Android 列表项上的滑动菜单无法处理父宽度更改

Question

我正在尝试为我在 recyclerview 中的项目创建滑动菜单并最终实现了库：https://github.com/chthai64/SwipeRevealLayout

实施后初看，还以为可以呢。但出于某种原因，当父级 view/layout（包含片段的框架布局）发生变化时，它 change/measure/layout 项目的正确宽度不正确。

该项目只是保持相同的宽度，太宽或太短，具体取决于父视图的缩放方式。

我已经从库中的自定义视图 "SwipeRevealLayout" 中包含了 onMeasure 方法。

@Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        if (getChildCount() < 2) {
            throw new RuntimeException("Layout must have two children");
        }

        final LayoutParams params = getLayoutParams();

        final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
        final int heightMode = MeasureSpec.getMode(heightMeasureSpec);

        int desiredWidth = 0;
        int desiredHeight = 0;

        // first find the largest child
        for (int i = 0; i < getChildCount(); i++) {
            final View child = getChildAt(i);
            measureChild(child, widthMeasureSpec, heightMeasureSpec);
            desiredWidth = Math.max(child.getMeasuredWidth(), desiredWidth);
            desiredHeight = Math.max(child.getMeasuredHeight(), desiredHeight);
        }

        // create new measure spec using the largest child width
        widthMeasureSpec = MeasureSpec.makeMeasureSpec(desiredWidth, widthMode);
        heightMeasureSpec = MeasureSpec.makeMeasureSpec(desiredHeight, heightMode);

        final int measuredWidth = MeasureSpec.getSize(widthMeasureSpec);
        final int measuredHeight = MeasureSpec.getSize(heightMeasureSpec);

        for (int i = 0; i < getChildCount(); i++) {
            final View child = getChildAt(i);
            final LayoutParams childParams = child.getLayoutParams();

            if (childParams != null) {
                if (childParams.height == LayoutParams.MATCH_PARENT) {
                    child.setMinimumHeight(measuredHeight);
                }

                if (childParams.width == LayoutParams.MATCH_PARENT) {
                    child.setMinimumWidth(measuredWidth);
                }
            }

            measureChild(child, widthMeasureSpec, heightMeasureSpec);
            desiredWidth = Math.max(child.getMeasuredWidth(), desiredWidth);
            desiredHeight = Math.max(child.getMeasuredHeight(), desiredHeight);
        }

        // taking accounts of padding
        desiredWidth += getPaddingLeft() + getPaddingRight();
        desiredHeight += getPaddingTop() + getPaddingBottom();

        // adjust desired width
        if (widthMode == MeasureSpec.EXACTLY) {
            desiredWidth = measuredWidth;
        } else {
            if (params.width == LayoutParams.MATCH_PARENT) {
                desiredWidth = measuredWidth;
            }

            if (widthMode == MeasureSpec.AT_MOST) {
                desiredWidth = (desiredWidth > measuredWidth)? measuredWidth : desiredWidth;
            }
        }

        // adjust desired height
        if (heightMode == MeasureSpec.EXACTLY) {
            desiredHeight = measuredHeight;
        } else {
            if (params.height == LayoutParams.MATCH_PARENT) {
                desiredHeight = measuredHeight;
            }

            if (heightMode == MeasureSpec.AT_MOST) {
                desiredHeight = (desiredHeight > measuredHeight)? measuredHeight : desiredHeight;
            }
        }

        setMeasuredDimension(desiredWidth, desiredHeight);
    }

我在其他地方找到了部分解决方案，项目的所有内容都已正确缩放。我用下面的代码替换了 onMeasure 中的所有代码。然而，这个解决方案有一个副作用，即项目被完全擦出屏幕，而不是在滑动菜单的按钮之前停止。

super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        setMeasuredDimension(getMeasuredWidth(), getMeasuredWidth() / 2);
        // this is required because the children keep the super class calculated dimensions (which will not work with the new MyFrameLayout sizes)
        final int count = getChildCount();
        for (int i = 0; i < count; i++) {
            final View v = getChildAt(i);

            v.measure(MeasureSpec.makeMeasureSpec(getMeasuredWidth(),
                    MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(
                    getMeasuredHeight(), MeasureSpec.EXACTLY));
        }

Answer 1

没关系:)我终于通过在onMeasure中操纵项目的宽度解决了这个问题。这对我来说很完美。也许其他人可以使用它。我所做的是检查第一个子项是否比我允许的宽（比父视图宽），如果是，则将其设置为最大宽度。如果其他子视图（例如列表中的项目）的 width/measured 宽度不等于父视图宽度，我将子视图设置为此。

这里是onMeasure的顶部，我稍微改了一下。

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    if (getChildCount() < 2) {
        throw new RuntimeException("Layout must have two children");
    }
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);

    final LayoutParams params = getLayoutParams();

    final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
    final int heightMode = MeasureSpec.getMode(heightMeasureSpec);

    int maxWidth        = getMeasuredWidth();
    int desiredWidth    = 0;
    int desiredHeight   = 0;

    // first find the largest child
    for (int i = 0; i < getChildCount(); i++) {
        final View child = getChildAt(i);
        if (i == 0 && (child.getWidth() > maxWidth || child.getMeasuredWidth() > maxWidth)
            || i > 0 && (child.getWidth() != maxWidth || child.getMeasuredWidth() != maxWidth)) {
            LayoutParams lm = child.getLayoutParams();
            lm.width        = maxWidth;
            child.setLayoutParams(lm);
        }
        measureChild(child, widthMeasureSpec, heightMeasureSpec);
        desiredWidth = Math.max(child.getMeasuredWidth(), desiredWidth);
        desiredHeight = Math.max(child.getMeasuredHeight(), desiredHeight);
    }

...

Android 列表项上的滑动菜单无法处理父宽度更改

Android Swipe menu on list item can't handle parent width changes

android

onmeasure