Android属性动画赏析

为什么有Animation了,还要有Animator呢?

Animation有局限性,看下面代码.

XML布局:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.zhong.tutu.MainActivity">

<android.support.v7.widget.AppCompatImageView
android:id="@+id/image_view"
android:onClick="click"
android:background="@mipmap/ic_launcher"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<Button
android:id="@+id/button"
android:text="点击"
android:onClick="move"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"/>

</RelativeLayout>

MainActicity文件

package com.zhong.tutu;

import android.animation.ObjectAnimator;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.ImageView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

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

}
public void click(View view){
Toast.makeText(this,"我的土司",Toast.LENGTH_SHORT).show();
}

public void move(View view){
//        TranslateAnimation trans = new TranslateAnimation(0,200,0,100);
//        trans.setDuration(3000);
//        trans.setFillAfter(true);
ImageView image_view =(ImageView) findViewById(R.id.image_view);
//        image_view.startAnimation(trans);
ObjectAnimator.ofFloat(image_view,"translationX",0f,200f).setDuration(1000).start();
}
}

可以发现Animation只是改变了位置,看似改变.实际上并没有改变,不适合交互;于是有了Animator;

package com.zhong.tutu;

import android.animation.Animator;
import android.animation.AnimatorSet;
import android.animation.ObjectAnimator;
import android.animation.PropertyValuesHolder;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.animation.AnimationSet;
import android.view.animation.TranslateAnimation;
import android.widget.ImageView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

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

}

public  void click(View view){
Toast.makeText(this,"我是imageview",Toast.LENGTH_SHORT).show();
}

public  void move(View view){
// TranslateAnimation transA = new TranslateAnimation(0,200,0,0);
//        transA.setDuration(1000);
//        transA.setFillAfter(true);

ImageView imageView = (ImageView) findViewById(R.id.image_view);
//        imageView.startAnimation(transA);

//属性动画
//        ObjectAnimator.ofFloat(imageView,"translationX",0f,200f).setDuration(1000).start();
//        ObjectAnimator.ofFloat(imageView,"translationY",0f,200f).setDuration(1000).start();
//        ObjectAnimator.ofFloat(imageView,"rotation",0f,200f).setDuration(400).start();

/*    //同时作用于3个动画  PropertyValuesHolder对动画进行优化
PropertyValuesHolder p1 = PropertyValuesHolder.ofFloat("rotation", 0f, 200f);
PropertyValuesHolder p2 = PropertyValuesHolder.ofFloat("translationX", 0f, 200f);
PropertyValuesHolder p3 = PropertyValuesHolder.ofFloat("translationY", 0f, 200f);
ObjectAnimator.ofPropertyValuesHolder(imageView,p1,p2,p3).setDuration(1000).start();*/

ObjectAnimator t1 = ObjectAnimator.ofFloat(imageView, "translationX", 0f, 200f);
ObjectAnimator t2 =ObjectAnimator.ofFloat(imageView,"translationY",0f,200f);
ObjectAnimator t3 = ObjectAnimator.ofFloat(imageView,"rotation",0f,200f);

AnimatorSet set = new AnimatorSet();
set.play(t1).with(t2);
set.play(t3).after(t2);
//  set.playSequentially(t1,t2,t3);
set.setDuration(1000);
set.start();

}
}

动画的监听事件

package com.zhong.animatordemo;

import android.animation.Animator;

import android.animation.AnimatorListenerAdapter;

import android.animation.ObjectAnimator;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.view.View;

import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

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

}
public void click(View view){
ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(view,"alpha",0f,1f);
objectAnimator.setDuration(1000);
objectAnimator.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
Toast.makeText(MainActivity.this," onAnimationEnd",Toast.LENGTH_SHORT).show();
}
});
/* objectAnimator.addListener(new Animator.AnimatorListener() {
@Override
public void onAnimationStart(Animator animation) {

}

@Override
public void onAnimationEnd(Animator animation) {
Toast.makeText(MainActivity.this," onAnimationEnd",Toast.LENGTH_SHORT).show();
}

@Override
public void onAnimationCancel(Animator animation) {

}

@Override
public void onAnimationRepeat(Animator animation) {

}
});*/
objectAnimator.start();

}

}

“`