java注册活动。类显示错误，无法解析符号：RegistrationActivity

Question

在最后一行注册活动。类显示错误无法解析符号：安卓 studio中的RegistrationActivity

包com。实例睿智的

import 安卓x.appcompat.app.AppCompatActivity;

import 安卓.content.Intent;
import 安卓.os.Bundle;
import 安卓.os.Handler;
import 安卓.view.animation.Animation;
import 安卓.view.animation.AnimationUtils;
import 安卓.widget.ImageView;
import 安卓.widget.TextView;

public class MainActivity extends AppCompatActivity {

    Animation topAnimation, bottomAnimation;
    ImageView sagacious_logos__1_;

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

        topAnimation = AnimationUtils.loadAnimation(this, R.anim.top_animation);
        bottomAnimation = AnimationUtils.loadAnimation(this, R.anim.bottom_animation);
        sagacious_logos__1_ = findViewById(R.id.logo);

        sagacious_logos__1_.setAnimation(topAnimation);

        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                Intent intent = new Intent(MainActivity.this, RegistrationActivity.class);
            }
        })

    }
}