ConstraintLayout在TextView中对齐文本

Question

How to align text in TextView when it is inside ConstraintLayout? I cannot use layout_width="match_parent . Tried this, does not work :(

android:gravity="start"
android:textAlignment="gravity"

Answer 1

1. Make the TextView match parent with:

    android:layout_width="0dp" 

2. Then define the textAlignment property:

    android:textAlignment="viewEnd" 

Example, align right in a left to right language:

    <TextView
     android:id="@+id/tv_item"
     style="@style/text_highlight_small_title"
     android:layout_width="0dp"
     android:layout_height="wrap_content"
     android:text="@string/my_text"
     android:textAlignment="viewStart"
     app:layout_constraintBottom_toBottomOf="parent"
     app:layout_constraintEnd_toEndOf="parent"
     app:layout_constraintStart_toStartOf="parent"
     app:layout_constraintTop_toTopOf="parent"
     tools:text="Sample Text" />

Note you can use different values for textAlignment as defined in the documentation .

Answer 2

use this xml code

<?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"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:text="TextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/textView"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:layout_marginLeft="16dp"
        android:layout_marginEnd="16dp"
        app:layout_constraintRight_toRightOf="parent"
        android:layout_marginRight="16dp" />
</android.support.constraint.ConstraintLayout>

Answer 3

Try this:

<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:context="com.example.YOURUSER.YOURPROJECT.YOURACTIVITY">

    <TextView
        android:id="@+id/TextView1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

Answer 4

Try this:

<TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/textView"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        android:gravity="right"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:layout_marginLeft="16dp"
        android:layout_marginEnd="16dp"
        app:layout_constraintRight_toRightOf="parent"
        android:layout_marginRight="16dp" />

Answer 5

Solution:

use this xml code

<?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"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:text="TextView"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:id="@+id/textView"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:layout_marginLeft="16dp"
        android:layout_marginEnd="16dp"
        android:gravity="start"
        app:layout_constraintRight_toRightOf="parent"
        android:layout_marginRight="16dp" />
</android.support.constraint.ConstraintLayout>

Hope it helps.

Answer 6

In general, if you have more then one TextView in a single line it is not trivial to align the first TextView to the left. I have used a Guideline for this pourpose and it works perfectly. If you remove the GuideLine it doesn't works. Here is the xml:

<TextView
    android:id="@+id/textView1"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_marginTop="130dp"
    android:ellipsize="end"
    android:maxLines="1"
    android:text="first very long very long long long long long very long text"
    android:textAlignment="viewStart"
    app:layout_constraintEnd_toStartOf="@id/textView2"
    app:layout_constraintStart_toStartOf="@+id/guideline"
    app:layout_constraintTop_toTopOf="parent" />

<TextView
    android:id="@+id/textView2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginTop="130dp"
    android:text="second text"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

<android.support.constraint.Guideline
    android:id="@+id/guideline"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    app:layout_constraintGuide_begin="0dp" />

Answer 7

Unfortunately, we are missing the whole XML of your layout, but let's assume you have something like this:

<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Something Important to align"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

Now if you create exactly this layout, TextView is gonna be in the center. This is the default behavior of the ConstraintLayout, it always tries to center views in it if you set constraints this way. This behavior can be influenced by app:layout_constraintHorizontal_bias and app:layout_constraintVertical_bias property of the TextView. Default values for both are 0.5 what you can translate to 50%. If you set them both to 0, you will find the TextView in the top left position . If you set them both to 1, the TextView will end up in the bottom right position . You got the idea, this way you can position your TextView or any View wherever you want.

The bias properties are also described in the official documentation here .

Fully working example of TextView aligned to center vertically and aligned to right horizontally:

<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Something Important to align"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="1"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.5" />

</android.support.constraint.ConstraintLayout>

Answer 8

使用设计，因为它比xml 视频文件容易得多