肯定是一个菜鸟错误（我昨天下午开始在WP7开发），但我浪费了很多时间。
我发布了我的课程和我的代码的一小部分：
public class ChronoLaps : INotifyPropertyChanged
{
private ObservableCollection<ChronoLap> laps = null;
public int CurrentLap
{
get { return lap; }
set
{
if (value == lap) return;
// Some code here ....
ChronoLap newlap = new ChronoLap()
{
// Some code here ...
};
Laps.Insert(0, newlap);
lap = value;
NotifyPropertyChanged("CurrentLap");
NotifyPropertyChanged("Laps");
}
}
public ObservableCollection<ChronoLap> Laps {
get { return laps; }
set
{
if (value == laps) return;
laps = value;
if (laps != null)
{
laps.CollectionChanged += delegate
{
MeanTime = Laps.Sum(p => p.Time.TotalMilliseconds) / (Laps.Count * 1000);
NotifyPropertyChanged("MeanTime");
};
}
NotifyPropertyChanged("Laps");
}
}
}
MainPage.xaml.cs中
public partial class MainPage : PhoneApplicationPage
{
public ChronoLaps History { get; private set; }
private void butStart_Click(object sender, EventArgs e)
{
History = new ChronoLaps();
// History.Laps.Add(new ChronoLap() { Distance = 0 });
LayoutRoot.DataContext = History;
}
}
MainPage.xaml中
<phone:PhoneApplicationPage>
<Grid x:Name="LayoutRoot" Background="Transparent">
<Grid Grid.Row="2">
<ScrollViewer Margin="-5,13,3,36" Height="758">
<ListBox Name="lbHistory" ItemContainerStyle="{StaticResource ListBoxStyle}"
ItemsSource="{Binding Laps}"
HorizontalAlignment="Left" Margin="5,25,0,0"
VerticalAlignment="Top" Width="444">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal">
<TextBlock Text="{Binding Lap}" Width="40" />
<TextBlock Text="{Binding Time}" Width="140" />
<TextBlock Text="{Binding TotalTime}" Width="140" />
<TextBlock Text="{Binding Distance}" />
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</ScrollViewer>
</Grid>
</Grid>
</phone:PhoneApplicationPage>
问题是，当我向History.Laps集合中添加一个或多个项目时，我的列表框不会刷新，并且这些项目不会出现。
但是，如果我删除对// History.Laps.Add(new ChronoLap()...行的评论，则会显示此项目，因此稍后会插入其他所有内容
更多：如果我删除该注释然后写History.Laps.Clear()（在设置绑定之前或之后）绑定不再起作用。如果收集是空的，它就像疯了一样
我真的不明白原因......
更新和解决方案：
如果我搬家
History = new ChronoLaps();
LayoutRoot.DataContext = History;
从butStart_Click到public MainPage()一切都按预期工作
有人可以解释一下原因吗？
答案 0 :(得分：0)
实际上我认为没有必要为ChronoLaps设一个单独的课程。以下是我修改MainPage.xaml.cs代码的方法，一切似乎对我有用。
public partial class MainPage : PhoneApplicationPage
{
public ObservableCollection<ChronoLap> Laps { get; set; }
public double MeanTime { get; set; }
// Constructor
public MainPage()
{
InitializeComponent();
Laps = new ObservableCollection<ChronoLap>();
Laps.CollectionChanged += delegate
{
MeanTime = Laps.Sum(p => p.Time.TotalMilliseconds) / (Laps.Count * 1000);
};
DataContext = this;
Loaded += (s, e) =>
{
Laps.Add(new ChronoLap() {Time = TimeSpan.FromSeconds(1000)});
Laps.Add(new ChronoLap() {Time = TimeSpan.FromSeconds(1000)});
Laps.Add(new ChronoLap() {Time = TimeSpan.FromSeconds(1000)});
};
}
}
答案 1 :(得分：0)
尝试为列表框绑定DataContext和ItemSource ..
我是怎么做的..
<ListBox x:Name="AppList" Background="White" DataContext="{Binding DisplayItem}" SelectionChanged="AppList_SelectionChanged" Height="500" Width="auto">
<ListBox.ItemTemplate>
<DataTemplate>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
我不知道它是否会有所帮助，但我仍然会发布我正在使用的代码..
ItemList.cs
using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Windows.Media.Imaging;
namespace AppHouseLibrary
{
public class ItemList : IComparable
{
private string _name;
public string WidgetName
{
get
{
return _name;
}
set
{
_name = value;
}
}
public int ID
{
get;
set;
}
private BitmapImage _Icon;
public BitmapImage Icon
{
get
{
return _Icon;
}
set
{
_Icon = value;
}
}
//public string arrow { get; set; }
public BitmapImage arrow { get; set; }
public int CompareTo(ItemList other)
{
return this.WidgetName.CompareTo(other.WidgetName);
}
}
}
using System;
using System.ComponentModel;
using System.Collections.ObjectModel;
using System.Windows.Media.Imaging;
using System.Collections.Generic;
using StirLibrary.com.mportal.data.bean;
using com.mportal.utils;
using StirLibrary.com.mportal.utils;
namespace StirLibrary.com.UI
{
public class UIManager : INotifyPropertyChanged
{
private static UIManager instance = null;
private static string TAG = "UIManager";
BitmapImage arrowImage = Utils.returnImage(ImageUtils.ARROW);
public List<ItemList> data = new List<ItemList>();
public static UIManager getInstance()
{
if (instance == null)
{
instance = new UIManager();
}
return instance;
}
private ObservableCollection<ItemList> _displayItem = new ObservableCollection<ItemList>();
public ObservableCollection<ItemList> DisplayItem
{
get
{
return _displayItem;
}
}
private UIManager()
{
}
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(String PropertyName)
{
if (null != PropertyChanged)
{
PropertyChanged(this, new PropertyChangedEventArgs(PropertyName));
}
}
public WidgetBean[] serviceBeanList = null;
public WidgetBean[] wheelBeanList = null;
public WidgetBean getServiceWidgetBean(int selectedIndex)
{
try
{
if (serviceBeanList != null)
{
return serviceBeanList[selectedIndex];
}
}
catch (Exception e)
{
Logger.log(TAG, e.Message);
}
return null;
}
public WidgetBean getWheelWidgetBean(int selectedIndex)
{
try
{
if (wheelBeanList != null)
{
return wheelBeanList[selectedIndex];
}
}
catch (Exception e)
{
Logger.log(TAG, e.Message);
}
return null;
}
public void DisplayCatalog(string[] ServiceDisplayName, string[] WheelDisplayName, BitmapImage[] ServiceIcons, WidgetBean[] ServiceBeanList, WidgetBean[] WheelBeanList)
{
try
{
DisplayItem.Clear();
string disp1 = string.Empty;
string name = ServiceDisplayName[0];
wheelBeanList = WheelBeanList;
serviceBeanList = ServiceBeanList;
for (int i = 0; i < ServiceDisplayName.Length; i++)
{
WidgetBean bean = serviceBeanList[i];
if (bean.isCategory())
{
DisplayItem.Add(new ItemList { WidgetName = ServiceDisplayName[i], Icon = ServiceIcons[i], arrow = arrowImage });
}
else
{
DisplayItem.Add(new ItemList { WidgetName = ServiceDisplayName[i], Icon = ServiceIcons[i] });
}
}
NotifyPropertyChanged("UI");
}
catch (Exception e)
{
Logger.log(TAG,e.Message);
}
}
public void DisplayCatalog(string[] displayName, BitmapImage[] icons, WidgetBean[] beanArray)
{
try
{
serviceBeanList = beanArray;
DisplayItem.Clear();
for (int i = 0; i < displayName.Length; i++)
{
WidgetBean bean = serviceBeanList[i];
if (bean.isCategory())
{
DisplayItem.Add(new ItemList { WidgetName = displayName[i], Icon = icons[i], arrow = arrowImage });
}
else
{
DisplayItem.Add(new ItemList { WidgetName = displayName[i], Icon = icons[i] });
}
}
NotifyPropertyChanged("UI");
}
catch (Exception e)
{
Logger.log(TAG,e.Message);
}
}
}
}