0

肯定是一个菜鸟错误（我昨天下午开始在 WP7 中开发），但我在这上面浪费了很多时间。
我发布了我的课程和我的一小部分代码：

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

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;
    }
}

主页.xaml

<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>

问题是当我将一个或多个项目添加到History.Laps集合时，我的列表框没有刷新并且这些项目不会出现。
但是，如果我删除在线评论，则会// History.Laps.Add(new ChronoLap()...出现此项目，因此稍后会插入其他所有项目。
更多：如果我删除该评论然后写History.Laps.Clear()（在设置绑定之前或之后）绑定不再起作用。如果集合是空的，就好像它会变得疯狂。
实在不明白是什么原因...

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？

4

2 回答 2

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>

而且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..

项目列表.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);
        }
    }
}

我有一个 UIManager.cs 类，在我将数据加载到 UI 给用户之前，我会在其中刷新数据。


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);
        }

    }
}




}

于 2012-08-31T09:36:27.863 回答
0

实际上，我认为为 ChronoLaps 开设单独的课程没有意义。这是我修改 MainPage.xaml.cs 代码的方式，一切似乎都对我有用。

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)});
                          };
        }
    }
于 2012-06-01T22:04:45.447 回答