更改 RecyclerView 网格布局中的列数

Question

我正在尝试根据显示大小更改回收站视图（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 根据屏幕尺寸的变化（在方向期间）更改列数。因此，如果应用程序以纵向模式打开，则（在手机上）它决定为一列，这看起来不错，但是当应用程序直接以横向模式打开时，此方法不起作用，其中网格中有一张拉伸的卡片显示在屏幕上。

这里的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();

最好的问候

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

如果您提供固定的列宽，您可以扩展RecyclerView 并在onMeasure 中相应地设置跨度计数：

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);
  }
}

查看我的博文了解更多信息： http://blog.sqisland.com/2014/12/recyclerview-autofit-grid.html

Answer 3

这是我的解决方案。

public class ResponsiveGridLayoutManager extends GridLayoutManager {
    boolean hasSetupColumns;
    int columnWidthPx;

    public ResponsiveGridLayoutManager(Context context, int orientation,
        boolean reverseLayout, int columnWidthUnit, float columnWidth) {

        super(context, 1, orientation, reverseLayout);

        Resources r;
        if (context == null) {
            r = Resources.getSystem();
        } else {
            r = context.getResources();
        }

        float colWidthPx = TypedValue.applyDimension(columnWidthUnit,
            columnWidth, r.getDisplayMetrics());

        this.columnWidthPx = Math.round(colWidthPx);
    }

    public ResponsiveGridLayoutManager(Context context, AttributeSet attrs,
        int defStyleAttr, int defStyleRes) {

        super(context, attrs, defStyleAttr, defStyleRes);
        int[] requestedValues = {
            android.R.attr.columnWidth,
        };

        TypedArray a = context.obtainStyledAttributes(attrs, requestedValues);
        this.columnWidthPx = a.getDimensionPixelSize(0, -1);
        a.recycle();
    }

    @Override
    public int getWidth() {
        int width = super.getWidth();
        if (!hasSetupColumns && width > 0) {
            this.setSpanCount((int)Math.floor(width / this.columnWidthPx));
        }

        return width;
    }
}

您可以将它与 XML 一起使用：

<android.support.v7.widget.RecyclerView
    android:id="@+id/recycler"
    android:scrollbars="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"

    app:layoutManager="com.caff.localflix.ResponsiveGridLayoutManager"
    android:columnWidth="148dp" />

或Java：

ResponsiveGridLayoutManager layoutManager = new ResponsiveGridLayoutManager(
    this,
    GridLayoutManager.VERTICAL,
    false,
    TypedValue.COMPLEX_UNIT_DIP,
    148f
);

Answer 4

您可以创建一个依赖于屏幕的资源文件并加载它。例如 values-w820p 文件夹中的 booleans.xml。或者可能只是为大屏幕创建一个布局并完成它。