我有一个线性布局一个按钮。我希望按钮占用其父宽度的一半。有没有办法做到这一点在布局XML。

I have a single button in a linear layout. I want the button to take up half the width of its parent. Is there a way to do this in the layout xml.

<LinearLayout
    android:id="@+id/linearLayout1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:gravity="center_horizontal"
    android:padding="6dp">

    <Button
        android:id="@+id/buttonCollect"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:text="@string/hello"
        android:paddingLeft="8dp"
        android:paddingRight="8dp"/>

</LinearLayout> 

我的问题是很多像这样的指定宽度的一半可用屏幕宽度的声明，除了我只有一个按钮。

My question is much like this one Assign width to half available screen width declaratively except I only have a single button.

推荐答案

是的，解决方法是非常相似的问题，但你也想设置父的LinearLayout的weightSum：

Yep, the solution is very similar to that question, but you also want to set the weightSum of the parent LinearLayout:

<LinearLayout
    android:id="@+id/linearLayout1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:gravity="center_horizontal"
    android:padding="6dp"
    android:weightSum="2">

    <Button
        android:id="@+id/buttonCollect"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:text="@string/hello"
        android:paddingLeft="8dp"
        android:paddingRight="8dp"
        android:layout_weight="1" />

</LinearLayout>