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参考下面的屏幕截图，我有以下视图和视图模型设置来表示进度条下载。当我向这个下载集合添加超过 1 个下载时，下载 1 似乎会覆盖下载 2 的 Progress() 公共属性。

下面的示例是下载 1 正在下载 1MB，它将首先完成，与下载 2 下载 5MB 相比。下载 1 完成后，下载 2（下面的 hello2 示例）进度条就停在那里，但字节仍在后台下载，直到达到 5MB。

如何更改代码以确保下载 1 不会干扰下载 2 的进度条 UI。我尝试将 Progress() 修改为私有，但两个进度条 UI 均未显示

看法

<ItemsControl Name="MyItemsControl" ItemsSource="{Binding GameDownloads}">
        <ItemsControl.ItemTemplate>
            <DataTemplate>
                <Grid  DockPanel.Dock="Right">
                    <Grid.RowDefinitions>
                        <RowDefinition />
                        <RowDefinition />
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="200" />
                        <ColumnDefinition />
                    </Grid.ColumnDefinitions>

                    <TextBlock Grid.Row="0" Grid.Column="0" Text="{Binding GameName}" />
                    <ProgressBar Grid.Row="0" Grid.Column="1"  Minimum="0" Maximum="100" Value="{Binding Progress, Mode=OneWay}" />
                    <TextBlock Grid.Row="1" Grid.Column="1"  Text="{Binding StatusText}" />

                </Grid>

            </DataTemplate>

        </ItemsControl.ItemTemplate>
    </ItemsControl>

下载AppViewModel

Public Class DownloadAppViewModel
Inherits ViewModelBase

Private ReadOnly WC As WebClient
Public Sub New(ByVal Name As String, ByVal URL As String, ByVal FileName As String)
    _gameName = Name
    WC = New WebClient
    AddHandler WC.DownloadFileCompleted, AddressOf DownloadCompleted
    AddHandler WC.DownloadProgressChanged, AddressOf DownloadProgressChanged
    WC.DownloadFileAsync(New Uri(URL), FileName)
End Sub
Private Sub DownloadCompleted(ByVal sender As Object, ByVal e As AsyncCompletedEventArgs)

End Sub
Private Sub DownloadProgressChanged(ByVal sender As [Object], ByVal e As DownloadProgressChangedEventArgs)
    If _totalSize = 0 Then
        _totalSize = e.TotalBytesToReceive
    End If
    DownloadedSize = e.BytesReceived
End Sub

Private _gameName As String

Public Property GameName() As String
    Get
        Return _gameName
    End Get
    Set(ByVal value As String)
        _gameName = value
        Me.OnPropertyChanged("GameName")
    End Set
End Property

Public ReadOnly Property StatusText() As String
    Get
        If _downloadedSize < _totalSize Then
            Return String.Format("Downloading {0} MB of {1} MB", _downloadedSize, _totalSize)
        End If
        Return "Download completed"
    End Get
End Property

Private _totalSize As Long
Private Property TotalSize() As Long
    Get
        Return _totalSize
    End Get
    Set(ByVal value As Long)
        _totalSize = value
        OnPropertyChanged("TotalSize")
        OnPropertyChanged("Progress")
        OnPropertyChanged("StatusText")
    End Set
End Property

Private _downloadedSize As Long
Private Property DownloadedSize() As Long
    Get
        Return _downloadedSize
    End Get
    Set(ByVal value As Long)
        _downloadedSize = value
        OnPropertyChanged("DownloadedSize")
        OnPropertyChanged("Progress")
        OnPropertyChanged("StatusText")
    End Set
End Property


Public ReadOnly Property Progress() As Double
    Get
        If _totalSize <> 0 Then
            Return 100.0 * _downloadedSize / _totalSize
        Else
            Return 0.0
        End If

    End Get

End Property

End Class

在此处输入图像描述

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