在ConstraintLayout中使用minHeight查看 [英] View with minHeight in ConstraintLayout
问题描述
我在NestedScrollView中有一个ConstraintLayout. ConstraintLayout包含一堆视图，但最后一个View可以具有动态高度来填充底部空间(如果有的话)，但如果没有足够的空间，则还必须具有最小高度.
为了论证，这里是一个例子.
<android.support.v4.widget.NestedScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true">
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
tools:layout_height="match_parent">
<View
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintHeight_min="1500dp"
android:background="@color/red"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintTop_toTopOf="parent"/>
</android.support.constraint.ConstraintLayout>
</android.support.v4.widget.NestedScrollView>
如您所见，我已经放入了ConstraintLayout版本，但是它不起作用.显然，这些值非常大，但这仅用于测试.
如果我未在NestedScrollView上设置fillViewport="true"，则ConstraintLayout的高度为0.当我设置fillViewport时，ConstraintLayout不会滚动，而只会填满屏幕./p>
如何设置视图以使其扩展到ConstraintLayout的底部，该底部应与视口一样大，但是如果我的视图不在minHeight的范围内，那么我们允许滚动吗?
我正在使用ConstraintLayout库的版本1.0.2.
我希望看到的是一直到父级底部，但是如果该尺寸小于1500dp，则视图会滚动.
我已经像android:layout_height="1500dp"这样输入了1500dp，并且视图相应地滚动.
更新1
好像是我将布局放在FragmentViewPager中之后. app:layout_constraintHeight_min属性不受尊重，它仅与视口的高度匹配.
我还尝试将NestedScrollView从片段中取出，并将ViewPager放入片段中，但是再次无效.
将此属性添加到您要拉伸的视图中:
app:layout_constraintHeight_default="spread"
我制作了一个小应用程序来演示.没有Java逻辑可言，但这是布局:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.NestedScrollView
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"
android:fillViewport="true">
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="16dp"
android:background="#caf">
<TextView
android:id="@+id/one"
android:layout_width="0dp"
android:layout_height="48dp"
android:gravity="center"
android:text="hello world"
android:background="#fff"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintBottom_toTopOf="@+id/two"/>
<TextView
android:id="@+id/two"
android:layout_width="0dp"
android:layout_height="48dp"
android:gravity="center"
android:text="hello world"
android:background="#eee"
app:layout_constraintTop_toBottomOf="@+id/one"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintBottom_toTopOf="@+id/three"/>
<TextView
android:id="@+id/three"
android:layout_width="0dp"
android:layout_height="0dp"
android:gravity="center"
android:text="hello world"
android:background="#ddd"
app:layout_constraintHeight_default="spread"
app:layout_constraintHeight_min="300dp"
app:layout_constraintTop_toBottomOf="@+id/two"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintBottom_toBottomOf="parent"/>
</android.support.constraint.ConstraintLayout>
</android.support.v4.widget.NestedScrollView>
当底视图小于剩余可用空间时，底视图会拉伸以填充视口，并且无法滚动:
当底视图大于剩余可用空间时，底视图将保持固定高度，这使滚动成为可能:
I have a ConstraintLayout inside a NestedScrollView. The ConstraintLayout contains a bunch of views but the last View can have a dynamic height to fill up the bottom space iff there is any but it also needs to be a minimum height if there is not enough space.
For arguments sake, here is an example.
<android.support.v4.widget.NestedScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true">
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
tools:layout_height="match_parent">
<View
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintHeight_min="1500dp"
android:background="@color/red"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintTop_toTopOf="parent"/>
</android.support.constraint.ConstraintLayout>
</android.support.v4.widget.NestedScrollView>
As you can see I have put the ConstraintLayout version in but it doesn't work. Obviously the values are ridiculously large but this is just for testing.
If I don't set fillViewport="true" on the NestedScrollView then ConstraintLayout has a height of 0. When I do set the fillViewport, the ConstraintLayout does not scroll but just fills the screen.
How can I set the View so that it expands to the bottom of the ConstraintLayout which should be as big as the Viewport but if my View is not of the minHeight then we allow scrolling?
I am using version 1.0.2 of the ConstraintLayout library.
What I expect to see is the being all the way to the bottom of the parent but if that size is less than 1500dp then the view scrolls.
I have entered 1500dp like so android:layout_height="1500dp" and the view scrolls accordingly.
UPDATE 1
Seems to be once I put the layout within a FragmentViewPager. The app:layout_constraintHeight_min property isn't respected and it only matches the height of the viewport.
I also tried taking the NestedScrollView out of the fragment and putting the ViewPager inside it but again didn't work.
Add this attribute to the view you'd like to have stretch:
app:layout_constraintHeight_default="spread"
I made a tiny app to demonstrate. No java logic to speak of, but here's the layout:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.NestedScrollView
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"
android:fillViewport="true">
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="16dp"
android:background="#caf">
<TextView
android:id="@+id/one"
android:layout_width="0dp"
android:layout_height="48dp"
android:gravity="center"
android:text="hello world"
android:background="#fff"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintBottom_toTopOf="@+id/two"/>
<TextView
android:id="@+id/two"
android:layout_width="0dp"
android:layout_height="48dp"
android:gravity="center"
android:text="hello world"
android:background="#eee"
app:layout_constraintTop_toBottomOf="@+id/one"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintBottom_toTopOf="@+id/three"/>
<TextView
android:id="@+id/three"
android:layout_width="0dp"
android:layout_height="0dp"
android:gravity="center"
android:text="hello world"
android:background="#ddd"
app:layout_constraintHeight_default="spread"
app:layout_constraintHeight_min="300dp"
app:layout_constraintTop_toBottomOf="@+id/two"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintBottom_toBottomOf="parent"/>
</android.support.constraint.ConstraintLayout>
</android.support.v4.widget.NestedScrollView>
The bottom view stretches to fill the viewport when it is smaller than the remaining available space, and scrolling is impossible:
The bottom view maintains a fixed height when it is larger than the remaining available space, which makes scrolling possible:
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