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Android ConstraintLayout垂直文本视图对齐

android-constraintlayout android

SMGhost · 技术社区 · 6 年前

我有以下布局:

<?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:id="@+id/dishContainer"
    android:layout_width="match_parent"
    android:layout_height="100dp"
    android:background="#0ff"
    android:clickable="true"
    android:focusable="true">

    <TextView
        android:id="@+id/one"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginEnd="16dp"
        android:maxLines="3"
        android:background="#ff0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:text="One line lsfdjslkdf jksdljsdkljf sklksf klsjklsksjskfljsaklfj slkjfslkjfdskljfalskjflksdajfaklsjksadljfksfjksjkslfjsljsk lskjslksj ks flks jklsfjsl lsk slk" />

    <TextView
        android:id="@+id/two"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="#0f0"
        app:layout_constraintStart_toStartOf="@+id/one"
        app:layout_constraintTop_toBottomOf="@+id/one"
        app:layout_constraintBottom_toTopOf="@+id/three"
        tools:text="Two kksldfj lskfd lksd jlkfsd jksld ksldfj sdlks dklfklsffsd klsdfjklsdf kdsflkj skldfsf sdfksdjf jsdfsjklfklskfls fklsf jklsdfjksf lksjdflk sdklsf lksfdjkls fk" />

    <TextView
        android:id="@+id/three"
        android:layout_width="wrap_content"
        android:background="#f00"
        android:lines="1"
        android:layout_height="wrap_content"
        app:layout_constraintStart_toStartOf="@+id/two"
        app:layout_constraintTop_toBottomOf="@+id/two"
        app:layout_constraintBottom_toBottomOf="parent"
        tools:text="Third text that dissapears, but should not go below the parent" />

</android.support.constraint.ConstraintLayout>

问题是,绿色textview占用了太多空间,忽略了顶部和底部约束。如果我将绿色文本视图高度设置为0dp 我明白了:

这几乎是我想要的,但如果我只有很少的文字,我会得到:

在这里,我的红色文本视图留在底部,即使绿色文本视图有足够的空间缩小并让红色文本视图上升。

基本上,我希望我的红色视图总是低于绿色视图,但是当红色到达父窗口的底部时,它应该停止在那里,同时也阻止绿色文本视图的扩展。

我怎样才能做到这一点?

0 回复 | 直到 6 年前

Ferran 6 年前

试试这个

(我将布局宽度设置为与父级匹配…,如果需要,可以更改它)

<?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:orientation="vertical"
    android:paddingEnd="16dp"
    android:paddingStart="16dp"
    android:layout_width="match_parent"
    android:layout_height="100dp">

    <TextView
        android:id="@+id/one"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:maxLines="3"
        android:background="#ff0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:text="One line lsfdjslkdf jksdljsdkljf sklksf klsjklsksjskfljsaklfj slkjfslkjfdskljfalskjflksdajfaklsjksadljfksfjksjkslfjsljsk lskjslksj ks flks jklsfjsl lsk slk" />

    <TextView
        android:id="@+id/two"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#0f0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/one"
        app:layout_constraintBottom_toTopOf="@id/three"
        app:layout_constrainedHeight="true"
        tools:text="Two kksldfj lskfd lksd jlkfsd jksld ksldfj sdlks dklfklsffsd klsdfjklsdf kdsflkj skldfsf sdfksdjf jsdfsjklfklskfls fklsf jklsdfjksf lksjdflk sdklsf lksfdjkls fk" />

    <TextView
        android:id="@+id/three"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:background="#f00"
        android:lines="1"
        app:layout_constraintHeight_min="20dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/two"
        app:layout_constraintBottom_toBottomOf="parent"
        tools:text="Third text that dissapears, but should not go below the parent" />

</android.support.constraint.ConstraintLayout>

user11566289user11566289 6 年前

当接受的答案起作用时,我注意到底部的高度 TextView 将展开以填充容器的剩余垂直空间。

借助于 Guideline ,我们可以给出 文本视图 一个固定的高度,不管它是否有空间膨胀。

dimens.xml文件

<dimen name="bottom_view_height">20dp</dimen>

布局.xml

<androidx.constraintlayout.widget.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">

    <TextView
        android:id="@+id/green"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#4CAF50"
        android:maxLines="3"
        app:layout_constraintTop_toTopOf="parent"
        tools:text="@tools:sample/lorem/random"/>

    <TextView
        android:id="@+id/yellow"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#FFEB3B"
        app:layout_constrainedHeight="true"
        app:layout_constraintTop_toBottomOf="@id/green"
        app:layout_constraintBottom_toTopOf="@id/bottom_guide"
        app:layout_constraintVertical_bias="0"
        tools:text="@tools:sample/lorem/random"
        tools:lines="100"/>

    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/bottom_guide"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_end="@dimen/bottom_view_height"/>

    <TextView
        android:id="@+id/red"
        android:layout_width="match_parent"
        android:layout_height="@dimen/bottom_view_height"
        android:background="#F44336"
        app:layout_constraintTop_toBottomOf="@id/yellow"
        tools:text="@tools:sample/lorem/random"/>

</androidx.constraintlayout.widget.ConstraintLayout>

工作原理

这个 指南 作为中间层的底部约束 文本视图 ,它通过 layout_constraintVertical_bias="0" 是的。

设置 layout_constrainedHeight="true" 在中间的textview确保它不会超出指导原则。这反过来又确保底部的文本视图永远不会离开屏幕。

Mark 6 年前

我会把 app:layout_constraintBottom_toTopOf="@+id/three" 对textview 2的限制,不需要它,这可能是您看到第二个textview占用额外空间的原因。

Rajasekaran M 6 年前

如果内容是动态的,则不应使用静态高度值。如果以线性方式分配视图,则不要在约束布局中对齐底部的视图

 <?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:id="@+id/dishContainer"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="#0ff"
    android:paddingTop="8dp"
    android:paddingBottom="8dp"
    android:clickable="true"
    android:focusable="true">

    <TextView
        android:id="@+id/one"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginEnd="16dp"
        android:background="#ff0"
        android:maxLines="3"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:text="One line lsfdjslkdf jksdljsdkljf sklksf klsjklsksjskfljsaklfj slkjfslkjfdskljfalskjflksdajfaklsjksadljfksfjksjkslfjsljsk lskjslksj ks flks jklsfjsl lsk slk" />

    <TextView
        android:id="@+id/two"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:background="#0f0"
        app:layout_constraintEnd_toEndOf="@+id/one"
        app:layout_constraintStart_toStartOf="@+id/one"
        app:layout_constraintTop_toBottomOf="@+id/one"
        tools:text="Two kksldfj lskfd lksd jlkfsd jksld ksldfj sdlks dklfklsffsd klsdfjklsdf kdsflkj skldfsf sdfksdjf jsdfsjklfklskfls fklsf jklsdfjksf lksjdflk sdklsf lksfdjkls fk" />

    <TextView
        android:id="@+id/three"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:background="#f00"
        android:lines="1"
        app:layout_constraintEnd_toEndOf="@+id/one"
        app:layout_constraintStart_toStartOf="@+id/one"
        app:layout_constraintTop_toBottomOf="@+id/two"
        tools:text="Third text that dissapears, but should not go below the parent" />

</android.support.constraint.ConstraintLayout>

Rizwan Ahmed Shivalli 6 年前

你可以试试线性布局

编辑新代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="16dp"
android:paddingRight="16dp"
android:orientation="vertical">

<TextView
    android:id="@+id/one"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginStart="16dp"
    android:layout_marginEnd="16dp"
    android:maxLines="3"
    android:background="#ff0"
    android:text="One line lsfdjslkdf jksdljsdkljf sklksf klsjklsksjskfljsaklfj slkjfslkjfdskljfalskjflksdajfaklsjksadljfksfjksjkslfjsljsk lskjslksj ks flks jklsfjsl lsk slk"
    />

<TextView
    android:id="@+id/two"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginStart="16dp"
    android:layout_marginEnd="16dp"
    android:background="#0f0"
    android:text="Two kksldfj lskfd lksd jlkfsd jksld ksldfj sdlks dklfklsffsd klsdfjklsdf kdsflkj skldfsf sdfksdjf jsdfsjklfklskfls fklsf jklsdfjksf lksjdflk sdklsf lksfdjkls fk" />

<TextView
    android:id="@+id/three"
    android:layout_width="match_parent"        
    android:background="#f00"        
    android:layout_height="wrap_content"
    android:layout_marginStart="16dp"
    android:layout_marginEnd="16dp"
    android:text="Third text that dissapears, but should not go below the parent" />