android - 像 Snapchat-Discover 这样的 Spannable RecyclerView

Question

我正在尝试使用 TwoWayView 库创建一个如下图所示的可跨越式 recyclerView:https://github.com/lucasr/twoway-view

但我无法获得所需的 View ，并且遗漏了一些空单元格。

        final SpannableGridLayoutManager.LayoutParams lp = (SpannableGridLayoutManager.LayoutParams) itemView.getLayoutParams();

        //final int span1 = (itemId == 0 || itemId == 3 ? 2 : 1);
        //final int span2 = (itemId == 0 ? 2 : (itemId == 3 ? 3 : 1));

        int span1 = 0; //h
        int span2 = 0; //w

        switch(itemId)
        {
        case 0:
            span1 = 2;
            span2 = 1;
            break;

        case 1:
            span1 = 2;
            span2 = 1;
            break;

        case 2:
            span1 = 2;
            span2 = 1;
            break;

        case 3:
            span1 = 3;
            span2 = 1;
            break;

        case 4:
            span1 = 3;
            span2 = 1;
            break;

        case 5:
            span1 = 4;
            span2 = 3;
            break;

        case 6:
            span1 = 2;
            span2 = 1;
            break;

        case 7:
            span1 = 2;
            span2 = 1;
            break;

        case 8:
            span1 = 2;
            span2 = 1;
            break;

        case 9:
            span1 = 2;
            span2 = 1;
            break;

        case 10:
            span1 = 4;
            span2 = 3;
            break;
        }

        final int colSpan = span2;
        final int rowSpan = span1;

        if (lp.rowSpan != rowSpan || lp.colSpan != colSpan) 
        {
            lp.rowSpan = rowSpan;
            lp.colSpan = colSpan;
            itemView.setLayoutParams(lp);
        }

XML:

<org.lucasr.twowayview.widget.TwoWayView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/list"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    style="@style/TwoWayView"
    app:twowayview_layoutManager="ListLayoutManager"/>

引用:

编辑 1我能够通过将 XML 中的 rowWidth 更改为 12 和以下跨度来解决此问题:

        //PADDING-- left / top / right / bottom
    switch(itemId%11)
    {
    case 0:
        span1 = 4;
        span2 = 7;
        //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
        break;

    case 1:
        span1 = 4;
        span2 = 7;
        //holder.cont_frienddetail.setPadding(dpAsPixels2, dpAsPixels1, dpAsPixels2, dpAsPixels1);
        break;

    case 2:
        span1 = 4;
        span2 = 7;
        //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
        break;

    case 3:
        span1 = 4;
        span2 = 7;
        //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
        break;

    case 4:
        span1 = 8;
        span2 = 14;
        //holder.cont_frienddetail.setPadding(dpAsPixels2, dpAsPixels1, dpAsPixels0, dpAsPixels1);
        break;

    case 5:
        span1 = 4;
        span2 = 7;
        //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
        break;

    case 6:
        span1 = 6;
        span2 = 10;
        //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels2, dpAsPixels1);
        break;

    case 7:
        span1 = 6;
        span2 = 10;
        //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
        break;

    case 8:
        span1 = 8;
        span2 = 14;
        //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels2, dpAsPixels1);
        break;

    case 9:
        span1 = 4;
        span2 = 7;
        ///holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
        break;

    case 10:
        span1 = 4;
        span2 = 7;
        //holder.cont_frienddetail.setPadding(dpAsPixels0, dpAsPixels1, dpAsPixels0, dpAsPixels1);
        break;
    }

Answer 1

想象一下，使用您的示例图像并将每个单元格的垂直边界延伸到整个屏幕。如果这样做，您会看到有六列。这就是将解决您的问题的洞察力。

现在您可以使用常规的 RecyclerView 和 GridLayoutManager 来完成此操作，而不必依赖于修复 GitHub 库中的所有错误。

创建一个包含 6 列的 GridLayoutManager，然后指定一个自定义 SpanSizeLookup，这将使您的单元格具有不同的宽度。

在您的示例图像中，第一行中的三个单元格将分别跨越 2 列。第二行中两个较大的单元格各跨越 3 列。左下方的单元格跨越 4 列。

现在您所要做的就是创建一个 SpanSizeLookup 来设置正确的宽度。

    // Create a grid layout with 6 columns
    // (least common multiple of 2 and 3)
    GridLayoutManager layoutManager = new GridLayoutManager(this, 6);

    layoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
        @Override
        public int getSpanSize(int position) {

            int widthClass = determineWidth(position) // TODO here you figure out what the cell width should be

            switch (widthClass) {
            case SMALL:
                return 2;   // fits 3 per row

            case MEDIUM:
                return 3;   // fits 2 per row

            case LARGE:     // fits 2 per row, one LARGE and one SMALL
                return 4;

            default:
                throw new IllegalStateException("don\'t know about widthClass " + widthClass);
            }
        }
    });

您可以查看我对类似问题的原始回答here .