假设我有一个垂直线性布局:

[v1]
[v2]

默认情况下,v1已经可见= GONE。我想用一个展开动画显示v1,同时下推v2。

我是这样做的:

Animation a = new Animation()
{
    int initialHeight;

    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t) {
        final int newHeight = (int)(initialHeight * interpolatedTime);
        v.getLayoutParams().height = newHeight;
        v.requestLayout();
    }

    @Override
    public void initialize(int width, int height, int parentWidth, int parentHeight) {
        super.initialize(width, height, parentWidth, parentHeight);
        initialHeight = height;
    }

    @Override
    public boolean willChangeBounds() {
        return true;
    }
};

但是用这个解决方案,当动画开始时我有一个眨眼。我认为这是由于v1在应用动画之前显示全尺寸。

用javascript,这是一行jQuery!android有什么简单的方法吗?


当前回答

我认为最简单的解决方案是设置android:animateLayoutChanges="true"到你的LinearLayout,然后通过设置其可见性来显示/隐藏视图。工作就像一个魅力,但你无法控制动画持续时间

其他回答

这是一个片段,我用来调整一个视图(线性布局)的宽度与动画。

代码应该根据目标大小进行扩展或收缩。如果你想要一个fill_parent宽度,你必须在将标志设置为true时将父类. getmeasuredwidth作为目标宽度。

希望它能帮助到你们中的一些人。

public class WidthResizeAnimation extends Animation {
int targetWidth;
int originaltWidth;
View view;
boolean expand;
int newWidth = 0;
boolean fillParent;

public WidthResizeAnimation(View view, int targetWidth, boolean fillParent) {
    this.view = view;
    this.originaltWidth = this.view.getMeasuredWidth();
    this.targetWidth = targetWidth;
    newWidth = originaltWidth;
    if (originaltWidth > targetWidth) {
        expand = false;
    } else {
        expand = true;
    }
    this.fillParent = fillParent;
}

@Override
protected void applyTransformation(float interpolatedTime, Transformation t) {
    if (expand && newWidth < targetWidth) {
        newWidth = (int) (newWidth + (targetWidth - newWidth) * interpolatedTime);
    }

    if (!expand && newWidth > targetWidth) {
        newWidth = (int) (newWidth - (newWidth - targetWidth) * interpolatedTime);
    }
    if (fillParent && interpolatedTime == 1.0) {
        view.getLayoutParams().width = -1;

    } else {
        view.getLayoutParams().width = newWidth;
    }
    view.requestLayout();
}

@Override
public void initialize(int width, int height, int parentWidth, int parentHeight) {
    super.initialize(width, height, parentWidth, parentHeight);
}

@Override
public boolean willChangeBounds() {
    return true;
}

}

public static void expand(final View v, int duration, int targetHeight) {
        v.measure(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        v.getLayoutParams().height = 0;
        v.setVisibility(View.VISIBLE);
        ValueAnimator valueAnimator = ValueAnimator.ofInt(0, targetHeight);
        valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            @Override
            public void onAnimationUpdate(ValueAnimator animation) {
                v.getLayoutParams().height = (int) animation.getAnimatedValue();
                v.requestLayout();
            }
        });
        valueAnimator.setInterpolator(new DecelerateInterpolator());
        valueAnimator.setDuration(duration);
        valueAnimator.start();
    }
public static void collapse(final View v, int duration, int targetHeight) {
    ValueAnimator valueAnimator = ValueAnimator.ofInt(0, targetHeight);
    valueAnimator.setInterpolator(new DecelerateInterpolator());
    valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
        @Override
        public void onAnimationUpdate(ValueAnimator animation) {
            v.getLayoutParams().height = (int) animation.getAnimatedValue();
            v.requestLayout();
        }
    });
    valueAnimator.setInterpolator(new DecelerateInterpolator());
    valueAnimator.setDuration(duration);
    valueAnimator.start();
}

这是一个合适的工作解决方案,我已经测试过了:

例如:

private void expand(View v) {
    v.setVisibility(View.VISIBLE);

    v.measure(View.MeasureSpec.makeMeasureSpec(PARENT_VIEW.getWidth(), View.MeasureSpec.EXACTLY),
            View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));

    final int targetHeight = v.getMeasuredHeight();

    mAnimator = slideAnimator(0, targetHeight);
    mAnimator.setDuration(800);
    mAnimator.start();
}

崩溃:

private void collapse(View v) {
    int finalHeight = v.getHeight();

    mAnimator = slideAnimator(finalHeight, 0);

    mAnimator.addListener(new Animator.AnimatorListener() {
        @Override
        public void onAnimationStart(Animator animator) {

        }

        @Override
        public void onAnimationEnd(Animator animator) {
            //Height=0, but it set visibility to GONE
            llDescp.setVisibility(View.GONE);
        }

        @Override
        public void onAnimationCancel(Animator animator) {

        }

        @Override
        public void onAnimationRepeat(Animator animator) {

        }
    });
    mAnimator.start();
}

动画师的值:

private ValueAnimator slideAnimator(int start, int end) {
    ValueAnimator mAnimator = ValueAnimator.ofInt(start, end);

    mAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
        @Override
        public void onAnimationUpdate(ValueAnimator valueAnimator) {
            //Update Height
            int value = (Integer) valueAnimator.getAnimatedValue();
            ViewGroup.LayoutParams layoutParams = llDescp.getLayoutParams();
            layoutParams.height = value;
            v.setLayoutParams(layoutParams);
        }
    });
    return mAnimator;
}

视图v是要被动画的视图,PARENT_VIEW是包含该视图的容器视图。

如果你不想扩展或折叠所有的方式-这里是一个简单的HeightAnimation -

import android.view.View;
import android.view.animation.Animation;
import android.view.animation.Transformation;

public class HeightAnimation extends Animation {
    protected final int originalHeight;
    protected final View view;
    protected float perValue;

    public HeightAnimation(View view, int fromHeight, int toHeight) {
        this.view = view;
        this.originalHeight = fromHeight;
        this.perValue = (toHeight - fromHeight);
    }

    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t) {
        view.getLayoutParams().height = (int) (originalHeight + perValue * interpolatedTime);
        view.requestLayout();
    }

    @Override
    public boolean willChangeBounds() {
        return true;
    }
}

用法:

HeightAnimation heightAnim = new HeightAnimation(view, view.getHeight(), viewPager.getHeight() - otherView.getHeight());
heightAnim.setDuration(1000);
view.startAnimation(heightAnim);

你的思路是对的。确保在动画开始之前将v1设置为布局高度为0。在开始动画之前,您需要初始化您的设置,使其看起来像动画的第一帧。