Question

我正在使用RecyclerView为Robolectric个项目编写测试用例。在调用recyclerView.measure(0,0)时面对NullPointerException，因为RecyclerView已应用RecyclerView.ItemDecoration，但RecyclerView与RecyclerView.ItemDecoration无关。

异常日志：

java.lang.NullPointerException
    at ui.adapters.DividerItemDecoration.getItemOffsets(DividerItemDecoration.java:119)
    at android.support.v7.widget.RecyclerView$ItemDecoration.getItemOffsets(RecyclerView.java:8662)

在DividerItemDecoration.java的第119行放置了评论，此处mDivider变为NULL，它是从构造函数初始化的。

@Override
    public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {
        if (mOrientation == VERTICAL_LIST) {
            outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());//Line:119
        } else {
            outRect.set(0, 0, mDivider.getIntrinsicWidth(), 0);
        }
    }

构造

public DividerItemDecoration(Context context, int orientation) {
        final TypedArray a = context.obtainStyledAttributes(ATTRS);
        mDivider = a.getDrawable(0);
        a.recycle();
        setOrientation(orientation);
    }

ATTRS

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

请提前告知我如何编写RecyclerView RecyclerView.ItemDecoration的测试用例，并提前感谢。

解：最后，我通过为Shadow创建RecyclerView类来解决此问题，如下面的代码所述，并遵循基本的阴影映射逻辑，

RecyclerViewShadow.java

@Implements(RecyclerView.class)
public class RecyclerViewShadow extends ShadowViewGroup {
    @Implementation
    public void addItemDecoration(RecyclerView.ItemDecoration decor, int index) {

    }
}

Rebolectric：DividerItemDecoration阻止将测量设置为recyclerview

0 个答案: