Java Android-使用AnimatorSet缩放动画

官方教程使用放大视图来放大

视图

。随着视图的扩展，它会产生向下移动的错觉。稍后，

AnimatorSet

将简单地向后播放，以创建缩小效果

我需要实现的恰恰相反。我需要从一个展开的视图开始，然后将其缩小为一个向上移动的较小视图：

在示例中，我似乎无法使用反转代码。该示例假定您首先放大视图并将其展开，然后将其收缩回原始缩略图图标

这是我到目前为止试过的。我的XML布局是

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent">

<LinearLayout android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="#1999da">             

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:orientation="horizontal"
        android:layout_gravity="center"
        android:gravity="center">

        <!-- The final shrunk image -->

        <ImageView
            android:id="@+id/thumb_button_1"
            android:layout_width="wrap_content"
            android:layout_height="50dp"
            android:layout_marginRight="1dp"
            android:visibility="invisible"/>

    </LinearLayout>

</LinearLayout>

<!-- The initial expanded image that needs to be shrunk -->

<ImageView
    android:id="@+id/expanded_image"
    android:layout_width="wrap_content"
    android:layout_height="125dp"
    android:layout_gravity="center"
    android:src="@drawable/title_logo_expanded"
    android:scaleType="centerCrop"/>

</FrameLayout>

我在

onCreate（）

中调用此方法，如下所示：

final View expandedImageView = findViewById(R.id.expanded_image);
new Handler().postDelayed(new Runnable(){
        public void run() {
            zoomImageFromThumbReverse(expandedImageView, R.drawable.title_logo_min, 1000);
        }}, 1000);

好了，就这样，伙计们。它不起作用了。我不知道为什么。演示示例工作得很好，那么为什么这个不工作呢？看一看，告诉我我是不是疯了

---

有人能识别错误吗？或者给我指出正确的方向？非常感谢您提供的所有帮助。

好的，我想您需要从图像和描述中向上缩小。我不能理解你的代码，它对我来说太复杂了（我是个傻瓜）。现在，我已经使用以下代码完成了您想要的操作。首先，我用一个图像视图声明一个相对布局，这个相对布局就是容器。我设置了初始宽度和高度，但稍后我们将从代码中更改它

<RelativeLayout
    android:id="@+id/container"
    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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity">


    <ImageView
        android:id="@+id/imageView"
        android:layout_width="400dp"
        android:layout_height="200dp"
        android:layout_centerHorizontal="true"
        android:scaleType="fitXY"
        android:src="@drawable/my_image"/>
</RelativeLayout>

我们必须在这里设置三个动画，宽度、高度和上边距（用于定位）。所以，我为animator的初始位置声明了三个变量，并在初始布局设置中计算它们。现在我们需要同时设置这三个变量的动画，这很容易

    private void startAnimation() {
        AnimatorSet animator = new AnimatorSet();

        Animator widthAnimator = ObjectAnimator.ofInt(this, "width", width, 200);
        widthAnimator.setInterpolator(new LinearInterpolator());

        Animator heightAnimator = ObjectAnimator.ofInt(this, "height", height, 100);
        heightAnimator.setInterpolator(new LinearInterpolator());

        Animator marginAnimator = ObjectAnimator.ofInt(this, "topMargin", topMargin, 0);
        marginAnimator.setInterpolator(new LinearInterpolator());

        animator.playTogether(widthAnimator, heightAnimator, marginAnimator);
        animator.setDuration(3000);
        animator.start();
    }

    public void setWidth(int w) {
        RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams) im.getLayoutParams();
        layoutParams.width = w;
        im.setLayoutParams(layoutParams);
    }

    public void setHeight(int h) {
        RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams) im.getLayoutParams();
        layoutParams.height = h;
        im.setLayoutParams(layoutParams);
    }

    public void setTopMargin(int m) {
        RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams) im.getLayoutParams();
        layoutParams.topMargin = m;
        im.setLayoutParams(layoutParams);
    }
}

---

这是我最终使用的解决方案：

private void applyAnimation(final View startView, final View finishView, long duration) {
    float scalingFactor = ((float)finishView.getHeight())/((float)startView.getHeight());

    ScaleAnimation scaleAnimation =  new ScaleAnimation(1f, scalingFactor,
                                                        1f, scalingFactor,
                                                        Animation.RELATIVE_TO_SELF, 0.5f,
                                                        Animation.RELATIVE_TO_SELF, 0.5f);

    scaleAnimation.setDuration(duration);
    scaleAnimation.setInterpolator(new AccelerateDecelerateInterpolator());

    Display display = getWindowManager().getDefaultDisplay();

    int H;

    if(Build.VERSION.SDK_INT >= 13){
        Point size = new Point();
        display.getSize(size);
        H = size.y;
    }
    else{
        H = display.getHeight();
    }

    float h = ((float)finishView.getHeight());

    float verticalDisplacement = (-(H/2)+(3*h/4));

    TranslateAnimation translateAnimation = new TranslateAnimation(Animation.ABSOLUTE, 0,
                                                                   Animation.ABSOLUTE, 0,
                                                                   Animation.ABSOLUTE, 0,
                                                                   Animation.ABSOLUTE, verticalDisplacement);

    translateAnimation.setDuration(duration);
    translateAnimation.setInterpolator(new AccelerateDecelerateInterpolator());

    AnimationSet animationSet = new AnimationSet(false);
    animationSet.addAnimation(scaleAnimation);
    animationSet.addAnimation(translateAnimation);
    animationSet.setFillAfter(false);

    startView.startAnimation(animationSet);
}

这里的关键因素是

TranslateAnimation

参数中

toYDelta

的值：

toYDelta = (-(H/2)+(3*h/4));

最主要的是要理解为什么这样做有效。剩下的大部分都很简单

private void applyAnimation(final View startView, final View finishView, long duration) {
    float scalingFactor = ((float)finishView.getHeight())/((float)startView.getHeight());

    ScaleAnimation scaleAnimation =  new ScaleAnimation(1f, scalingFactor,
                                                        1f, scalingFactor,
                                                        Animation.RELATIVE_TO_SELF, 0.5f,
                                                        Animation.RELATIVE_TO_SELF, 0.5f);

    scaleAnimation.setDuration(duration);
    scaleAnimation.setInterpolator(new AccelerateDecelerateInterpolator());

    Display display = getWindowManager().getDefaultDisplay();

    int H;

    if(Build.VERSION.SDK_INT >= 13){
        Point size = new Point();
        display.getSize(size);
        H = size.y;
    }
    else{
        H = display.getHeight();
    }

    float h = ((float)finishView.getHeight());

    float verticalDisplacement = (-(H/2)+(3*h/4));

    TranslateAnimation translateAnimation = new TranslateAnimation(Animation.ABSOLUTE, 0,
                                                                   Animation.ABSOLUTE, 0,
                                                                   Animation.ABSOLUTE, 0,
                                                                   Animation.ABSOLUTE, verticalDisplacement);

    translateAnimation.setDuration(duration);
    translateAnimation.setInterpolator(new AccelerateDecelerateInterpolator());

    AnimationSet animationSet = new AnimationSet(false);
    animationSet.addAnimation(scaleAnimation);
    animationSet.addAnimation(translateAnimation);
    animationSet.setFillAfter(false);

    startView.startAnimation(animationSet);
}

toYDelta = (-(H/2)+(3*h/4));