更改RecyclerView gridlayout中的列数

Question

我正在尝试根据显示大小更改回收器视图(网格布局)中显示的列数.但是我无法找到实现它的正确方法.目前我正在使用treeViewObserver根据屏幕大小的变化(在定向期间)更改列数.因此,如果应用程序以纵向模式打开,列数(在手机上)它决定为一个,看起来不错,但当应用程序直接以横向模式打开时,此方法不起作用,其中网格中有单个拉出的卡片显示在屏幕上.

这里recList是RecyclerView&glm是RecyclerView中使用的GridLayoutManager

    viewWidth = recList.getMeasuredWidth();

    cardViewWidthZZ = recList.getChildAt(0).getMeasuredWidth();

    if (oldWidth == 0) {
        oldWidth = cardViewWidthZZ;
    }

    if (oldWidth <= 0)
        return;

    int newSpanCount = (int) Math.floor(viewWidth / (oldWidth / 1.3f));
    if (newSpanCount <= 0)
        newSpanCount = 1;
    glm.setSpanCount(newSpanCount);
    glm.requestLayout();

最好的祝福

Answer 1

public class VarColumnGridLayoutManager extends GridLayoutManager {

private int minItemWidth;

public VarColumnGridLayoutManager(Context context, int minItemWidth) {
    super(context, 1);
    this.minItemWidth = minItemWidth;
}

@Override
public void onLayoutChildren(RecyclerView.Recycler recycler,
        RecyclerView.State state) {
    updateSpanCount();
    super.onLayoutChildren(recycler, state);
}

private void updateSpanCount() {
    int spanCount = getWidth() / minItemWidth;
    if (spanCount < 1) {
        spanCount = 1;
    }
    this.setSpanCount(spanCount);
}}

Answer 2

如果提供固定的列宽,则可以相应地扩展RecyclerView和设置跨度计数onMeasure:

public AutofitRecyclerView(Context context, AttributeSet attrs) {
  super(context, attrs);

  if (attrs != null) {
    // Read android:columnWidth from xml
    int[] attrsArray = {
        android.R.attr.columnWidth
    };
    TypedArray array = context.obtainStyledAttributes(attrs, attrsArray);
    columnWidth = array.getDimensionPixelSize(0, -1);
    array.recycle();
  }

  manager = new GridLayoutManager(getContext(), 1);
  setLayoutManager(manager);
}

protected void onMeasure(int widthSpec, int heightSpec) {
  super.onMeasure(widthSpec, heightSpec);
  if (columnWidth > 0) {
    int spanCount = Math.max(1, getMeasuredWidth() / columnWidth);
    manager.setSpanCount(spanCount);
  }
}

有关详细信息,请参阅我的博文:http: //blog.sqisland.com/2014/12/recyclerview-autofit-grid.html