Android 以声明方式将宽度分配给可用屏幕宽度的一半

Assign width to half available screen width declaratively

提问by bugzy

Is it possible to assign a widget width to half the available screen width, and do it using declarative xml?

是否可以将小部件宽度分配为可用屏幕宽度的一半，并使用声明性 xml 来实现？

回答by synic

If your widget is a Button:

如果您的小部件是按钮：

<LinearLayout android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:weightSum="2"
    android:orientation="horizontal">
    <Button android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="somebutton"/>

    <TextView android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"/>
</LinearLayout>

I'm assuming you want your widget to take up one half, and another widget to take up the other half. The trick is using a LinearLayout, setting layout_width="fill_parent"on both widgets, and setting layout_weightto the same value on both widgets as well. If there are two widgets, both with the same weight, the LinearLayout will split the width between the two widgets.

我假设您希望您的小部件占据一半，另一个小部件占据另一半。诀窍是使用 LinearLayout，layout_width="fill_parent"在两个小部件上设置，并在两个小部件上设置layout_weight为相同的值。如果有两个小部件，它们的权重相同，则 LinearLayout 将拆分两个小部件之间的宽度。

回答by Suragch

Using constraints layout

使用约束布局

1. Add a Guideline
2. Set the percentage to 50%
3. Constrain your view to the Guideline and the parent.

1. 添加指南
2. 将百分比设置为 50%
3. 将您的视图限制为指南和父级。

If you are having trouble changing it to a percentage, then see this answer.

如果您在将其更改为百分比时遇到问题，请参阅此答案。

XML

XML

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:layout_editor_absoluteX="0dp"
    tools:layout_editor_absoluteY="81dp">

    <android.support.constraint.Guideline
        android:id="@+id/guideline8"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_percent="0.5"/>

    <TextView
        android:id="@+id/textView6"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:text="TextView"
        app:layout_constraintBottom_toTopOf="@+id/guideline8"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

</android.support.constraint.ConstraintLayout>

回答by Rajesh Batth

give width as 0dp to make sure its size is exactly as per its weight this will make sure that even if content of child views get bigger, they'll still be limited to exactly half(according to is weight)

将宽度设为 0dp 以确保其大小与其重量完全一致，这将确保即使子视图的内容变大，它们仍将被限制为恰好一半（根据重量）

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:weightSum="1"
     >

    <Button
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:text="click me"
    android:layout_weight="0.5"/>


    <TextView
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:text="Hello World"
    android:layout_weight="0.5"/>
  </LinearLayout>

回答by Denys_Sh

Another way for single item in center, which fill half of screen:

居中单个项目的另一种方式，填充屏幕的一半：

<LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <View
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:visibility="invisible" />

        <EditText
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="2" />

       <View
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:visibility="invisible" />

</LinearLayout>

回答by Shahzad Shameer

<LinearLayout 
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
    android:id="@+id/textD_Author"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="20dp"
    android:text="Author : "
    android:textColor="#0404B4"
    android:textSize="20sp" />
 <TextView
    android:id="@+id/textD_Tag"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginTop="20dp"
    android:text="Edition : "
    android:textColor="#0404B4"
    android:textSize="20sp" />
<LinearLayout
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="horizontal"
    android:weightSum="1" >
    <Button
        android:id="@+id/btbEdit"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="0.5"
        android:text="Edit" />
    <Button
        android:id="@+id/btnDelete"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="0.5"
        android:text="Delete" />
</LinearLayout>
</LinearLayout>