ConstraintLayout边距不起作用

Question

marginTop如果我所约束的视图可见性消失,则使用下面的xml 会被忽略.

目前最新的布局lib版本会发生这种情况 com.android.support.constraint:constraint-layout:1.0.0-beta4

例:

tvMessage和ivCommentImage是visible-在16DP上边距llLeftActions和llRightActions工作正常.如果ivCommentImage是gone边距被忽略.

<android.support.v7.widget.CardView
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

<android.support.constraint.ConstraintLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="16dp">

<!-- some more views here -->

    <TextView
        android:id="@+id/tvMessage"
        style="@style/SocialFeed.Description"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginEnd="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginRight="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/ivProfile"
        app:layout_goneMarginTop="0dp"
        tools:text="@string/lorem_ipsum_140chars"/>

    <android.support.v7.widget.AppCompatImageView
        android:id="@+id/ivCommentImage"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:adjustViewBounds="true"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/tvMessage"
        app:layout_goneMarginTop="0dp"
        />

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

    <LinearLayout
        android:id="@+id/llLeftActions"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:gravity="center_vertical|left"
        android:orientation="horizontal"
        app:layout_constraintLeft_toLeftOf="@+id/tvMessage"
        app:layout_constraintRight_toLeftOf="@+id/gCenter"
        app:layout_constraintTop_toBottomOf="@+id/ivCommentImage"
        app:layout_goneMarginTop="0dp"
        />

    <LinearLayout
        android:id="@+id/llRightActions"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:gravity="center_vertical|right"
        android:orientation="horizontal"
        app:layout_constraintLeft_toLeftOf="@+id/gCenter"
        app:layout_constraintRight_toRightOf="@+id/tvMessage"
        app:layout_constraintTop_toBottomOf="@+id/ivCommentImage"
        app:layout_goneMarginTop="0dp"/>


</android.support.constraint.ConstraintLayout>

</android.support.v7.widget.CardView>

Answer 1

它的工作完全按预期-请注意,您添加layout_goneMarginTop="0dp"的@id/llLeftActions和@id/llRightActions...

这意味着当他们指向(@id/ivCommentImage)的小部件被标记为已消失时,将用于顶部连接的边距将是... 0dp,而不是16dp的边距.这就是这些属性的用途!:)

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