无法在约束组上设置可见性 [英] Can't set visibility on constraint group

问题描述

当我尝试在按钮单击上设置组的可见性时，它不会影响视图的可见性.使用com.android.support.constraint:constraint-layout:1.1.0-beta4.我尝试过将其设置为逐元素，但没有任何问题，但是该小组没有成功.

When i try to set the visibility of the group on button click,it doesn't affect the view's visibility.Using com.android.support.constraint:constraint-layout:1.1.0-beta4. I've tried setting it element-wise without problems,but no success with the group.

我的MainActivity.kt

private fun toggleLoginUI(show: Boolean) {
    if (show) {
        group.visibility = VISIBLE
    } else {
        group.visibility = INVISIBLE
    }
}

fun onClick(view: View) {
    when (view.id) {
        R.id.button -> toggleLoginUI(true)
        R.id.button4 -> toggleLoginUI(false)
    }
}

我的activity_main.xml

    <android.support.constraint.ConstraintLayout..

            <TextView
                android:id="@+id/textView"
... />

            <TextView
                android:id="@+id/textView2"
... />

            <Button
                android:id="@+id/button"
.../>

            <Button
                android:id="@+id/button4"
... />


            <android.support.constraint.Group
                android:id="@+id/group"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:visibility="visible"
                app:constraint_referenced_ids="textView,textView2" />
            </android.support.constraint.ConstraintLayout>

推荐答案

对我来说，这似乎是个错误. GONE可以，但是INVISIBLE不能，我认为应该.除非有人可以发表我的想法错误的地方，否则可能值得提交错误报告. (我正在使用constraint-layout:1.1.0-beta4.)

This looks like a bug to me. GONE works but INVISIBLE doesn't and I think it should. It may be worth a bug report unless someone can post where my thinking is wrong. (I am using constraint-layout:1.1.0-beta4.)

同时，这是一种变通方法，可显式检索组中的ID并设置每个检索到的视图的可见性.

In the meantime, here is a work-around that explicitly retrieves the ids within the group and sets the visibility of each retrieved view.

在MainActivity.kt中

private fun toggleLoginUI(show: Boolean) {
    if (show) {
        setGroupVisibility(mLayout, group, Group.VISIBLE)
    } else {
        setGroupVisibility(mLayout, group, Group.INVISIBLE)
    }
}

private fun setGroupVisibility(layout: ConstraintLayout, group: Group, visibility: Int) {
    val refIds = group.referencedIds
    for (id in refIds) {
        layout.findViewById<View>(id).visibility = visibility
    }
}

mLayout是ConstraintLayout.

更新:这是另一种变通办法，它利用更改为GONE或从其更改为预期的效果这一事实:

Update: Here is another work-around that takes advantage of the fact that changing to/from GONE works as expected:

private fun toggleLoginUI(show: Boolean) {
    if (show) {
        group.visibility = GONE
        group.visibility = VISIBLE
    } else {
        group.visibility = GONE
        group.visibility = INVISIBLE
    }
}

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