设置高度视图以匹配父级与android中的动画答案

【问题标题】：set height view to match parent with animation in android设置高度视图以匹配父级与android中的动画
【发布时间】：2017-04-07 18:27:10
【问题描述】：

当有点击时如何将view的高度改为match_parent？

public class ResizeAnimation extends Animation {
    final int startHeight;
    final int targetHeight;
    private final boolean isOpen;
    View view;

    public ResizeAnimation(View view, int height, boolean isOpen) {
        this.view = view;
        this.targetHeight = height;
        this.isOpen = isOpen;
        startHeight = view.getHeight();
    }

    @Override
     protected void applyTransformation(float interpolatedTime, Transformation t) {
        int newHeight;
        if (isOpen) {
            newHeight = (int) (startHeight + (targetHeight - startHeight) * interpolatedTime);
        } else {
            newHeight =  (int) (startHeight + targetHeight * interpolatedTime);
        }
        view.getLayoutParams().height = newHeight;
        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;
    }
}

ResizeAnimation resizeAnimation = new ResizeAnimation(view, MATCH_PARENT, false);
resizeAnimation.setDuration(500);
view.startAnimation(resizeAnimation);

【问题讨论】：

标签： java android xml animation android-linearlayout

【解决方案1】：

您的动画不起作用，因为您将 View.MATCH_PARENT（其值为 -1）作为目标高度传递。引用文档：

int MATCH_PARENT [...] 常数值：-1 (0xffffffff)

你必须通过真实的目标高度。您可以在父布局渲染后测量其未来的目标高度（为此我推荐您ViewTreeObserver.onGlobalLayout()）。

【讨论】：