ConstraintLayout内TextView的动态点答案

【问题标题】：Dynamic spot of TextView within ConstraintLayoutConstraintLayout内TextView的动态点
【发布时间】：2020-10-11 20:39:06
【问题描述】：

是否有可能以某种方式沿ConstraintLayout 中的水平线动态定义 TextView 的点？我有水平线，我有一些整数值（它可以从 0 到 40），如果它会更低，它应该位于更靠近这条水平线的左端，如果值会更高，则 textview应该更靠近这条水平线的右端。

现在我的 xml 布局如下所示：

<?xml version="1.0" encoding="utf-8"?>
<layout 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">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/white">

    ...

        <TextView
            android:id="@+id/lowestScoreTextView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="@dimen/spacing_3xl"
            android:layout_marginStart="@dimen/spacing_xl"
        android:text="0"
            ...
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintEnd_toStartOf="@id/firstLine"
            app:layout_constraintTop_toBottomOf="@id/titleTextView"
            app:layout_constraintHorizontal_chainStyle="packed" />

        <View
            android:id="@+id/firstLine"
            android:layout_width="50dp"
            android:layout_height="@dimen/spacing_2xs"
        ...
            android:layout_marginStart="@dimen/spacing_2xs"
            android:layout_marginEnd="@dimen/spacing_xs"
            app:layout_constraintStart_toEndOf="@id/lowestScoreTextView"
            app:layout_constraintEnd_toStartOf="@id/secondLine"
            app:layout_constraintTop_toTopOf="@id/lowestScoreTextView"
            app:layout_constraintBottom_toBottomOf="@id/lowestScoreTextView"
            app:layout_constraintHorizontal_chainStyle="packed" />

        <View
            android:id="@+id/secondLine"
            android:layout_width="100dp"
            android:layout_height="@dimen/spacing_2xs"
            ...
            android:layout_marginEnd="@dimen/spacing_xs"
            app:layout_constraintStart_toEndOf="@id/firstLine"
            app:layout_constraintEnd_toStartOf="@id/thirdLine"
            app:layout_constraintTop_toTopOf="@id/lowestScoreTextView"
            app:layout_constraintBottom_toBottomOf="@id/lowestScoreTextView"
            app:layout_constraintHorizontal_chainStyle="packed" />

        <View
            android:id="@+id/thirdLine"
            android:layout_width="50dp"
            android:layout_height="@dimen/spacing_2xs"
            ...
            android:layout_marginEnd="@dimen/spacing_2xs"
            app:layout_constraintStart_toEndOf="@id/secondLine"
            app:layout_constraintEnd_toStartOf="@id/highestScoreTextView"
            app:layout_constraintTop_toTopOf="@id/lowestScoreTextView"
            app:layout_constraintBottom_toBottomOf="@id/lowestScoreTextView"
            app:layout_constraintHorizontal_chainStyle="packed" />

        <TextView
            android:id="@+id/highestScoreTextView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginEnd="@dimen/spacing_xl"
            android:text="40"
            ...
            app:layout_constraintStart_toEndOf="@id/thirdLine"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintTop_toTopOf="@id/lowestScoreTextView"
            app:layout_constraintBottom_toBottomOf="@id/lowestScoreTextView"
            app:layout_constraintHorizontal_chainStyle="packed" />

    ...

    </androidx.constraintlayout.widget.ConstraintLayout>
</layout>

【问题讨论】：

标签： android android-layout textview

【解决方案1】：

使用ConstraintSet 以编程方式为您的TextView 提供水平Bias：

ConstraintSet setWithBias = new ConstraintSet();
setWithBias.clone(constraintLayout); // You'd require a reference to this ConstraintLayout through findViewById()
setWithBias.setHorizontalBias(R.id.OfYourTextView, 0.2); // 20% horizontal bias (0 - extreme left, 1 - extreme right)
setWithBias.applyTo(constraintLayout); // Apply changes to your ConstraintLayout

请注意，您的TextView 的左右边缘必须连接到适当的极端，这样才能正常工作。 根据您的代码：firstLine 的左边缘和thirdLine 的右边缘。

如果你不设置偏差，它会在上面的约束下停留在中间，这隐含地表明bias 是 0.5

【讨论】：