在 RecyclerView 中向分隔线添加边距

Question

我正在构建一个使用RecyclerView的Android应用程序。我想将分隔符添加到RecyclizerView，我用下面的代码做到了这一点：

DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(recyclerView.getContext(), linearLayoutManager.getOrientation());
recyclerView.addItemDecoration(dividerItemDecoration);

到目前为止，一切正常。然而，分隔线占据了全屏幕的大小，我想给它增加边距。有没有什么方法可以给分隔线添加边距，方法是给绘制的矩形添加一些空间，而不是创建一个带边距的自定义可绘制形状，并将其添加到< code > recycle view 中？

Answer 1

使用它并根据您的要求进行自定义。

public class DividerItemDecoration extends RecyclerView.ItemDecoration {

    private static final int[] ATTRS = new int[]{android.R.attr.listDivider};

    private Drawable divider;

    /**
     * Default divider will be used
     */
    public DividerItemDecoration(Context context) {
        final TypedArray styledAttributes = context.obtainStyledAttributes(ATTRS);
        divider = styledAttributes.getDrawable(0);
        styledAttributes.recycle();
    }

    /**
     * Custom divider will be used
     */
    public DividerItemDecoration(Context context, int resId) {
        divider = ContextCompat.getDrawable(context, resId);
    }

    @Override
    public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
        int left = parent.getPaddingLeft();
        int right = parent.getWidth() - parent.getPaddingRight();

        int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++) {
            View child = parent.getChildAt(i);

            RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();

            int top = child.getBottom() + params.bottomMargin;
            int bottom = top + divider.getIntrinsicHeight();

            divider.setBounds(left, top, right, bottom);
            divider.draw(c);
        }
    }
}

Answer 2

shape.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <solid android:color="#E6E7F0" />
    <size android:height="1dp" />
</shape>

layer.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:drawable="@drawable/shape"
        android:left="16dp"
        android:right="16dp" />

</layer-list>

法典

val itemDecoration = DividerItemDecoration(context, DividerItemDecoration.VERTICAL)
itemDecoration.setDrawable(resources.getDrawable(R.drawable.layer, null))
recyclerView.addItemDecoration(itemDecoration)

Answer 3

我认为最简单的解决方案是在装饰对象上使用setDrawable方法，并向其传递一个inset drawable，其中包含您希望用于边距的inset值。像这样：

int[] ATTRS = new int[]{android.R.attr.listDivider};

TypedArray a = context.obtainStyledAttributes(ATTRS);
Drawable divider = a.getDrawable(0);
int inset = getResources().getDimensionPixelSize(R.dimen.your_margin_value);
InsetDrawable insetDivider = new InsetDrawable(divider, inset, 0, inset, 0);
a.recycle();

DividerItemDecoration itemDecoration = new DividerItemDecoration(context, DividerItemDecoration.VERTICAL);
itemDecoration.setDrawable(insetDivider);
recyclerView.addItemDecoration(itemDecoration);