Android ValueAnimator画动画

package com.example.myapp; import android.animation.ValueAnimator; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.util.AttributeSet; import android.view.View; public class CustomView extends View { private Paint paint; private float x; public CustomView(Context context) { super(context); init(); } public CustomView(Context context, AttributeSet attrs) { super(context, attrs); init(); } public CustomView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(); } private void init() { // 创建画笔对象 paint = new Paint(); paint.setColor(Color.BLUE); // 设置画笔颜色为蓝色 paint.setStyle(Paint.Style.FILL); // 设置画笔样式为填充 // 创建 ValueAnimator 对象 ValueAnimator animator = ValueAnimator.ofFloat(0f, 1f); animator.setDuration(1000); // 设置动画持续时间为 1 秒 animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { // 更新 x 坐标 x = (float)animation.getAnimatedValue() * getWidth(); // 重绘视图 invalidate(); } }); animator.start(); // 开始动画 } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); // 绘制圆形 canvas.drawCircle(x, getHeight() / 2f, 50f, paint); } }