ANDROID：ConstraintLayout：layout_constraintVertical_bias不按预期工作

Question

我正在尝试了解新的ConstraintLayout内容，作为iOS开发者，一切似乎还好。

这是我的视图

我想要做的是让4个正方形在垂直轴上稍微有些不同的大小（所以粉色60％，下面的蓝色40％，右边的蓝色40％，黑色60％）

通过阅读layout_constraintVertical_bias，这应该实现我的需求，但似乎没有任何变化。

<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">

    <android.support.constraint.Guideline
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/left_guideline"
        android:orientation="vertical"
        tools:layout_editor_absoluteY="0dp"
        tools:layout_editor_absoluteX="58dp"
        app:layout_constraintGuide_percent="0.16111112" />

    <android.support.constraint.Guideline
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/right_guideline"
        app:layout_constraintGuide_percent="0.85"
        android:orientation="vertical"
        tools:layout_editor_absoluteY="0dp"
        tools:layout_editor_absoluteX="306dp" />

    <android.support.constraint.Guideline
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/bottom_guideline"
        app:layout_constraintGuide_percent="0.85"
        android:orientation="horizontal"
        tools:layout_editor_absoluteY="434dp"
        tools:layout_editor_absoluteX="0dp" />

    <ImageButton
        android:id="@+id/yourStoryButton"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginBottom="8dp"
        android:layout_marginTop="8dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintLeft_toLeftOf="@+id/left_guideline"
        app:layout_constraintRight_toLeftOf="@+id/right_guideline"
        app:layout_constraintTop_toTopOf="@+id/bottom_guideline"
        app:layout_constraintVertical_bias="0.0" />

    <ImageButton
        style="?android:attr/borderlessButtonStyle"
        android:padding="0dp"
        android:id="@+id/leftTopButton"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toTopOf="@+id/leftBottomButton"
        app:layout_constraintLeft_toRightOf="@+id/left_main_guideline"
        app:layout_constraintRight_toLeftOf="@+id/rightTopButton"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.6"
        app:srcCompat="@color/colorAccent" />

    <ImageButton
        style="?android:attr/borderlessButtonStyle"
        android:padding="0dp"
        android:id="@+id/rightTopButton"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toTopOf="@+id/rightBottomButton"
        app:layout_constraintLeft_toRightOf="@+id/leftTopButton"
        app:layout_constraintRight_toLeftOf="@+id/right_main_guideline"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.4"
        app:srcCompat="@color/colorPrimary" />

    <ImageButton
        style="?android:attr/borderlessButtonStyle"
        android:padding="0dp"
        android:id="@+id/leftBottomButton"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toTopOf="@+id/bottom_guideline"
        app:layout_constraintTop_toBottomOf="@+id/leftTopButton"
        app:layout_constraintLeft_toRightOf="@+id/left_main_guideline"
        app:layout_constraintRight_toLeftOf="@+id/rightBottomButton"
        app:layout_constraintVertical_bias="0.4"
        app:srcCompat="@color/colorPrimaryDark" />

    <ImageButton
        android:id="@+id/rightBottomButton"
        style="?android:attr/borderlessButtonStyle"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:padding="0dp"
        app:layout_constraintBottom_toTopOf="@+id/bottom_guideline"
        app:layout_constraintLeft_toRightOf="@+id/leftBottomButton"
        app:layout_constraintRight_toLeftOf="@+id/right_main_guideline"
        app:layout_constraintTop_toBottomOf="@+id/rightTopButton"
        app:layout_constraintVertical_bias="0.6"

        app:srcCompat="@android:color/background_dark" />

    <android.support.constraint.Guideline
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/left_main_guideline"
        android:orientation="vertical"
        app:layout_constraintGuide_percent="0.0"
        tools:layout_editor_absoluteY="0dp"
        tools:layout_editor_absoluteX="0dp" />

    <android.support.constraint.Guideline
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/right_main_guideline"
        android:orientation="vertical"
        app:layout_constraintGuide_percent="1.0"
        tools:layout_editor_absoluteY="0dp"
        tools:layout_editor_absoluteX="360dp" />

</android.support.constraint.ConstraintLayout>

我是否理解正确，app:layout_constraintVertical_bias 控制视图的增长百分比（就像 weight）？

- Burf2000

Answer 1

不要设置 layout_constraintVertical_bias，而是要设置 layout_constraintVertical_weight

- schinj

---

那个完美地运作了（我正在写我的答案），你知道layout_constraintVertical_bias实际上是做什么的吗？ - Burf2000

如果父元素在某个轴向上的可用空间超过了视图的大小，则可以使用偏移量来排列视图。默认情况下，它们具有0.5的偏移量，意味着它们居中。如果想将它们对齐到特定方向，请使用偏移量。在这里可以更好地了解：https://developer.android.com/reference/android/support/constraint/ConstraintLayout.html 中的偏移量部分。 - schinj

Answer 2

为使其正常运作，您还应指定chainStyle。

app:layout_constraintVertical_chainStyle="packed"

- Maksym V.

Answer 3

所以，我仍然对layout_constraintVertical_bias的作用感到困惑，但app:layout_constraintVertical_weight却做到了我期望layout_constraintVertical_bias能做到的效果。

<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">

    <android.support.constraint.Guideline
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/left_guideline"
        android:orientation="vertical"
        tools:layout_editor_absoluteY="0dp"
        tools:layout_editor_absoluteX="58dp"
        app:layout_constraintGuide_percent="0.16111112" />

    <android.support.constraint.Guideline
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/right_guideline"
        app:layout_constraintGuide_percent="0.85"
        android:orientation="vertical"
        tools:layout_editor_absoluteY="0dp"
        tools:layout_editor_absoluteX="306dp" />

    <android.support.constraint.Guideline
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/bottom_guideline"
        app:layout_constraintGuide_percent="0.85"
        android:orientation="horizontal"
        tools:layout_editor_absoluteY="434dp"
        tools:layout_editor_absoluteX="0dp" />

    <ImageButton
        android:id="@+id/yourStoryButton"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginBottom="8dp"
        android:layout_marginTop="8dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintLeft_toLeftOf="@+id/left_guideline"
        app:layout_constraintRight_toLeftOf="@+id/right_guideline"
        app:layout_constraintTop_toTopOf="@+id/bottom_guideline"
        app:layout_constraintVertical_bias="0.0" />

    <ImageButton
        style="?android:attr/borderlessButtonStyle"
        android:padding="0dp"
        android:id="@+id/leftTopButton"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toTopOf="@+id/leftBottomButton"
        app:layout_constraintLeft_toRightOf="@+id/left_main_guideline"
        app:layout_constraintRight_toLeftOf="@+id/rightTopButton"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_weight="0.6"
        app:srcCompat="@color/colorAccent" />

    <ImageButton
        android:id="@+id/rightTopButton"
        style="?android:attr/borderlessButtonStyle"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:padding="0dp"
        app:layout_constraintBottom_toTopOf="@+id/rightBottomButton"
        app:layout_constraintLeft_toRightOf="@+id/leftTopButton"
        app:layout_constraintRight_toLeftOf="@+id/right_main_guideline"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_weight="0.4"
        app:srcCompat="@android:color/holo_orange_dark" />

    <ImageButton
        style="?android:attr/borderlessButtonStyle"
        android:padding="0dp"
        android:id="@+id/leftBottomButton"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toTopOf="@+id/bottom_guideline"
        app:layout_constraintTop_toBottomOf="@+id/leftTopButton"
        app:layout_constraintLeft_toRightOf="@+id/left_main_guideline"
        app:layout_constraintRight_toLeftOf="@+id/rightBottomButton"
        app:layout_constraintVertical_weight="0.4"
        app:srcCompat="@color/colorPrimaryDark" />

    <ImageButton
        android:id="@+id/rightBottomButton"
        style="?android:attr/borderlessButtonStyle"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:padding="0dp"
        app:layout_constraintBottom_toTopOf="@+id/bottom_guideline"
        app:layout_constraintLeft_toRightOf="@+id/leftBottomButton"
        app:layout_constraintRight_toLeftOf="@+id/right_main_guideline"
        app:layout_constraintTop_toBottomOf="@+id/rightTopButton"
        app:layout_constraintVertical_weight="0.6"
        app:srcCompat="@android:color/background_dark" />

    <android.support.constraint.Guideline
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/left_main_guideline"
        android:orientation="vertical"
        app:layout_constraintGuide_percent="0.0"
        tools:layout_editor_absoluteY="0dp"
        tools:layout_editor_absoluteX="0dp" />

    <android.support.constraint.Guideline
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/right_main_guideline"
        android:orientation="vertical"
        app:layout_constraintGuide_percent="1.0"
        tools:layout_editor_absoluteY="0dp"
        tools:layout_editor_absoluteX="360dp" />

</android.support.constraint.ConstraintLayout>

- Burf2000

---

哦，很高兴你找到了它。 - schinj