Material Designer的低版本兼容实现（五）—— ActivityOptionsCompat

本文是对API中的方法做了介绍，如果想要看如何让这些方法兼容4.x或2.x可以看这篇文章：

 用开源项目ActivityOptionsICS让ActivityOptions的动画实现兼容

新版的V4包中有了这个类—— ActivityOptionsCompat，我们可以通过这个类来启动activity和添加动画。但不幸的是所有的动画都没有给2.x用的，大部分动画也对4.x不兼容。我们就来看看是否让低版本也兼容这些动画效果。

好消息是这个类是兼容2.x的，通过这个类编写的嗲吗，虽然不能给2.x带来动画，但也能确保全版本稳定运行，不会需要我们判断版本。也就是说如果你给5.x平台做了动画，其他平台虽然不会执行动画，但仍旧可以稳定打开activity。下面我们通过远吗进行分析下这个类。

1.文档解释

（1）ActivityOptionsCompat.makeCustomAnimation(context, enterResId, exitResId)

简单做一个定制的动画，这个参数很简单，传入一个进入的动画的id，和移除动画的id即可

        //让新的Activity从一个小的范围扩大到全屏
        ActivityOptionsCompat options = 
                ActivityOptionsCompat.makeCustomAnimation(this, 
                        R.anim.slide_bottom_in, R.anim.slide_bottom_out);
        startNewAcitivity(options);

    
    private void startNewAcitivity(ActivityOptionsCompat options) {
        Intent intent = new Intent(this,DetailActivity.class);  
        ActivityCompat.startActivity(this, intent, options.toBundle());  
    }

这个我感觉没什么用处，类似于

        Intent intent = new Intent(this,DetailActivity.class);  
        startActivity(intent);

        overridePendingTransition(R.anim.slide_bottom_in, android.R.anim.fade_out);

还不如直接用这个全版本的overridePendingTransition呢

（2）ActivityOptionsCompat.makeScaleUpAnimation(source, startX, startY, startWidth, startHeight)

这个在4.x上有用，可以实现新的Activity从某个固定的坐标以某个大小扩大至全屏，我觉得效果挺不错的。

这个新Activity就是从根据那个图片的坐标来拉伸展示的，对于相册是很好的展示效果。

private void scaleUpAnimation(View view) {
        //让新的Activity从一个小的范围扩大到全屏
        ActivityOptionsCompat options = 
                ActivityOptionsCompat.makeScaleUpAnimation(view, //The View that the new activity is animating from
                        (int)view.getWidth()/2, (int)view.getHeight()/2, //拉伸开始的坐标
                        0, 0);//拉伸开始的区域大小，这里用（0，0）表示从无到全屏
        startNewAcitivity(options);
    }

    private void startNewAcitivity(ActivityOptionsCompat options) {
        Intent intent = new Intent(this,DetailActivity.class);  
        ActivityCompat.startActivity(this, intent, options.toBundle());  
    }

（3）ActivityOptionsCompat.makeSceneTransitionAnimation(activity, sharedElement, sharedElementName)

当你需要当前界面中的某个元素和新界面中的元素有关时，你可以使用这个动画。效果很赞~！

这个图片就是通过动画和上一个界面的图片进行了联系。

要使用这个方法就必须给两个不同Activity的中的布局元素设定同样的一个android:transitionName，然后还需要一个标志来告诉Window执行动画，因为这个只是在5.x上有效，不是本文的讨论范围。详细看官方文档即可。

标志：etWindow().requestFeature(Window.FEATURE_CONTENT_TRANSITIONS);

也可以参考文章：

http://blog.csdn.net/a396901990/article/details/40187203

http://blog.jobbole.com/77015/

（4）ActivityOptionsCompat.makeSceneTransitionAnimation((Activity arg0, Pair<View, String>...  arg1)

这个方法用于多个元素和新的Activity相关的情况，注意下第二个参数Pair这个键值对后面有...，标明是可以传入多个Pair对象的。

（5）ActivityOptionsCompat.makeThumbnailScaleUpAnimation(source, thumbnail, startX, startY)

这个方法可以用于4.x上，是将一个小块的Bitmpat进行拉伸的动画。

详细使用方式，参考官方文档：https://developer.android.com/training/material/animations.html

2.源码

看完了文档，心里各种凄凉。很多优秀的动画都不向下兼容，那么我们去源码中看看我们的主流4.x版本能用上什么。

public class ActivityOptionsCompat {
    /**
     * Create an ActivityOptions specifying a custom animation to run when the
     * activity is displayed.
     *
     * @param context Who is defining this. This is the application that the
     * animation resources will be loaded from.
     * @param enterResId A resource ID of the animation resource to use for the
     * incoming activity. Use 0 for no animation.
     * @param exitResId A resource ID of the animation resource to use for the
     * outgoing activity. Use 0 for no animation.
     * @return Returns a new ActivityOptions object that you can use to supply
     * these options as the options Bundle when starting an activity.
     */
    public static ActivityOptionsCompat makeCustomAnimation(Context context,
            int enterResId, int exitResId) {
        if (Build.VERSION.SDK_INT >= 16) {
            return new ActivityOptionsImplJB(
                ActivityOptionsCompatJB.makeCustomAnimation(context, enterResId, exitResId));
        }
        return new ActivityOptionsCompat();
    }

    /**
     * Create an ActivityOptions specifying an animation where the new activity is
     * scaled from a small originating area of the screen to its final full
     * representation.
     * <p/>
     * If the Intent this is being used with has not set its
     * {@link android.content.Intent#setSourceBounds(android.graphics.Rect)},
     * those bounds will be filled in for you based on the initial bounds passed
     * in here.
     *
     * @param source The View that the new activity is animating from. This
     * defines the coordinate space for startX and startY.
     * @param startX The x starting location of the new activity, relative to
     * source.
     * @param startY The y starting location of the activity, relative to source.
     * @param startWidth The initial width of the new activity.
     * @param startHeight The initial height of the new activity.
     * @return Returns a new ActivityOptions object that you can use to supply
     * these options as the options Bundle when starting an activity.
     */
    public static ActivityOptionsCompat makeScaleUpAnimation(View source,
            int startX, int startY, int startWidth, int startHeight) {
        if (Build.VERSION.SDK_INT >= 16) {
            return new ActivityOptionsImplJB(
                ActivityOptionsCompatJB.makeScaleUpAnimation(source, startX, startY,
                        startWidth, startHeight));
        }
        return new ActivityOptionsCompat();
    }

    /**
     * Create an ActivityOptions specifying an animation where a thumbnail is
     * scaled from a given position to the new activity window that is being
     * started.
     * <p/>
     * If the Intent this is being used with has not set its
     * {@link android.content.Intent#setSourceBounds(android.graphics.Rect)},
     * those bounds will be filled in for you based on the initial thumbnail
     * location and size provided here.
     *
     * @param source The View that this thumbnail is animating from. This
     * defines the coordinate space for startX and startY.
     * @param thumbnail The bitmap that will be shown as the initial thumbnail
     * of the animation.
     * @param startX The x starting location of the bitmap, relative to source.
     * @param startY The y starting location of the bitmap, relative to source.
     * @return Returns a new ActivityOptions object that you can use to supply
     * these options as the options Bundle when starting an activity.
     */
    public static ActivityOptionsCompat makeThumbnailScaleUpAnimation(View source,
            Bitmap thumbnail, int startX, int startY) {
        if (Build.VERSION.SDK_INT >= 16) {
            return new ActivityOptionsImplJB(
                ActivityOptionsCompatJB.makeThumbnailScaleUpAnimation(source, thumbnail,
                        startX, startY));
        }
        return new ActivityOptionsCompat();
    }

/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.support.v4.app;

import android.app.ActivityOptions;
import android.content.Context;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.view.View;

class ActivityOptionsCompatJB {

    public static ActivityOptionsCompatJB makeCustomAnimation(Context context,
            int enterResId, int exitResId) {
        return new ActivityOptionsCompatJB(
            ActivityOptions.makeCustomAnimation(context, enterResId, exitResId));
    }

    public static ActivityOptionsCompatJB makeScaleUpAnimation(View source,
            int startX, int startY, int startWidth, int startHeight) {
        return new ActivityOptionsCompatJB(
            ActivityOptions.makeScaleUpAnimation(source, startX, startY, startWidth, startHeight));
    }

    public static ActivityOptionsCompatJB makeThumbnailScaleUpAnimation(View source,
            Bitmap thumbnail, int startX, int startY) {
        return new ActivityOptionsCompatJB(
            ActivityOptions.makeThumbnailScaleUpAnimation(source, thumbnail, startX, startY));
    }

    private final ActivityOptions mActivityOptions;

    private ActivityOptionsCompatJB(ActivityOptions activityOptions) {
        mActivityOptions = activityOptions;
    }

    public Bundle toBundle() {
        return mActivityOptions.toBundle();
    }

    public void update(ActivityOptionsCompatJB otherOptions) {
        mActivityOptions.update(otherOptions.mActivityOptions);
    }
}

我们可以完全了解到，4.x上能用的就这么三个动画效果，第一个第三我个人认为没啥用处，第二个效果好点，但仅仅适用于照片墙。于是就很悲剧了，这个新的类仅仅带来了低版本兼容不报错的效果，对于新的特性各种不支持。反过来想，反正动画这个东西对用户来说好看和不好看也没差，功能是最主要的。

这个是讲5.0动画效果的文章，如果做5.0开发的话可以看看。但我估计在4.x主流的今天，这些特效还只能自己写兼容包了。

http://blog.csdn.net/a396901990/article/details/40187203

动画

好了，虽然我们不能用这么酷炫的动画，但我们还可以用传统动画嘛。我研究了下图片放大的效果，写了一篇文章，其实还可以继续优化。贴上文章地址和效果图。

地址：http://www.cnblogs.com/tianzhijiexian/p/4095756.html

效果图：

下面分享下使用动画的方法，在启动activity的时候进行设置，然后在开启的activity中的onBackPressed()也进行相应的设置，就能出现流畅的效果啦。

举例：

MainActivity

    private void simpleStartActivity() {
        Intent intent = new Intent(this,DetailActivity.class);  
        startActivity(intent);
        //overridePendingTransition(R.anim.slide_left_in, R.anim.slide_right_out);
        overridePendingTransition(R.anim.slide_bottom_in, android.R.anim.fade_out);
    }

DetailActivity

package com.kale.activityoptionstest;

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;

public class DetailActivity extends ActionBarActivity{

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

    @Override
    public void onBackPressed() {
        super.onBackPressed();
        //overridePendingTransition(R.anim.slide_right_in, R.anim.slide_left_out);
        overridePendingTransition(0, R.anim.slide_bottom_out);
    }
    
}

这样就可以实现，第二个Activity从屏幕下方出现，按下返回键后会从屏幕下方离开了。

最后给出几个常用的动画效果

slide_bottom_in.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:interpolator="@android:anim/accelerate_decelerate_interpolator"
    android:shareInterpolator="true">

    <translate
        android:duration="300"
        android:fromYDelta="100%p"
        android:toYDelta="0.0" />

</set>

slide_bottom_out.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:interpolator="@android:anim/accelerate_decelerate_interpolator"
    android:shareInterpolator="true">

    <translate
        android:duration="300"
        android:fromYDelta="0.0"
        android:toYDelta="100%p" />

</set>

slide_left_in.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >

    <translate
        android:duration="300"
        android:fromXDelta="-100.0%p"
        android:toXDelta="0.0" />

</set>

slide_left_out.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >

    <translate
        android:duration="300"
        android:fromXDelta="0.0"
        android:toXDelta="-100.0%p" />

</set>

slide_right_in.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >

    <translate
        android:duration="300"
        android:fromXDelta="100.0%p"
        android:toXDelta="0.0" />

</set>

slide_right_out.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android" >

    <translate
        android:duration="300"
        android:fromXDelta="0.0"
        android:toXDelta="100.0%p" />

</set>

slide_top_in.xml

<?xml version="1.0" encoding="utf-8"?>  
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:startOffset="50">  

    <translate 
        android:fromYDelta="-100%p"
        android:toYDelta="0%p"
        android:duration="300"/>

    
</set> 

slide_top_out.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:startOffset="50" >

    <translate
        android:duration="300"
        android:fromYDelta="0%p"
        android:toYDelta="-100%p" />

</set>