我应该使用RecyclerView.VERTICAL而不是LinearLayoutManager.VERTICAL吗？

Question

运行./gradlew lint会向我报告一个令人困惑的错误：

39：必须为以下之一：RecyclerView.HORIZONTAL，RecyclerView.VERTICAL

在源代码中：

    38 LinearLayoutManager linearLayoutManager = new LinearLayoutManager(rootView.getContext());
    39 linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
    40 recyclerView.setLayoutManager(linearLayoutManager);
    41 recyclerView.setAdapter(recyclerAdapter);

有什么理由我应该将第39行更改为

linearLayoutManager.setOrientation(RecyclerView.VERTICAL);

Answer 1

使用LinearLayoutManager.VERTICAL或 并没有区别，RecyclerView.VERTICAL 因为LinearLayoutManager它们是相同的。

public class LinearLayoutManager extends RecyclerView.LayoutManager implements
    ItemTouchHelper.ViewDropHandler, RecyclerView.SmoothScroller.ScrollVectorProvider {

private static final String TAG = "LinearLayoutManager";

static final boolean DEBUG = false;

public static final int HORIZONTAL = RecyclerView.HORIZONTAL;

public static final int VERTICAL = RecyclerView.VERTICAL;

如您所见，该代码段来自LinearLayoutManager。

Answer 2

您可以LayoutManager从 XML 布局本身提供：

<android.support.v7.widget.RecyclerView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layoutManager="android.support.v7.widget.LinearLayoutManager" />

或者，您可以通过 Java 代码执行此操作：

LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getContext(), RecyclerView.VERTICAL, false);