我遇到了longlistselector问题，这有点奇怪......我正在多个Pivot页面上异步读取列表，如果我不更改数据库直到结果列表读取，它将成功创建联系人列表（在枢轴项目编号3的长列表选择器中），当我转到该枢轴时，联系人列表显示没有任何问题，但是当我打开页面并在创建长列表选择器之前更改枢轴时asychronous函数返回结果并填充第3号轴上的longlistselector，联系人不会更新（当我转到第3段时，没有显示任何联系人）......
我会发布我的代码，以便您可以更清楚地了解情况，并可能弄清楚发生了什么。 该代码基于PhoneToolkit LongListSelector示例（好友列表）
public partial class Feeds : PhoneApplicationPage
{
bool isLoading = false;
bool loadingFilmates = true;
public Feeds()
{
InitializeComponent();
// ...
Loaded += FeedsPage_Loaded;
SystemTray.ProgressIndicator = new ProgressIndicator();
DataContext = this;
getFilmatesList();
longlistFilmates.SelectionChanged += FilmateSelectionChanged;
// ...
}
private async void getFilmatesList()
{
Feed userFilmates = await Feed.GetFilmates(App.Current.AppUser, App.Current.WSConfig, 0, "", 10000); // read feeds from webservice
Filmates = AlphaKeyGroup<StayObjectFilmates>.CreateGroups(AllFilmates.GetCurrent(userFilmates), CultureInfo.CurrentUICulture, (p) => { return p.Name; }, true);
//longlistFilmates.Visibility = System.Windows.Visibility.Collapsed;
longlistFilmates.Visibility = System.Windows.Visibility.Visible;
longlistFilmates.UseLayoutRounding = true;
pivotFeed.Visibility = System.Windows.Visibility.Collapsed;
pivotFeed.Visibility = System.Windows.Visibility.Visible;
}
}
请注意，我甚至尝试在加载时更改Visibility属性以强制在屏幕上重新渲染，但它不起作用。
这是StayObjectFilmates类：
public class StayObjectFilmates
{
public string Img { get; private set; }
public string Name { get; private set; }
public string UserId { get; private set; }
public string Id { get; set; }
public User user { get; set; }
public StayObjectFilmates()
{
//Img = "";
//Name = "";
//Id = "";
}
public StayObjectFilmates(string p_img, string p_name, string p_Id)
{
Img = p_img;
Name = p_name;
UserId = p_Id;
}
public StayObjectFilmates(User p_user)
{
user = p_user;
}
public static string GetNameKey(StayObjectFilmates filmate)
{
char key = char.ToLower(filmate.Name[0]);
if (key < 'a' || key > 'z')
{
key = '#';
}
return key.ToString();
}
public static int CompareByName(object obj1, object obj2)
{
StayObjectFilmates p1 = (StayObjectFilmates)obj1;
StayObjectFilmates p2 = (StayObjectFilmates)obj2;
int result = p1.Name.CompareTo(p2.Name);
if (result == 0)
{
result = p1.Img.CompareTo(p2.Img);
}
return result;
}
}
这是AllFilmates课程：
public class AllFilmates : IEnumerable<StayObjectFilmates>
{
private static Dictionary<int, StayObjectFilmates> _filmateLookup;
private static AllFilmates _instance;
private Feed filmates;
// public List<StayObjectFilmates> Filmates { get; private set; }
public static AllFilmates GetCurrent(Feed p_filmates)
{
if (_instance == null)
{
_instance = new AllFilmates();
}
_instance.filmates = p_filmates;
return _instance;
}
public static AllFilmates Current
{
get
{
return _instance ?? (_instance = new AllFilmates());
}
}
public StayObjectFilmates this[int index]
{
get
{
StayObjectFilmates filmate;
_filmateLookup.TryGetValue(index, out filmate);
return filmate;
}
}
#region IEnumerable<StayObjectFilmates> Members
public IEnumerator<StayObjectFilmates> GetEnumerator()
{
EnsureData();
return _filmateLookup.Values.GetEnumerator();
}
#endregion
#region IEnumerable Members
System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
{
EnsureData();
return _filmateLookup.Values.GetEnumerator();
}
#endregion
private void EnsureData()
{
if (_filmateLookup == null)
{
_filmateLookup = new Dictionary<int, StayObjectFilmates>();
if (filmates != null)
{
int i = 0;
foreach (var item in filmates.itemsList)
{
User friend = item as User;
string userphoto = (friend.photo == null) ? "Images/avatar.jpg" : friend.photo;
StayObjectFilmates f = new StayObjectFilmates(userphoto, friend.fullName, i.ToString());
_filmateLookup[i] = f;
i++;
}
}
}
}
}
这是AlphaKeyGroup.cs文件：
public class AlphaKeyGroup<T> : List<T>
{
private const string GlobeGroupKey = "\uD83C\uDF10";
/// <summary>
/// The delegate that is used to get the key information.
/// </summary>
/// <param name="item">An object of type T</param>
/// <returns>The key value to use for this object</returns>
public delegate string GetKeyDelegate(T item);
/// <summary>
/// The Key of this group.
/// </summary>
public string Key { get; private set; }
/// <summary>
/// Public constructor.
/// </summary>
/// <param name="key">The key for this group.</param>
public AlphaKeyGroup(string key)
{
Key = key;
}
public AlphaKeyGroup(IGrouping<string, T> grouping)
{
Key = grouping.Key;
this.AddRange(grouping);
}
/// <summary>
/// Create a list of AlphaGroup<T> with keys set by a SortedLocaleGrouping.
/// </summary>
/// <param name="slg">The </param>
/// <returns>Theitems source for a LongListSelector</returns>
private static List<AlphaKeyGroup<T>> CreateGroups(SortedLocaleGrouping slg)
{
List<AlphaKeyGroup<T>> list = new List<AlphaKeyGroup<T>>();
foreach (string key in slg.GroupDisplayNames)
{
if (key == "...")
{
list.Add(new AlphaKeyGroup<T>(GlobeGroupKey));
}
else
{
list.Add(new AlphaKeyGroup<T>(key));
}
}
return list;
}
/// <summary>
/// Create a list of AlphaGroup<T> with keys set by a SortedLocaleGrouping.
/// </summary>
/// <param name="items">The items to place in the groups.</param>
/// <param name="ci">The CultureInfo to group and sort by.</param>
/// <param name="getKey">A delegate to get the key from an item.</param>
/// <param name="sort">Will sort the data if true.</param>
/// <returns>An items source for a LongListSelector</returns>
public static List<AlphaKeyGroup<T>> CreateGroups(IEnumerable<T> items, CultureInfo ci, GetKeyDelegate getKey, bool sort)
{
SortedLocaleGrouping slg = new SortedLocaleGrouping(ci);
List<AlphaKeyGroup<T>> list = CreateGroups(slg);
foreach (T item in items)
{
int index = 0;
if (slg.SupportsPhonetics)
{
//check if your database has yomi string for item
//if it does not, then do you want to generate Yomi or ask the user for this item.
//index = slg.GetGroupIndex(getKey(Yomiof(item)));
}
else
{
index = slg.GetGroupIndex(getKey(item));
}
if (index >= 0 && index < list.Count)
{
list[index].Add(item);
}
}
if (sort)
{
foreach (AlphaKeyGroup<T> group in list)
{
group.Sort((c0, c1) => { return ci.CompareInfo.Compare(getKey(c0), getKey(c1)); });
}
}
return list;
}
}
FilmatesInGroup.cs和FilmatesByName.cs与PhoneToolKit示例中的PeopleInGroup.cs和PeopleByFirstName.cs相同，并且名称已经过修改。 longlistFilmates LongListSelector对象直接插入PivotItem no.3（没有Grid，没有ScrollView）
提前感谢您的帮助！