RecyclerView takes up all screenspace

问题

So I'm having some trouble with a RecyclerView in a layout file

Here it is:

<android.support.v7.widget.RecyclerView
    android:id="@+id/chat_listview"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:paddingRight="@dimen/abc_action_bar_default_padding_material"
    android:paddingLeft="@dimen/abc_action_bar_default_padding_material"
    />


<LinearLayout
    android:layout_below="@id/chat_listview"
    android:layout_width="match_parent"
    android:layout_height="@dimen/bottom_bar_height"
    android:orientation="horizontal"
    >

    <EditText
        android:id="@+id/chat_input_edittext"
        android:layout_weight="7"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:inputType="textAutoCorrect"
        />

    <Button
        android:id="@+id/chat_send_button"
        android:layout_weight="1"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:background="@drawable/ic_action_send_now"
        />

    </LinearLayout>

The RecyclerView is visible and scrollable but the LinearLayout and the Views inside are not visible... I tried quite a few things but nothing has worked so far.

Can any of you please point me into the right direction?

Many thanks in advance!

回答1:

Change the root view to a FrameLayout. Set the gravity of the LinearLayout to bottom

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">


<android.support.v7.widget.RecyclerView
    android:id="@+id/chat_listview"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingRight="@dimen/abc_action_bar_default_padding_material"
    android:paddingLeft="@dimen/abc_action_bar_default_padding_material"
/>


<LinearLayout
    android:layout_below="@id/chat_listview"
    android:layout_width="match_parent"
    android:layout_height="@dimen/bottom_bar_height"
    android:layout_gravity="bottom"
    android:orientation="horizontal">

    <EditText
        android:id="@+id/chat_input_edittext"
        android:layout_weight="7"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:inputType="textAutoCorrect"/>

    <Button
        android:id="@+id/chat_send_button"
        android:layout_weight="1"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:background="@drawable/ic_action_send_now"/>

    </LinearLayout>
</FrameLayout>

Alternatively, you can wrap the linear layout in a FrameLayout and set it to align_parentBottom = true if it is a relative layout or a linear layout at your root and you have other things in your view.

回答2:

When RecyclerView is drawn, it calculates all the remaining size on screen to itself before drawing the next elements and don't recalculate after the other elements are drawn, leaving them outside the screen.

The trick is to draw all other elements first, and leave RecyclerView for last. FrameLayout does not work anymore so use a relative layout and put the RecyclerView last on the XML layout file.

Example to add a bar with buttons below the RecyclerView:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="16dp"
    tools:context=".MainActivity"
    >

    <LinearLayout
        android:id="@+id/pagination_btns"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:layout_alignParentBottom="true"> //HERE YOU ALIGN THIS ELEMENT TO THE BOTTOM OF THE PARENT
        <Button
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:text="@string/previous_btn_label"/>
        <Space
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"/>
        <Button
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:text="@string/next_btn_label"/>
    </LinearLayout>

    <android.support.v7.widget.RecyclerView
        android:id="@+id/items_recycler_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:scrollbars="vertical"
        android:layout_above="@id/pagination_btns"/> //HERE YOU ALIGN THE RECYCLERVIEW ABOVE THE PAGINATION BAR 


</RelativeLayout>

来源：https://stackoverflow.com/questions/27464073/recyclerview-takes-up-all-screenspace