弹跳加载中自定义简单控件实现

package com.loaderman.customviewdemo;

import android.animation.Animator;
import android.animation.ValueAnimator;
import android.content.Context;
import android.util.AttributeSet;
import android.view.animation.AccelerateDecelerateInterpolator;


public class LoadingImageView extends android.support.v7.widget.AppCompatImageView {
    private int mTop;
    //当前动画图片索引
    private int mCurImgIndex = 0;
    //动画图片总张数
    private static int mImgCount = 3;

    public LoadingImageView(Context context) {
        super(context);
        init();
    }

    public LoadingImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public LoadingImageView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);

        mTop = top;
    }

    private void init() {
        ValueAnimator valueAnimator = ValueAnimator.ofInt(0, 100, 0);
        valueAnimator.setRepeatMode(ValueAnimator.RESTART);
        valueAnimator.setRepeatCount(ValueAnimator.INFINITE);
        valueAnimator.setDuration(2000);//动画时长
        valueAnimator.setInterpolator(new AccelerateDecelerateInterpolator());

        valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {//监听动画值得实时变化
            public void onAnimationUpdate(ValueAnimator animation) {
                Integer dx = (Integer) animation.getAnimatedValue();
                setTop(mTop - dx);//将控件移动到当前位置,注意都是相对父控件坐标位置
            }
        });

        valueAnimator.addListener(new Animator.AnimatorListener() {
            public void onAnimationStart(Animator animation) {
                setImageDrawable(getResources().getDrawable(R.drawable.pic_1));
            }

            public void onAnimationRepeat(Animator animation) {
                mCurImgIndex++;
                switch (mCurImgIndex % mImgCount) {
                    case 0:
                        setImageDrawable(getResources().getDrawable(R.drawable.pic_1));
                        break;
                    case 1:
                        setImageDrawable(getResources().getDrawable(R.drawable.pic_2));
                        break;
                    case 2:
                        setImageDrawable(getResources().getDrawable(R.drawable.pic_3));
                        break;
                }
            }

            public void onAnimationEnd(Animator animation) {

            }

            public void onAnimationCancel(Animator animation) {

            }
        });


        valueAnimator.start();
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:layout_gravity="center"
    tools:context="com.loaderman.customviewdemo.MainActivity">

    <com.loaderman.customviewdemo.LoadingImageView
        android:layout_width="50dp"
        android:layout_height="wrap_content"
        android:src="@drawable/pic_1"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="加载中……"/>


</LinearLayout>

效果: