android - 如何设置 RecyclerView 应用程序 :layoutManager ="" from XML?

Question

如何设置RecyclerView来自 XML 的布局管理器？

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

Answer 1

您可以查看文档:

Class name of the Layout Manager to be used.

The class must extend androidx.recyclerview.widget.RecyclerViewView$LayoutManager and have either a default constructor or constructor with the signature (android.content.Context, android.util.AttributeSet, int, int)

If the name starts with a '.', application package is prefixed. Else, if the name contains a '.', the classname is assumed to be a full class name. Else, the recycler view package (androidx.appcompat.widget) is prefixed

使用 androidx，您可以使用:

<androidx.recyclerview.widget.RecyclerView
     xmlns:app="http://schemas.android.com/apk/res-auto"
     app:layoutManager="androidx.recyclerview.widget.GridLayoutManager">

通过支持库，您可以使用:

<android.support.v7.widget.RecyclerView
    xmlns:app="http://schemas.android.com/apk/res-auto"
    app:layoutManager="android.support.v7.widget.GridLayoutManager" >

您还可以添加以下属性:

• android:orientation = "horizo​​ntal|vertical":控制LayoutManager的方向(eg:LinearLayoutManager)
• app:spanCount:设置GridLayoutManager
的列数

例子:

<androidx.recyclerview.widget.RecyclerView
    app:layoutManager="androidx.recyclerview.widget.GridLayoutManager"
    app:spanCount="2"
    ...>

或:

<androidx.recyclerview.widget.RecyclerView
    app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
    android:orientation="vertical"
    ...>

您也可以使用 tools 命名空间(即 tools:orientation 和 tools:layoutManager)添加它们然后它只会影响 IDE 预览，您可以继续在代码中设置这些值。