安卓开发-动画java对象

package com.example.learn;

import androidx.appcompat.app.alertDialog;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.ObjectAnimator;
import android.animation.ValueAnimator;
import android.content.DialogInterface;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewAnimationUtils;
import android.view.ViewGroup;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.PopupWindow;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "leo";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ValueAnimator valueAnimator=ValueAnimator.ofFloat(0f,1f);
        valueAnimator.setDuration(2000);
        valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                float value=(float) animation.getAnimatedValue();
                Log.e(TAG, "onAnimationUpdate: "+value);
            }
        });
        valueAnimator.start();

        View textview=findViewById(R.id.iv);

        ObjectAnimator objectAnimator=ObjectAnimator.ofFloat(textview,"alpha",0f,1f);
        objectAnimator.setDuration(3000);
        objectAnimator.start();
        objectAnimator.addListener(new Animator.AnimatorListener() {
            @Override
            public void onAnimationStart(Animator animation) {

            }

            @Override
            public void onAnimationEnd(Animator animation) {

            }

            @Override
            public void onAnimationCancel(Animator animation) {

            }

            @Override
            public void onAnimationRepeat(Animator animation) {

            }
        });

        动画适配器
        objectAnimator.addListener(new AnimatorListenerAdapter() {
            @Override
            public void onAnimationStart(Animator animation) {
                super.onAnimationStart(animation);
            }
        });
    }

}