利用动画实现控件背景色渐变

1.动画文件：

<?xml version="1.0" encoding="utf-8"?>
<objectAnimator xmlns:android="http://schemas.android.com/apk/res/android"
    android:propertyName="backgroundColor"
    android:duration="5000"
    android:valueFrom="#ff0033"
    android:valueTo="#000099"
    android:repeatCount="infinite"
    android:repeatMode="reverse"
    android:valueType="intType">
</objectAnimator>

2.类文件：

package com.soft.colorchangingdemo;

import android.animation.AnimatorInflater;
import android.animation.ArgbEvaluator;
import android.animation.ObjectAnimator;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.widget.RelativeLayout;

public class MainActivity extends Activity {

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

    private void init() {
        RelativeLayout relativeLayout = (RelativeLayout) findViewById(R.id.relativeLayout);
        AnimationView animationView = new AnimationView(this);
        relativeLayout.addView(animationView);
    }

    public class AnimationView extends View {
        public AnimationView(Context context) {
            super(context);
            ObjectAnimator objectAnimator = (ObjectAnimator) AnimatorInflater
                    .loadAnimator(MainActivity.this, R.anim.coloranimation);
            objectAnimator.setEvaluator(new ArgbEvaluator());
            objectAnimator.setTarget(this);
            objectAnimator.start();
        }

    }

}