ExpandableListView ——无子组的隐藏指示符

在 ExpandableListView中，是否有方法隐藏没有子组的组指示符？

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android:groupIndicator属性采用一个启用状态的可绘制属性。也就是说，您可以为不同的状态设置不同的图像。

当组没有子级时，对应的状态是“ state _ void”

查看以下参考链接:

这个和这个 href = “ http://developer.android.com/reference/android/R.attr.html # state _ void”rel = “ norefrer”> this

For state_empty, you can set a different image which is not confusing, or, simply use transparent color to display nothing...

将此项与其他项一起添加到您的有状态绘图中... ..。

<item android:state_empty="true" android:drawable="@android:color/transparent"/>

因此，您的状态表可以是这样的:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_empty="true" android:drawable="@android:color/transparent"/>
<item android:state_expanded="true" android:drawable="@drawable/my_icon_max" />
<item android:drawable="@drawable/my_icon_min" />
</selector>

如果您正在使用 ExpandableListActivity，那么可以在 onCreate 中按照以下方式设置 group 指示符:

getExpandableListView().setGroupIndicator(getResources().getDrawable(R.drawable.my_group_statelist));

我已经测试过了。

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正如在另一个答案中提到的，因为 Android 将未展开的列表组视为空，所以即使该组有子组，也不会绘制图标。

这个链接为我解决了问题: Http://mylifewithandroid.blogspot.com/2011/06/hiding-group-indicator-for-empty-groups.html

Basically you have to set the default drawable as transparent, move the drawable into your group view as an ImageView and toggle the image in your adapter.

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根据 StrayPointer 的回答和博客中的代码，您可以更加简化代码:

在 xml 中，将以下内容添加到 ExpandableListView:

android:groupIndicator="@android:color/transparent"

Then in the Adapter you do the following:

@Override
protected void bindGroupView(View view, Context paramContext, Cursor cursor, boolean paramBoolean){
**...**


if ( getChildrenCount( groupPosition ) == 0 ) {
indicator.setVisibility( View.INVISIBLE );
} else {
indicator.setVisibility( View.VISIBLE );
indicator.setImageResource( isExpanded ? R.drawable.list_group_expanded : R.drawable.list_group_closed );
}
}

通过使用 setImageResource 方法，您可以使用一行程序完成所有工作。 在适配器中不需要三个 Integer 数组。对于状态展开和折叠，您也不需要 XML 选择器。一切都是通过 Java 完成的。

另外，这种方法还可以显示默认情况下展开组时的正确指示符，这些指示符对博客中的代码不起作用。

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试试这个

for all items

 getExpandableListView().setGroupIndicator(null);

在 xml 中

android:groupIndicator="@null"
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用这个，对我来说非常有效。

<selector xmlns:android="http://schemas.android.com/apk/res/android">


<item android:drawable="@drawable/group_indicator_expanded" android:state_empty="false" android:state_expanded="true"/>
<item android:drawable="@drawable/group_indicator" android:state_empty="true"/>
<item android:drawable="@drawable/group_indicator"/>


</selector>
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在您的代码中，只需将自定义 xml 用于组列表，并将 图片浏览用于 群组指标。

并在 可扩展列表适配器中添加以下数组

private static final int[] EMPTY_STATE_SET = {};
private static final int[] GROUP_EXPANDED_STATE_SET = { android.R.attr.state_expanded };
private static final int[][] GROUP_STATE_SETS = { EMPTY_STATE_SET, // 0
GROUP_EXPANDED_STATE_SET // 1
};

也在 ExpandableListAdapter's方法中添加与下面相同的内容

public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent)
{
if (convertView == null)
{
LayoutInflater infalInflater = (LayoutInflater) this._context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.row_group_list, null);
}


//Image view which you put in row_group_list.xml
View ind = convertView.findViewById(R.id.iv_navigation);
if (ind != null)
{
ImageView indicator = (ImageView) ind;
if (getChildrenCount(groupPosition) == 0)
{
indicator.setVisibility(View.INVISIBLE);
}
else
{
indicator.setVisibility(View.VISIBLE);
int stateSetIndex = (isExpanded ? 1 : 0);
Drawable drawable = indicator.getDrawable();
drawable.setState(GROUP_STATE_SETS[stateSetIndex]);
}
}


return convertView;
}

参考文献: Http://mylifewithandroid.blogspot.in/2011/06/hiding-group-indicator-for-empty-groups.html

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建议你我的解决方案:

1)清除默认群组指示器:

<ExpandableListView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="wrap_content"
android:layout_height="240dp"
android:layout_gravity="start"
android:background="#cccc"
android:groupIndicator="@android:color/transparent"
android:choiceMode="singleChoice"
android:divider="@android:color/transparent"
android:dividerHeight="0dp"
/>

2)在 ExpandableAdapter:

@Override
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
if (convertView == null) {
convertView = new TextView(context);
}
((TextView) convertView).setText(groupItem.get(groupPosition));
((TextView) convertView).setHeight(groupHeight);
((TextView) convertView).setTextSize(groupTextSize);


//create groupIndicator using TextView drawable
if (getChildrenCount(groupPosition)>0) {
Drawable zzz ;
if (isExpanded) {
zzz = context.getResources().getDrawable(R.drawable.arrowup);
} else {
zzz = context.getResources().getDrawable(R.drawable.arrowdown);
}
zzz.setBounds(0, 0, groupHeight, groupHeight);
((TextView) convertView).setCompoundDrawables(null, null,zzz, null);
}
convertView.setTag(groupItem.get(groupPosition));


return convertView;
}
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Simply, you create a new xml layout with height=0 for the hidden group header. 例如，它是‘ group _ list _ item _ empty.xml’

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="0dp">
</RelativeLayout>

然后，正常的组头布局是‘ your _ group _ list _ item _ file.xml’

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="48dp"
android:orientation="horizontal">
...your xml layout define...
</LinearLayout>

最后，只需更新 Adapter Class 中的 getGroupView 方法:

public class MyExpandableListAdapter extends BaseExpandableListAdapter{


//Your code here ...


@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup viewGroup) {
if (Your condition to hide the group header){
if (convertView == null || convertView instanceof LinearLayout) {
LayoutInflater mInflater = (LayoutInflater) context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
convertView = mInflater.inflate(R.layout.group_list_item_empty, null);
}
return convertView;
}else{
if (convertView == null || convertView instanceof RelativeLayout) {
LayoutInflater mInflater = (LayoutInflater) context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
convertView = mInflater.inflate(R.layout.your_group_list_item_file, null);
}
//Your code here ...
return convertView;
}
}
}

重点 : 布局文件(隐藏和普通)的根标记必须不同(如上例 LinearLayout 和 RelativeLayout)

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这可能是从 XML 的另一种方式，设置 android:groupIndicator="@null"

参考链接: https://stackoverflow.com/a/5853520/2624806

小开

您是否尝试过更改 ExpandableListView的属性 android:groupIndicator="@null"？

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convertView.setVisibility(View.GONE) should do the trick.

@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
DistanceHolder holder;
if (convertView == null) {
convertView = LayoutInflater.from(context).inflate(R.layout.list_search_distance_header, parent, false);
if (getChildrenCount(groupPosition)==0) {
convertView.setVisibility(View.GONE);
}
小开

只是想改进 Mihir Trivedi 的答案，你可以把它放在 MyExpandableListAdapter 类中的 getGroupView ()中

    View ind = convertView.findViewById(R.id.group_indicator);
View ind2 = convertView.findViewById(R.id.group_indicator2);
if (ind != null)
{
ImageView indicator = (ImageView) ind;
if (getChildrenCount(groupPosition) == 0)
{
indicator.setVisibility(View.INVISIBLE);
}
else
{
indicator.setVisibility(View.VISIBLE);
int stateSetIndex = (isExpanded ? 1 : 0);


/*toggles down button to change upwards when list has expanded*/
if(stateSetIndex == 1){
ind.setVisibility(View.INVISIBLE);
ind2.setVisibility(View.VISIBLE);
Drawable drawable = indicator.getDrawable();
drawable.setState(GROUP_STATE_SETS[stateSetIndex]);
}
else if(stateSetIndex == 0){
ind.setVisibility(View.VISIBLE);
ind2.setVisibility(View.INVISIBLE);
Drawable drawable = indicator.getDrawable();
drawable.setState(GROUP_STATE_SETS[stateSetIndex]);
}
}
}

...and as for the layout view, this is how my group_items.xml appears to be

<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">


<TextView
android:id="@+id/group_heading"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingLeft="20dp"
android:paddingTop="16dp"
android:paddingBottom="16dp"
android:textSize="15sp"
android:textStyle="bold"/>


<ImageView
android:id="@+id/group_indicator"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@android:drawable/arrow_down_float"
android:layout_alignParentRight="true"
android:paddingRight="20dp"
android:paddingTop="20dp"/>


<ImageView
android:id="@+id/group_indicator2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@android:drawable/arrow_up_float"
android:layout_alignParentRight="true"
android:visibility="gone"
android:paddingRight="20dp"
android:paddingTop="20dp"/>

希望能有所帮助... 记得投赞成票

小开

XML 格式

android:groupIndicator="@null"

在 ExpandableListAdapter-> getGroupView复制下面的代码

if (this.mListDataChild.get(this.mListDataHeader.get(groupPosition)).size() > 0){
if (isExpanded) {
arrowicon.setImageResource(R.drawable.group_up);
} else {
arrowicon.setImageResource(R.drawable.group_down);
}
}
小开

这里张贴的答案会让你的群组指示消失，即使一个群组有孩子。

要解决此问题，请重写组指示符。

首先，将组指示器设置为 null:

    ExpandableListView.setGroupIndicator(null);

然后，转到包含头部的 xml，并添加一个带有绘图工具的 ImageView。

After that, go to your ExpandableListAdapter.java, and in the "getGroupView" section, do the following:

public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
String headerTitle = (String) getGroup(groupPosition);
if (convertView == null) {
LayoutInflater infalInflater = (LayoutInflater) this._context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = infalInflater.inflate(R.layout.list_group, null);
}


TextView lblListHeader = convertView
.findViewById(R.id.lblListHeader); // this is your header


ImageView groupIndicator = convertView.findViewById(R.id.group_indicator); // this is the ImageView included in your xml to override the indicator


if (getChildrenCount(groupPosition) == 0) {
convertView.setVisibility(View.GONE);
lblListHeader.setVisibility(View.GONE);
convertView.setPadding(0,0,0,0); //try not to include padding on your xml, and instead define the padding here.


} else {
convertView.setVisibility(View.VISIBLE);
convertView.setPadding(8,8,8,0);
lblListHeader.setVisibility(View.VISIBLE);
lblListHeader.setTypeface(font);
lblListHeader.setText(headerTitle);
if (isExpanded) { //this is the part where we define our group indicator based on the expanded status of the adapter
groupIndicator.setImageResource(R.drawable.group_indicator_expanded);
} else {
groupIndicator.setImageResource(R.drawable.group_indicator_empty);
}
}


return convertView;
}

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