Question

我有一个名为DogRecyclerView的RecyclerView。我有另一个名为FoodRecyclerView的RecyclerView。 FoodRecyclerView恰好是DogRecyclerView的众多布局之一（即ViewHolder之一）。 DogRecyclerView是一个列表。 FoodRecyclerView实际上如下。问题是下面的视图没有包装内容，而是它的高度超过它应该的高度。我该如何解决这个问题？

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:background="#f00"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <TextView
        android:id="@+id/label"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        tools:text="This is a Label that I am testing right now"/>

    <android.support.v7.widget.RecyclerView
        android:id="@+id/food_grid"
        android:layout_weight="1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
</LinearLayout>

所以你可以看到我撒了一点。嵌套视图实际上是一个包装RecyclerView和TextView的LinearLayout。 DEEE尾巴...

我遗漏了一些非常重要的东西：我的LayoutManager如下：

public class NestedGridLayoutManager extends GridLayoutManager {

    public NestedGridLayoutManager(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
    }

    public NestedGridLayoutManager(Context context, int spanCount) {
        super(context, spanCount);
    }

    public NestedGridLayoutManager(Context context, int spanCount, int orientation, boolean reverseLayout) {
        super(context, spanCount, orientation, reverseLayout);
    }

    private int[] mMeasuredDimension = new int[2];

    @Override
    public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state, int widthSpec, int heightSpec) {
        final int widthMode = View.MeasureSpec.getMode(widthSpec);
        final int heightMode = View.MeasureSpec.getMode(heightSpec);
        final int widthSize = View.MeasureSpec.getSize(widthSpec);
        final int heightSize = View.MeasureSpec.getSize(heightSpec);
        int width = 0;
        int height = 0;
        for (int i = 0; i < getItemCount(); i++) {
            measureScrapChild(recycler, i,
                    View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                    View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                    mMeasuredDimension);

            if (getOrientation() == HORIZONTAL) {
                width = width + mMeasuredDimension[0];
                if (i == 0) {
                    height = mMeasuredDimension[1];
                }
            } else {
                height = height + mMeasuredDimension[1];
                if (i == 0) {
                    width = mMeasuredDimension[0];
                }
            }
        }
        switch (widthMode) {
            case View.MeasureSpec.EXACTLY:
                width = widthSize;
            case View.MeasureSpec.AT_MOST:
            case View.MeasureSpec.UNSPECIFIED:
        }

        switch (heightMode) {
            case View.MeasureSpec.EXACTLY:
                height = heightSize;
            case View.MeasureSpec.AT_MOST:
            case View.MeasureSpec.UNSPECIFIED:
        }

        setMeasuredDimension(width, height);
    }

    private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec,
                                   int heightSpec, int[] measuredDimension) {
        View view = recycler.getViewForPosition(position);
        if (view != null) {
            RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) view.getLayoutParams();
            int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec,
                    getPaddingLeft() + getPaddingRight(), p.width);
            int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec,
                    getPaddingTop() + getPaddingBottom(), p.height);
            view.measure(childWidthSpec, childHeightSpec);
            measuredDimension[0] = view.getMeasuredWidth() + p.leftMargin + p.rightMargin;
            measuredDimension[1] = view.getMeasuredHeight() + p.bottomMargin + p.topMargin;
            recycler.recycleView(view);
        }
    }
}

Answer 1

支持WRAP_CONTENT并且通常会根据其内容自动衡量RecyclerView的大小，这是Support Library 23.2.0 release的标题功能之一。只要您使用包含的LayoutManager，就应该免费获得此行为。

嵌套的RecyclerView太高了

1 个答案: