ExpandableListView 可扩展列表在其高度为 wrap_content 且下方有内容时不扩展

问题描述 投票：0回答：7

这是我的布局代码。当我单击可展开列表视图时，它不会展开。但是，如果我增加列表的高度，它会扩展。有没有办法通过代码动态增加列表的高度？我可以让它在我的布局中间展开吗？因为如果我增加高度，它只会在折叠列表中添加不必要的空白。

代码：

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:paddingBottom="@dimen/activity_vertical_margin"
        android:paddingLeft="@dimen/activity_horizontal_margin"
        android:paddingRight="@dimen/activity_horizontal_margin"
        android:paddingTop="@dimen/activity_vertical_margin"
        tools:context="com.pocketcash.pocketcash.HomeActivity">

        <Switch
            android:id="@+id/detailedCashInfoSwitch"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentEnd="true"
            android:layout_alignParentRight="true"
            android:layout_alignParentTop="true"
            android:onClick="cashToggleSwitchClicked"
            android:text="Toggle Detailed Cash Info" />

        <Button
            android:id="@+id/addCashButton"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/expandableListView2"
            android:layout_centerHorizontal="true"
            android:onClick="launchAddCash"
            android:text="Add cash" />

        <Button
            android:id="@+id/addExpenditureButton"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/addCashButton"
            android:layout_centerHorizontal="true"
            android:layout_marginTop="25dp"
            android:onClick="launchAddExpenditure"
            android:text="Add expenditure" />

        <TextView
            android:id="@+id/recentLogsText"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"
            android:layout_below="@+id/addExpenditureButton"
            android:layout_marginTop="50dp"
            android:text="Recent Logs:"
            android:textAppearance="?android:attr/textAppearanceMedium" />

        <TextView
            android:id="@+id/logText"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"
            android:layout_below="@+id/recentLogsText"
            android:layout_marginTop="0dp"
            android:text="Small Text"
            android:textAppearance="?android:attr/textAppearanceSmall" />

        <TextView
            android:id="@+id/recentViewAllText"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignTop="@+id/recentLogsText"
            android:layout_marginLeft="10dp"
            android:layout_toEndOf="@+id/recentLogsText"
            android:layout_toRightOf="@+id/recentLogsText"
            android:onClick="recentViewLogClicked"
            android:text="(view all)"
            android:textAppearance="?android:attr/textAppearanceMedium" />

        <TextView
            android:id="@+id/addViewAllText"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/addCashButton"
            android:layout_centerHorizontal="true"
            android:onClick="addViewLogClicked"
            android:text="(view logs)"
            android:textAppearance="?android:attr/textAppearanceSmall" />

        <TextView
            android:id="@+id/expenseViewAllText"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/addExpenditureButton"
            android:layout_centerHorizontal="true"
            android:onClick="expenseViewLogClicked"
            android:text="(view logs)"
            android:textAppearance="?android:attr/textAppearanceSmall" />

        <ImageView
            android:id="@+id/userImage"
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"
            android:layout_below="@+id/detailedCashInfoSwitch"
            android:layout_marginTop="34dp"
            android:background="@drawable/default_user" />

        <TextView
            android:id="@+id/nameText"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignTop="@+id/userImage"
            android:layout_marginLeft="25dp"
            android:layout_toEndOf="@+id/userImage"
            android:layout_toRightOf="@+id/userImage"
            android:text="Name"
            android:textAppearance="?android:attr/textAppearanceLarge" />

        <TextView
            android:id="@+id/logoutText"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignLeft="@+id/nameText"
            android:layout_alignStart="@+id/nameText"
            android:layout_below="@+id/nameText"
            android:clickable="true"
            android:onClick="logUserOut"
            android:text="logout"
            android:textAppearance="?android:attr/textAppearanceSmall" />

        <ImageButton
            android:id="@+id/settingsButton"
            android:layout_width="25dp"
            android:layout_height="25dp"
            android:layout_alignTop="@+id/nameText"
            android:layout_marginLeft="25dp"
            android:layout_toEndOf="@+id/nameText"
            android:layout_toRightOf="@+id/nameText"
            android:background="@drawable/settingsicon"
            android:onClick="launchSettingsActivity" />

        <fragment
            android:id="@+id/fragment_currentBalanceInfo"
            android:name="com.pocketcash.pocketcash.CurrentBalanceInfoFragment"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/userImage"
            android:layout_centerHorizontal="true"
            tools:layout="@layout/fragment_current_balance_info" />

        <ExpandableListView
            android:id="@+id/expandableListView2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/fragment_currentBalanceInfo"
            android:layout_centerHorizontal="true"
            android:clickable="true" />

    </RelativeLayout>
</ScrollView>
android xml android-studio expandablelistview android-wrap-content
7个回答
5
投票

经过对这个主题的大量研究，我只能得出结论，像可扩展列表视图这样的可滚动对象不能在另一个可滚动视图中声明。 但是，为了在运行时解决这个问题，我对我的 Java 代码进行了一些调整。

    expListView.setOnGroupExpandListener(new ExpandableListView.OnGroupExpandListener() {
        @Override
        public void onGroupExpand(int groupPosition) {
            int height = 0;
            for (int i = 0; i < expListView.getChildCount(); i++) {
                height += expListView.getChildAt(i).getMeasuredHeight();
                height += expListView.getDividerHeight();
            }
            expListView.getLayoutParams().height = (height+6)*10;
        }
    });

    // Listview Group collapsed listener
    expListView.setOnGroupCollapseListener(new ExpandableListView.OnGroupCollapseListener() {

        @Override
        public void onGroupCollapse(int groupPosition) {
            expListView.getLayoutParams().height = 61;
        }
    });

这样我可以在展开或折叠时动态调整小部件的高度。它不是一个可靠的方法，它适用于点击和试用，所以我最终不得不将这个小部件移动到一个全新的活动中。然而，这确实完美无缺。但如果有人找到更好的答案，请分享。

3
投票

正如 Romain Guy（谷歌工程师致力于 UI 工具包）在他的帖子中所说

通过将宽度设置为

wrap_content
，您告诉 ListView 与其最宽的子项一样宽。因此，ListView 必须测量其项目并获取必须在适配器上调用 
getView()
的项目。这可能会发生多次，具体取决于布局遍数、父布局的行为等。

因此，如果您将 

ListView
的布局宽度或布局高度设置为 
wrap_content
ListView
将尝试测量附加到它的每个视图 - 这绝对不是您想要的。

记住：避免始终为

ListViews
或
GridViews
或
ExpandableListView
设置wrap_content，有关更多详细信息，请参阅此Google I/O视频谈论列表视图的世界

所以让

ExpandableListView
到
match_parent

1
投票

我知道这个问题已经得到回答，但我有另一个解决方案可以适用于更多情况：我通过计算项目数量来设置列表视图的初始高度，然后通过检索子项在折叠/展开组时更新此高度展开/折叠组的计数。这是一个示例代码：

int item_size = 50;  // 50px
int sub_item_size = 40;  // 40px
expListView.getLayoutParams().height = item_size*myAdapter.getGroupCount();
expenseListView.setAdapter(myAdapter);
// ListView Group Expand Listener
expenseListView.setOnGroupExpandListener(new ExpandableListView.OnGroupExpandListener() {
    @Override
    public void onGroupExpand(int groupPosition) {
        int nb_children = myAdapter.getChildrenCount(groupPosition);
        expenseListView.getLayoutParams().height += sub_item_size*nb_children;
    }
});

// Listview Group collapsed listener
expenseListView.setOnGroupCollapseListener(new ExpandableListView.OnGroupCollapseListener() {
    @Override
    public void onGroupCollapse(int groupPosition) {
        int nb_children = myAdapter.getChildrenCount(groupPosition);
        expenseListView.getLayoutParams().height -= sub_item_size*nb_children;
    }
});
1
投票

通常我们不能在Scrollview 中使用ListView、GridView 或ExpandableListView。如果您需要它，那么您必须为可扩展的 ListView 提供固定的高度。

private void setListViewHeight(final ExpandableListView listView, final int groupPosition) {
    final ExpandableListAdapter listAdapter = (ExpandableListAdapter) listView.getExpandableListAdapter();
    int totalHeight = 0;
    // be careful with unspecified width measure spec, it will ignore all layout params and even
    // screen dimensions, so to get correct height, first get maximum width View can use and
    // call measure() this way
    final int desiredWidth = View.MeasureSpec.makeMeasureSpec(listView.getWidth(), View.MeasureSpec.EXACTLY);
    for (int i = 0; i < listAdapter.getGroupCount(); i++) {
        final View groupItem = listAdapter.getGroupView(i, false, null, listView);
        groupItem.measure(desiredWidth, View.MeasureSpec.UNSPECIFIED);

        totalHeight += groupItem.getMeasuredHeight();
        // count only expanded other groups or the clicked collapsed one
        if (((listView.isGroupExpanded(i)) && (i != groupPosition))
                || ((!listView.isGroupExpanded(i)) && (i == groupPosition))) {
            for (int j = 0, childrenNumber = listAdapter.getChildrenCount(i); j < childrenNumber; j++) {

                final View listItem = listAdapter.getChildView(i, j, j == childrenNumber - 1, null, listView);
                listItem.measure(desiredWidth, View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED));
                totalHeight += listItem.getMeasuredHeight();
            }
        }
    }
    final ViewGroup.LayoutParams params = listView.getLayoutParams();
    final int height = totalHeight
            + (listView.getDividerHeight() * (listAdapter.getGroupCount() - 1));
    params.height = height;
    listView.setLayoutParams(params);
    listView.requestLayout();
}

并将此方法分配给列表组单击：

expandableListView.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {
    @Override
    public boolean onGroupClick(final ExpandableListView expandableListView, final View view, final int groupPosition, final long id) {
        setListViewHeight(expandableListView, groupPosition);
        return false;
    }
});

重要：虽然这段代码在大多数情况下应该有效，但是当子列表项是带有

android:layout_height="wrap_content"
的TextViews时我遇到了一些问题，因此它们的高度取决于它们的宽度，这可能与这个问题有关：ViewGroup{TextView, ...}.getMeasuredHeight 给出的错误值小于实际高度。如果您设法修复它，请发表评论。

0
投票

不幸的是，似乎没有办法使用

wrap_content
作为
ExpandableListView
的高度。相反，设置固定高度和
android:nestedScrollingEnabled="true"
对我有用。

0
投票

我找到了一种更好的解决方案，可以使用以下不太复杂但效率更高的 Kotlin 代码来实现这种现象。

在所有人记住一些要点之前：

  1. 使用固定
    height
    父子视图。
  2. 将父母和孩子的身高提取到
    dimens.xml
    文件中。
  3. 在ExpandableListView中设置
    divider='@null'
    、
    scrollbars="none"
    、
    groupIndicator="@null"
    （对于customGroupIndicator，否则忽略）。
  4. 切勿使用 
    paddingVertical
    ，包括 
    paddingTop
    和 
    paddingBottom
    ，对于具有动态高度的视图，将它们替换为 
    layoutMargins
    。

代码逻辑（对我来说，这个块是名为

initUi(uiObject)
的ViewModel函数的一部分）

//Here `ui` is a DataBinding object.
//You can use ViewBinding or simple Android findViewById as per your comfort.

val data: List<ModelClass> = listObject
val context = ui.root.context

ui.expandableList.apply {
    val mAdapter = MyExpandableListAdapter(data, context)
    setAdapter(mAdapter)

    //fetching parent height from dimens.xml
    val parentViewHeight = ceil(
        context.resources.getDimension(R.dimen.layout_menu_parent_height)
    ).toInt()

    //fetching child height from dimens.xml
    val childViewHeight = ceil(
        context.resources.getDimension(R.dimen.layout_menu_child_height)
    ).toInt()

    //Setting up the initial height of view when All parents are collapsed
    layoutParams.height = data.size * parentViewHeight

    setOnGroupExpandListener { groupPosition ->
        //Increasing the height for Expanded SubCategory
        layoutParams.height += mAdapter.getChildrenCount(groupPosition) * childViewHeight
    }

    setOnGroupCollapseListener { groupPosition ->
        //Decreasing the height for Collapsed SubCategory
        layoutParams.height -= mAdapter.getChildrenCount(groupPosition) * childViewHeight
    }
}

MyExpandableListAdapter.kt

class FragmentMenuExpandableListAdapter(
    val data: List<Data>, val context: Context
): BaseExpandableListAdapter() {
    //Declaring inflater Once can save a lot of CPU and RAM uses... 
    private val inflater = LayoutInflater.from(context)

    override fun getGroupCount(): Int = data.size

    override fun getChildrenCount(groupPosition: Int): Int = data[groupPosition].subcategories.size

    override fun getGroup(groupPosition: Int): Data = data[groupPosition]

    override fun getChild(groupPosition: Int, childPosition: Int) = data[groupPosition].subcategories[childPosition]

    override fun getGroupId(groupPosition: Int): Long = groupPosition.toLong()

    override fun getChildId(groupPosition: Int, childPosition: Int): Long = "$groupPosition$childPosition0".toLong()

    override fun hasStableIds(): Boolean = true

    override fun getGroupView(
        groupPosition: Int,
        isExpanded: Boolean,
        convertView: View?,
        parent: ViewGroup
    ): View {
        val binding = LayoutMenuParentBinding.inflate(inflater, parent, false)
        binding.apply {
            val temp = getGroup(groupPosition)
            title.text = temp.category_name

            //here I used a custom ImageView as GroupIndicator
            //So following code chunk is Optional
            if(temp.subcategories.isEmpty()) dropdownIcon.visibility = View.GONE
            else dropdownIcon.let { icon ->
                val view = parent as ExpandableListView
                icon.setImageResource(
                    if(view.isGroupExpanded(groupPosition)) {
                        icon.setOnClickListener { view.collapseGroup(groupPosition) }
                        R.drawable.ic_state_expanded
                    }
                    else {
                        icon.setOnClickListener {
                            view.expandGroup(groupPosition)
                        }
                        R.drawable.ic_state_collapsed
                    }
                )
            }

            root.setOnClickListener {
                TODO("Do on Parent click")
            }
        }
        return binding.root
    }

    override fun getChildView(
        groupPosition: Int,
        childPosition: Int,
        isLastChild: Boolean,
        convertView: View?,
        parent: ViewGroup?
    ): View {
        val binding = LayoutMenuChildBinding.inflate(
            inflater, parent, false
        ).apply {
            val temp = getChild(groupPosition, childPosition)
            title.text = temp.categoryName

            root.setOnClickListener {
                TODO("Do on Child click")
            }
        }
        return binding.root
    }

    override fun isChildSelectable(groupPosition: Int, childPosition: Int): Boolean = true
}
0
投票

在我的例子中，wrap_content 和 match_parent 没有工作。我得到了适用于所有屏幕分辨率的解决方案。尝试如下添加自定义可扩展列表视图，并在您的 XML 文件中使用该视图。

public class CustomExpandableListview extends ExpandableListView { 
   
     public CustomExpandableListview(Context context, AttributeSet attrs) { 
            super(context, attrs);        
 }       

@Override public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { 
         int heightMeasureSpec_custom = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2, MeasureSpec.AT_MOST);       
    super.onMeasure(widthMeasureSpec, heightMeasureSpec_custom);             
    ViewGroup.LayoutParams params = getLayoutParams();            
    params.height = getMeasuredHeight();         
   } 
}

<com.ui.CustomExpandableListview     
android:id="@+id/device_break_down_list"     
android:layout_width="match_parent"     
android:layout_height="wrap_content"     
android:groupIndicator="@null" />
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