从Java activity类调用自定义视图的Kotlin类中的动画

import android.content.Context
import android.util.AttributeSet
import android.view.View
import android.view.animation.Animation
import android.view.animation.AnimationUtils

class CustomView @JvmOverloads constructor(
    context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : View(context, attrs, defStyleAttr) {

    private var animation: Animation? = null

    init {
        // 初始化动画
        animation = AnimationUtils.loadAnimation(context, R.anim.custom_animation)
    }

    fun startAnimation() {
        // 启动动画
        startAnimation(animation)
    }

    fun stopAnimation() {
        // 停止动画
        clearAnimation()
    }
}

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

    private CustomView customView;

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

        // 获取自定义视图的引用
        customView = findViewById(R.id.custom_view);

        // 调用自定义视图的方法来启动动画
        customView.startAnimation();
    }
}