在此示例中，我们将展示如何使用节头创建ListView。这涉及以下步骤
为List标题和List行创建两个自定义布局 为ListView创建自定义适配器 在您的活动中实例化ListView
我有17个错误。我想用章节标题xamarin android创建listview。 http://javatechig.com/android/listview-with-section-header-in-android
我从java转换为C＃
> - `public class CustomAdapter:BaseAdapter`->does not implement abstract member `android.widget.baseAdapter.getitem(int)`
> - `Android.Widget.BaseAdapter.NotifyDataSetChanged ()`-> An object reference is requered to access non-static member .....
> - `return mData.GetRange(position)`;-> no overload for method 'getrange'take 1 arguments
> - `convertView = mInflater.Inflate(Resource.Layout.textViewHeaderItems, false)`;-> the
> best overloaded method match for ..... has some invalid arguments
> - `convertView.SetTag(holder);`-> no overload for method ... tkae 2 arguments
> - `holder.textView.SetText(mData.get(position))`; type system.collection.generic.list<string> does not contain a defintion
> for 'get'and no extension method 'get'of type
> `system.Colleciton.Generic.List<string>` could be found. Are you
> missing an assembly
public class CustomAdapter:BaseAdapter
{
private const int TYPE_ITEM = 0;
private const int TYPE_SEPARATOR = 1;
private List<String> mData = new List<String>();
private TreeSet sectionHeader = new TreeSet();
private LayoutInflater mInflater;
public CustomAdapter(Context context) {
mInflater = (LayoutInflater) context
.GetSystemService(Context.LayoutInflaterService);
}
public void addItem(String item) {
mData.Add(item);
Android.Widget.BaseAdapter.NotifyDataSetChanged ();
}
public void addSectionHeaderItem(String item) {
mData.Add(item);
sectionHeader.Add(mData.Count - 1);
Android.Widget.BaseAdapter.NotifyDataSetChanged ();
}
public int getItemViewType(int position) {
return sectionHeader.Contains(position) ? TYPE_SEPARATOR : TYPE_ITEM;
}
public int getViewTypeCount() {
return 2;
}
public int getCount() {
return mData.Count;
}
public String getItem(int position) {
return mData.GetRange(position);
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
int rowType = getItemViewType(position);
if (convertView == null) {
holder = new ViewHolder();
switch (rowType) {
case TYPE_ITEM:
convertView = mInflater.Inflate(Resource.Layout.textViewHeaderItems, false);
holder.textView = (TextView) convertView.FindViewById(Resource.Id.textviewHeaderItems);
break;
case TYPE_SEPARATOR:
convertView = mInflater.Inflate(Resource.Layout.textViewItemsSeparator, false);
holder.textView = (TextView) convertView.FindViewById(Resource.Id.textviewItemsSeparator);
break;
}
convertView.SetTag(holder);
} else {
holder = (ViewHolder) convertView.GetTag();
}
holder.textView.SetText(mData.get(position));
return convertView;
}
public class ViewHolder {
public TextView textView;
}
}
答案 0 :(得分：1)
您应该使用＆＃34;搜索＆＃34;在Xamarin的Dev网站上发挥以下问题的作用：
注意：对于像这样的问题，Google或Bing也是您最好的朋友。
Android.Content.Context.LayoutInflaterService
与Context.GetSystemService（String）一起使用，以检索LayoutInflater，以便在此上下文中展开布局资源。
https://developer.xamarin.com/api/field/Android.Content.Context.LayoutInflaterService/
Android.Widget.BaseAdapter.NotifyDataSetChanged
通知附加的观察者基础数据已被更改，反映数据集的任何视图都应自行刷新。
https://developer.xamarin.com/api/member/Android.Widget.BaseAdapter.NotifyDataSetChanged/
Java.Util.TreeSet
TreeSet是SortedSet的一个实现。
答案 1 :(得分：0)
我遇到了一个问题，我最终还是根据this blog post创建了一个ListView部分标题。这就是我做的方式，以防有人遇到同样的问题：
定义标题和将在ListView内填充的列表项的布局：
<强> adapter_expandable_listview_header.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/adapter_expandable_listview_header_textview"
android:layout_width="match_parent"
android:text="Header"
android:textStyle="bold"
android:textSize="14sp"
android:textColor="@color/textColorSecondary"
android:layout_height="wrap_content"
android:layout_margin="16dp" />
</LinearLayout>
<强> adapter_expandable_listview_listitem.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:minWidth="25px"
android:minHeight="25px">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/relativeLayout1"
android:layout_marginLeft="16dp"
android:layout_marginRight="16dp"
android:layout_marginTop="16dp"
android:layout_marginBottom="20dp"
android:descendantFocusability="blocksDescendants">
<TextView
android:text="Rüttenscheider Stern"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/adapter_expandable_listview_listitem_textview1"
android:textSize="16sp"
android:textColor="@color/textColorPrimary" />
<TextView
android:text="Essen"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/adapter_expandable_listview_listitem_textview1"
android:id="@+id/adapter_expandable_listview_listitem_textview2"
android:textSize="14sp" />
<TextView
android:text="Rüttenscheiderstraße"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/adapter_expandable_listview_listitem_textview2"
android:id="@+id/adapter_expandable_listview_listitem_textview3"
android:textSize="14sp" />
<ImageButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:id="@+id/adapter_expandable_listview_listitem_overflow_button"
android:src="@drawable/ic_dots_vertical_grey600_18dp"
android:background="@null" />
</RelativeLayout>
<View
android:layout_width="match_parent"
android:layout_marginLeft="16dp"
android:layout_height="1dp"
android:background="@color/material_grey_300" />
</LinearLayout>
这是ListView的适配器：
<强> SectionedHeaderListViewAdaper.cs
namespace YourNamespace
{
/// <summary>
/// Used to pass groups of objects to the adapter.
/// </summary>
internal class ExpandableItem
{
public string HeaderTitle;
public List<FMNavigationListItem> ChildItems;
}
/// <summary>
/// Used internally by the adapter.
/// </summary>
internal class SectionedHeaderListItem
{
public string HeaderTitle;
public FMNavigationListItem Item;
public SectionedHeaderListItem(string headerTitle, FMNavigationListItem item)
{
HeaderTitle = headerTitle;
Item = item;
}
}
/// <summary>
///
/// </summary>
class SectionedHeaderListViewAdaper : BaseAdapter
{
const int TypeItem = 0;
const int TypeSeperator = 1;
LayoutInflater mLayoutInflater;
List<SectionedHeaderListItem> mDataItems;
List<int> mSectionPositions;
/// <summary>
///
/// </summary>
/// <param name="context"></param>
/// <param name="items"></param>
public SectionedHeaderListViewAdaper(Context context, List<ExpandableItem> items)
{
mLayoutInflater = (LayoutInflater)context.GetSystemService(Context.LayoutInflaterService);
mSectionPositions = new List<int>();
// Sort each item via header title.
List<ExpandableItem> dataItems = items;
dataItems.Sort(delegate (ExpandableItem e1, ExpandableItem e2)
{
return e1.HeaderTitle.CompareTo(e2.HeaderTitle);
});
// Sort each child item alphabetically.
foreach (var d in dataItems)
{
d.ChildItems.Sort(delegate (FMNavigationListItem i1, FMNavigationListItem i2)
{
return i1.DisplayAttributes[0].CompareTo(i2.DisplayAttributes[0]);
});
}
// Merge all items into one big list.
mDataItems = new List<SectionedHeaderListItem>();
int index = 0;
foreach (var expandableItem in dataItems)
{
// Represents a section
mDataItems.Add(new SectionedHeaderListItem(
expandableItem.HeaderTitle,
null));
mSectionPositions.Add(index);
index++;
// Now add the child items for the section
foreach (var dataItem in expandableItem.ChildItems)
{
mDataItems.Add(new SectionedHeaderListItem(
expandableItem.HeaderTitle,
dataItem));
index++;
}
}
}
public override Java.Lang.Object GetItem(int position)
{
return position;
}
public override long GetItemId(int position)
{
return position;
}
public FMNavigationListItem ItemAt(int position)
{
return mDataItems[position].Item;
}
/// <summary>
/// One view for the header and another for
/// the normal cells.
/// </summary>
public override int ViewTypeCount
{
get
{
return 2;
}
}
public override int GetItemViewType(int position)
{
if (mSectionPositions.Contains(position))
return TypeSeperator;
return TypeItem;
}
public override int Count
{
get
{
return mDataItems.Count;
}
}
public override View GetView(int position, View convertView, ViewGroup parent)
{
SectionedHeaderListViewAdaperViewHolder holder = null;
int rowType = GetItemViewType(position);
// Inflate the correct layout
if (convertView == null)
{
holder = new SectionedHeaderListViewAdaperViewHolder();
switch(rowType)
{
case TypeItem:
convertView = mLayoutInflater.Inflate(
Resource.Layout.adapter_expandable_listview_listitem,
null);
break;
case TypeSeperator:
convertView = mLayoutInflater.Inflate(
Resource.Layout.adapter_expandable_listview_header,
null);
break;
}
convertView.Tag = (SectionedHeaderListViewAdaperViewHolder)convertView.Tag;
}
else
{
holder = (SectionedHeaderListViewAdaperViewHolder)convertView.Tag;
}
//Populate UI components
SectionedHeaderListItem item = mDataItems[position];
switch (rowType)
{
case TypeItem:
// Horrible code incomming
holder.DispAttsTextViews = new List<TextView>();
holder.DispAttsTextViews.Add(convertView.FindViewById<TextView>(Resource.Id.adapter_expandable_listview_listitem_textview1));
holder.DispAttsTextViews.Add(convertView.FindViewById<TextView>(Resource.Id.adapter_expandable_listview_listitem_textview2));
holder.DispAttsTextViews.Add(convertView.FindViewById<TextView>(Resource.Id.adapter_expandable_listview_listitem_textview3));
holder.DispAttsTextViews[0].Text = item.Item.DisplayAttributes[0];
holder.DispAttsTextViews[1].Text = item.Item.DisplayAttributes[1];
holder.DispAttsTextViews[2].Text = item.Item.DisplayAttributes[2];
break;
case TypeSeperator:
holder.HeaderTextView = convertView.FindViewById<TextView>(Resource.Id.adapter_expandable_listview_header_textview);
holder.HeaderTextView.Text = item.HeaderTitle;
break;
}
return convertView;
}
}
class SectionedHeaderListViewAdaperViewHolder : Java.Lang.Object
{
public TextView HeaderTextView { get; set; }
public List<TextView> DispAttsTextViews { get; set; }
}
您可以更改FMNavigationListItem对象，因为我在内部使用的是我的数据项。其背后的想法是将数据分组到ExpandableItem个对象中，每个对象都有一个标题标题。适配器获取这些对象并将它们合并到一个大列表中。
您可以查看结果here
