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

另一种选择是使用以下缩放因子的缩放动画进行扩展:

ScaleAnimation anim = new ScaleAnimation(1, 1, 0, 1);

至于坍塌:

ScaleAnimation anim = new ScaleAnimation(1, 1, 1, 0);

其他回答

平滑动画请使用Handler运行方法.....享受展开/折叠动画

    class AnimUtils{

                 public void expand(final View v) {
                  int ANIMATION_DURATION=500;//in milisecond
        v.measure(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
        final int targtetHeight = v.getMeasuredHeight();

        v.getLayoutParams().height = 0;
        v.setVisibility(View.VISIBLE);
        Animation a = new Animation()
        {
            @Override
            protected void applyTransformation(float interpolatedTime, Transformation t) {
                v.getLayoutParams().height = interpolatedTime == 1
                        ? LayoutParams.WRAP_CONTENT
                        : (int)(targtetHeight * interpolatedTime);
                v.requestLayout();
            }

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

        // 1dp/ms
        a.setDuration(ANIMATION_DURATION);

      // a.setDuration((int)(targtetHeight / v.getContext().getResources().getDisplayMetrics().density));
        v.startAnimation(a);
    }



    public void collapse(final View v) {
        final int initialHeight = v.getMeasuredHeight();

        Animation a = new Animation()
        {
            @Override
            protected void applyTransformation(float interpolatedTime, Transformation t) {
                if(interpolatedTime == 1){
                    v.setVisibility(View.GONE);
                }else{
                    v.getLayoutParams().height = initialHeight - (int)(initialHeight * interpolatedTime);
                    v.requestLayout();
                }
            }

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

        // 1dp/ms
        a.setDuration(ANIMATION_DURATION);
       // a.setDuration((int)(initialHeight / v.getContext().getResources().getDisplayMetrics().density));
        v.startAnimation(a);
    }
}

使用下面的代码调用:

       private void setAnimationOnView(final View inactive ) {
    //I am applying expand and collapse on this TextView ...You can use your view 

    //for expand animation
    new Handler().postDelayed(new Runnable() {
        @Override
        public void run() {

            new AnimationUtililty().expand(inactive);

        }
    }, 1000);


    //For collapse
    new Handler().postDelayed(new Runnable() {
        @Override
        public void run() {

            new AnimationUtililty().collapse(inactive);
            //inactive.setVisibility(View.GONE);

        }
    }, 8000);

}

其他解决方案是:

               public void expandOrCollapse(final View v,String exp_or_colpse) {
    TranslateAnimation anim = null;
    if(exp_or_colpse.equals("expand"))
    {
        anim = new TranslateAnimation(0.0f, 0.0f, -v.getHeight(), 0.0f);
        v.setVisibility(View.VISIBLE);  
    }
    else{
        anim = new TranslateAnimation(0.0f, 0.0f, 0.0f, -v.getHeight());
        AnimationListener collapselistener= new AnimationListener() {
            @Override
            public void onAnimationStart(Animation animation) {
            }

            @Override
            public void onAnimationRepeat(Animation animation) {
            }

            @Override
            public void onAnimationEnd(Animation animation) {
            v.setVisibility(View.GONE);
            }
        };

        anim.setAnimationListener(collapselistener);
    }

     // To Collapse
        //

    anim.setDuration(300);
    anim.setInterpolator(new AccelerateInterpolator(0.5f));
    v.startAnimation(anim);
}
/**
 * Animation that either expands or collapses a view by sliding it down to make
 * it visible. Or by sliding it up so it will hide. It will look like it slides
 * behind the view above.
 * 
 */
public class FinalExpandCollapseAnimation extends Animation
{
    private View mAnimatedView;
    private int mEndHeight;
    private int mType;
    public final static int COLLAPSE = 1;
    public final static int EXPAND = 0;
    private LinearLayout.LayoutParams mLayoutParams;
    private RelativeLayout.LayoutParams mLayoutParamsRel;
    private String layout;
    private Context context;

    /**
     * Initializes expand collapse animation, has two types, collapse (1) and
     * expand (0).
     * 
     * @param view
     *            The view to animate
     * @param type
     *            The type of animation: 0 will expand from gone and 0 size to
     *            visible and layout size defined in xml. 1 will collapse view
     *            and set to gone
     */
    public FinalExpandCollapseAnimation(View view, int type, int height, String layout, Context context)
    {
        this.layout = layout;
        this.context = context;
        mAnimatedView = view;
        mEndHeight = mAnimatedView.getMeasuredHeight();
        if (layout.equalsIgnoreCase("linear"))
            mLayoutParams = ((LinearLayout.LayoutParams) view.getLayoutParams());
        else
            mLayoutParamsRel = ((RelativeLayout.LayoutParams) view.getLayoutParams());
        mType = type;
        if (mType == EXPAND)
        {
            AppConstant.ANIMATED_VIEW_HEIGHT = height;
        }
        else
        {
            if (layout.equalsIgnoreCase("linear"))
                mLayoutParams.topMargin = 0;
            else
                mLayoutParamsRel.topMargin = convertPixelsIntoDensityPixels(36);
        }
        setDuration(600);
    }

    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t)
    {
        super.applyTransformation(interpolatedTime, t);
        if (interpolatedTime < 1.0f)
        {
            if (mType == EXPAND)
            {
                if (layout.equalsIgnoreCase("linear"))
                {
                    mLayoutParams.height = AppConstant.ANIMATED_VIEW_HEIGHT
                            + (-AppConstant.ANIMATED_VIEW_HEIGHT + (int) (AppConstant.ANIMATED_VIEW_HEIGHT * interpolatedTime));
                }
                else
                {
                    mLayoutParamsRel.height = AppConstant.ANIMATED_VIEW_HEIGHT
                            + (-AppConstant.ANIMATED_VIEW_HEIGHT + (int) (AppConstant.ANIMATED_VIEW_HEIGHT * interpolatedTime));
                }
                mAnimatedView.setVisibility(View.VISIBLE);
            }
            else
            {
                if (layout.equalsIgnoreCase("linear"))
                    mLayoutParams.height = mEndHeight - (int) (mEndHeight * interpolatedTime);
                else
                    mLayoutParamsRel.height = mEndHeight - (int) (mEndHeight * interpolatedTime);
            }
            mAnimatedView.requestLayout();
        }
        else
        {
            if (mType == EXPAND)
            {
                if (layout.equalsIgnoreCase("linear"))
                {
                    mLayoutParams.height = AppConstant.ANIMATED_VIEW_HEIGHT;
                    mLayoutParams.topMargin = 0;
                }
                else
                {
                    mLayoutParamsRel.height = AppConstant.ANIMATED_VIEW_HEIGHT;
                    mLayoutParamsRel.topMargin = convertPixelsIntoDensityPixels(36);
                }
                mAnimatedView.setVisibility(View.VISIBLE);
                mAnimatedView.requestLayout();
            }
            else
            {
                if (layout.equalsIgnoreCase("linear"))
                    mLayoutParams.height = 0;
                else
                    mLayoutParamsRel.height = 0;
                mAnimatedView.setVisibility(View.GONE);
                mAnimatedView.requestLayout();
            }
        }
    }

    private int convertPixelsIntoDensityPixels(int pixels)
    {
        DisplayMetrics metrics = context.getResources().getDisplayMetrics();
        return (int) metrics.density * pixels;
    }
}

该类可以通过以下方式调用

   if (findViewById(R.id.ll_specailoffer_show_hide).getVisibility() == View.VISIBLE) {
                        ((ImageView) findViewById(R.id.iv_specialhour_seemore)).setImageResource(R.drawable.white_dropdown_up);

                        FinalExpandCollapseAnimation finalExpandCollapseAnimation = new FinalExpandCollapseAnimation(
                                findViewById(R.id.ll_specailoffer_show_hide),
                                FinalExpandCollapseAnimation.COLLAPSE,
                                SpecialOfferHeight, "linear", this);
                        findViewById(R.id.ll_specailoffer_show_hide)
                                .startAnimation(finalExpandCollapseAnimation);
                        ((View) findViewById(R.id.ll_specailoffer_show_hide).getParent()).invalidate();
                    } else {
                        ((ImageView) findViewById(R.id.iv_specialhour_seemore)).setImageResource(R.drawable.white_dropdown);

                        FinalExpandCollapseAnimation finalExpandCollapseAnimation = new FinalExpandCollapseAnimation(
                                findViewById(R.id.ll_specailoffer_show_hide),
                                FinalExpandCollapseAnimation.EXPAND,
                                SpecialOfferHeight, "linear", this);
                        findViewById(R.id.ll_specailoffer_show_hide)
                                .startAnimation(finalExpandCollapseAnimation);
                        ((View) findViewById(R.id.ll_specailoffer_show_hide).getParent()).invalidate();
                    }

我想对上面非常有用的答案补充一些东西。如果你不知道你最终得到的高度,因为你的views .getHeight()返回0,你可以做下面的事情来获得高度:

contentView.measure(DUMMY_HIGH_DIMENSION, DUMMY_HIGH_DIMENSION);
int finalHeight = view.getMeasuredHeight();

其中DUMMY_HIGH_DIMENSIONS是宽度/高度(以像素为单位),您的视图被限制为…当视图被ScrollView封装时,有这么大的数字是合理的。

我创建的版本中,你不需要指定布局高度,因此它更容易和更干净的使用。解决方案是在动画的第一帧中获取高度(至少在我的测试中是可用的)。通过这种方式,您可以为视图提供任意高度和底边距。

在构造函数中还有一个小hack -底部边距被设置为-10000,以便视图在转换之前保持隐藏(防止闪烁)。

public class ExpandAnimation extends Animation {


    private View mAnimatedView;
    private ViewGroup.MarginLayoutParams mViewLayoutParams;
    private int mMarginStart, mMarginEnd;

    public ExpandAnimation(View view) {
        mAnimatedView = view;
        mViewLayoutParams = (ViewGroup.MarginLayoutParams) view.getLayoutParams();
        mMarginEnd = mViewLayoutParams.bottomMargin;
        mMarginStart = -10000; //hide before viewing by settings very high negative bottom margin (hack, but works nicely)
        mViewLayoutParams.bottomMargin = mMarginStart;
        mAnimatedView.setLayoutParams(mViewLayoutParams);
    }

    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t) {
        super.applyTransformation(interpolatedTime, t);
            //view height is already known when the animation starts
            if(interpolatedTime==0){
                mMarginStart = -mAnimatedView.getHeight();
            }
            mViewLayoutParams.bottomMargin = (int)((mMarginEnd-mMarginStart) * interpolatedTime)+mMarginStart;
            mAnimatedView.setLayoutParams(mViewLayoutParams);
    }
}

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);