditText)findViewById(R.id.txtbirthdate);// (error: cannot find symbol variable txtbirthdate) 
showbio=(Button)findViewById(R.id.showbio);//    (error: cannot find symbol variable showbio) 

혹시 아시는분 계실까요