C# 在Windows Phone 7或Windows Phone 8中使用CollectionView进行LongListSelector分组

C# 在Windows Phone 7或Windows Phone 8中使用CollectionView进行LongListSelector分组,c#,windows-phone-7,windows-phone-8,collectionviewsource,C#,Windows Phone 7,Windows Phone 8,Collectionviewsource,我面临的问题与下面标签中列出的问题相同 我使用以下代码将LongListSelector与分组绑定 CollectionViewSource cv = new CollectionViewSource(); cv.Source = comments; cv.GroupDescriptions.Add(new PropertyGroupDescription("Filter")); listSelector.HideEmptyGroups = true; listSelector.ItemsS

我面临的问题与下面标签中列出的问题相同

我使用以下代码将LongListSelector与分组绑定

CollectionViewSource cv = new CollectionViewSource();
cv.Source = comments;
cv.GroupDescriptions.Add(new PropertyGroupDescription("Filter"));

listSelector.HideEmptyGroups = true;
listSelector.ItemsSource = cv.View.Groups;

但它没有显示任何内容。有人能帮我吗?

它不支持ICollectionView的设计。该控件期望组实现IEnumerable,而CollectionViewGroup没有实现。CollectionViewGroup是所有ICollectionView组的基类

因此,您必须围绕ICollectionView制作一个包装器,以支持LongListSelector期望的接口或修改LongListSelector源代码

下面是我快速而肮脏的包装器实现:

namespace PresentationModel
{
    using System;
    using System.Collections;
    using System.Collections.Generic;
    using System.Collections.Specialized;
    using System.ComponentModel;
    using System.Linq;
    using System.Windows.Data;

    public class GroupViewItem : IList, INotifyCollectionChanged
    {
        private readonly CollectionViewGroup group;

        public GroupViewItem(CollectionViewGroup group)
        {
            this.group = group;
            ((INotifyCollectionChanged)this.group.Items).CollectionChanged += HandleCollectionViewGroupChanged;

        }

        private void HandleCollectionViewGroupChanged(object sender, NotifyCollectionChangedEventArgs e)
        {
            OnCollectionChanged(e);
        }

        public object Name { get { return this.group.Name; } }

        public int Count { get { return this.group.ItemCount; } }

        public IEnumerator GetEnumerator()
        {
            return this.group.Items.GetEnumerator();
        }

        public event NotifyCollectionChangedEventHandler CollectionChanged;

        private void OnCollectionChanged(NotifyCollectionChangedEventArgs args)
        {
            var collectionChanged = this.CollectionChanged;
            if (collectionChanged != null)
            {
                collectionChanged(this, args);
            }
        }

        int IList.Add(object value)
        {
            throw new NotSupportedException();
        }

        void IList.Clear()
        {
            throw new NotSupportedException();
        }

        bool IList.Contains(object value)
        {
            throw new NotSupportedException();
        }

        int IList.IndexOf(object value)
        {
            throw new NotSupportedException();
        }

        void IList.Insert(int index, object value)
        {
            throw new NotSupportedException();
        }

        bool IList.IsFixedSize
        {
            get
            {
                throw new NotSupportedException();
            }
        }

        bool IList.IsReadOnly
        {
            get
            {
                throw new NotSupportedException();
            }
        }

        void IList.Remove(object value)
        {
            throw new NotSupportedException();
        }

        void IList.RemoveAt(int index)
        {
            throw new NotSupportedException();
        }

        object IList.this[int index]
        {
            get
            {
                throw new NotSupportedException();
            }
            set
            {
                throw new NotSupportedException();
            }
        }

        void ICollection.CopyTo(System.Array array, int index)
        {
            throw new NotSupportedException();
        }

        bool ICollection.IsSynchronized
        {
            get
            {
                throw new NotSupportedException();
            }
        }

        object ICollection.SyncRoot
        {
            get
            {
                throw new NotSupportedException();
            }
        }
    }

    public class GroupView : IEnumerable, INotifyCollectionChanged
    {
        private readonly ICollectionView collectionView;
        private readonly List<GroupViewItem> items;

        public GroupView(ICollectionView collectionView)
        {
            this.items = new List<GroupViewItem>();

            this.collectionView = collectionView;
            ((INotifyCollectionChanged)this.collectionView.Groups).CollectionChanged += HandleCollectionViewGroupsChanged;
            ResetGroups(notify: false);
        }

        private void HandleCollectionViewGroupsChanged(object sender, NotifyCollectionChangedEventArgs e)
        {
            switch (e.Action)
            {
                case NotifyCollectionChangedAction.Add:
                    AddGroups(e);
                    break;
                case NotifyCollectionChangedAction.Remove:
                    RemoveGroups(e);
                    break;
                case NotifyCollectionChangedAction.Replace:
                    ReplaceGroups(e);
                    break;
                case NotifyCollectionChangedAction.Reset:
                    ResetGroups();
                    break;
            }
        }

        private IList<GroupViewItem> AddGroups(NotifyCollectionChangedEventArgs e, bool notify = true)
        {
            var newGroups = e.NewItems
                .Cast<CollectionViewGroup>()
                .Select(cvg => new GroupViewItem(cvg))
                .ToArray();

            this.items.InsertRange(e.NewStartingIndex, newGroups);

            if (notify)
            {
                for (var i = 0; i != newGroups.Length; ++i)
                {
                    OnCollectionChanged(new NotifyCollectionChangedEventArgs(
                        NotifyCollectionChangedAction.Add,
                        newGroups[i],
                        e.NewStartingIndex + i));
                }
            }

            return newGroups;
        }

        private IList<GroupViewItem> RemoveGroups(NotifyCollectionChangedEventArgs e, bool notify = true)
        {
            var oldGroups = this.items.GetRange(e.OldStartingIndex, e.OldItems.Count);

            this.items.RemoveRange(e.OldStartingIndex, e.OldItems.Count);

            if (notify)
            {
                for (var i = 0; i != oldGroups.Count; ++i)
                {
                    OnCollectionChanged(new NotifyCollectionChangedEventArgs(
                        NotifyCollectionChangedAction.Remove,
                        oldGroups[i],
                        e.OldStartingIndex + i));
                }
            }

            return oldGroups;
        }

        private void ReplaceGroups(NotifyCollectionChangedEventArgs e)
        {
            var oldGroups = RemoveGroups(e, notify: false);
            var newGroups = AddGroups(e, notify: false);

            if (oldGroups.Count != newGroups.Count)
            {
                OnCollectionChanged(new NotifyCollectionChangedEventArgs(
                    NotifyCollectionChangedAction.Reset));
            }
            else
            {
                for (var i = 0; i != newGroups.Count; ++i)
                {
                    OnCollectionChanged(new NotifyCollectionChangedEventArgs(
                        NotifyCollectionChangedAction.Replace,
                        newGroups[i], oldGroups[i],
                        e.NewStartingIndex + i));
                }
            }
        }

        private void ResetGroups(bool notify = true)
        {
            this.items.Clear();
            this.items.AddRange(
                this.collectionView.Groups
                    .Cast<CollectionViewGroup>()
                    .Select(cvg => new GroupViewItem(cvg)));

            if (notify)
            {
                OnCollectionChanged(new NotifyCollectionChangedEventArgs(
                    NotifyCollectionChangedAction.Reset));
            }
        }

        public event NotifyCollectionChangedEventHandler CollectionChanged;

        public IEnumerator GetEnumerator()
        {
            return this.items.GetEnumerator();
        }

        private void OnCollectionChanged(NotifyCollectionChangedEventArgs args)
        {
            var collectionChanged = this.CollectionChanged;
            if (collectionChanged != null)
            {
                collectionChanged(this, args);
            }
        }
    }
}
namespace PresentationModel
{
使用制度;
使用系统集合;
使用System.Collections.Generic;
使用System.Collections.Specialized;
使用系统组件模型;
使用System.Linq;
使用System.Windows.Data;
公共类GroupViewItem:IList,INotifyCollectionChanged
{
私有只读集合视图组;
公共组视图项(CollectionViewGroup组)
{
this.group=组;
((INotifyCollectionChanged)this.group.Items).CollectionChanged+=HandleCollectionViewGroupChanged;
}
私有void HandleCollectionViewGroupChanged(对象发送方,NotifyCollectionChangedEventArgs e)
{
非集合更改(e);
}
公共对象名称{get{返回this.group.Name;}}
公共整数计数{get{返回this.group.ItemCount;}}
公共IEnumerator GetEnumerator()
{
返回此.group.Items.GetEnumerator();
}
公共事件通知CollectionChangedEventHandler CollectionChanged;
CollectionChanged上的私有void(NotifyCollectionChangedEventArgs args)
{
var collectionChanged=this.collectionChanged;
如果(collectionChanged!=null)
{
collectionChanged(此参数为args);
}
}
int IList.Add(对象值)
{
抛出新的NotSupportedException();
}
void IList.Clear()
{
抛出新的NotSupportedException();
}
bool IList.Contains(对象值)
{
抛出新的NotSupportedException();
}
int IList.IndexOf(对象值)
{
抛出新的NotSupportedException();
}
void IList.Insert(int索引,对象值)
{
抛出新的NotSupportedException();
}
bool IList.IsFixedSize
{
得到
{
抛出新的NotSupportedException();
}
}
bool-IList.IsReadOnly
{
得到
{
抛出新的NotSupportedException();
}
}
void IList.Remove(对象值)
{
抛出新的NotSupportedException();
}
void IList.RemoveAt(int索引)
{
抛出新的NotSupportedException();
}
对象IList。此[int索引]
{
得到
{
抛出新的NotSupportedException();
}
设置
{
抛出新的NotSupportedException();
}
}
void ICollection.CopyTo(System.Array数组,int索引)
{
抛出新的NotSupportedException();
}
布尔ICollection.IsSynchronized
{
得到
{
抛出新的NotSupportedException();
}
}
对象ICollection.SyncRoot
{
得到
{
抛出新的NotSupportedException();
}
}
}
公共类组视图:IEnumerable,INotifyCollectionChanged
{
私有只读ICollectionView collectionView;
私有只读列表项;
公共组视图(ICollectionView集合视图)
{
this.items=新列表();
this.collectionView=collectionView;
((INotifyCollectionChanged)this.collectionView.Groups)。CollectionChanged+=HandleCollectionViewGroupsChanged;
重置组(通知:false);
}
私有void HandleCollectionViewGroupsChanged(对象发送方,NotifyCollectionChangedEventArgs e)
{
开关(电动)
{
案例NotifyCollectionChangedAction。添加:
各组(e);
打破
案例NotifyCollectionChangedAction。删除:
移除组(e);
打破
案例通知收集更改操作。替换:
三组(e);
打破
案例通知CollectionChangedAction.Reset:
重置组();
打破
}
}
私有IList AddGroups(NotifyCollectionChangedEventArgs e,bool notify=true)
{
var newGroups=e.NewItems
.Cast()
.选择(cvg=>new GroupViewItem(cvg))
.ToArray();
this.items.InsertRange(例如NewStartingIndex、newGroups);
如果(通知)
{
对于(变量i=0;i!=newGroups.Length;++i)
{
OnCollectionChanged(新建NotifyCollectionChangedEventArgs(
NotifyCollectionChangedAction.Add,
新集团[i],
e、 新闻开始索引+i);
}
}
返回新组;
}
私有IList RemoveGroups(NotifyCollectionChangedEventArgs e,bool notify=true)
{
var oldGroups=this.items.GetRange(e.OldStartingIndex,e.OldItems.Count);
this.items.RemoveRange(e.OldStartingIndex,e.OldItems.Count);
我