How to change data in a Silverlight DataContext Object - silverlight

Question

I have a datacontext object that displays a list of uploaded files, and number of copies. So far, the user can click an edit icon that is in each row, and retrieve the data in that row, but I do not know how to change any data.
Here is the button event for the 'change details' dialog on the main page:
private void Image_MouseLeftButtonUp_1(object sender, MouseButtonEventArgs e)
{
Image b = sender as Image;
FileReceivedItem fi = b.DataContext as FileReceivedItem;
string fileCopies = fi.fileCopies;
string fileName = fi.FileName;
DetailsWindow detailsDlg = new DetailsWindow(fileCopies, fileName);
detailsDlg.Show();
detailsDlg.Closed += new EventHandler(detailsWnd_Closed);
}
public DetailsWindow detailsDlg;
void detailsWnd_Closed(object sender, EventArgs e)
{
MessageBox.Show("I want to change fileCopies here");
}
The relevant portions of the XAML:
<ListBox ScrollViewer.HorizontalScrollBarVisibility="Hidden" ItemsSource="{StaticResource FileReceivedItem}" Name="filesReceivedList" HorizontalAlignment="Left" Grid.Row="1" Grid.Column="1" Background="White" Margin="12,23,0,0"
VerticalAlignment="Top" Width="411" Height="175" Loaded="filesReceivedList_Loaded">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel Width="404" Height="19" Orientation="Horizontal" >
<TextBlock x:Name="ListFileName" Text="{Binding FileName}" Width="283" VerticalAlignment="Center">
<ToolTipService.ToolTip>
<ToolTip Content="{Binding FileName}"></ToolTip>
</ToolTipService.ToolTip>
</TextBlock>
<TextBlock Text="{Binding fileCopies}" Width="50" VerticalAlignment="Center"/>
<TextBlock Text="{Binding FileID}" Width="0" Visibility="Collapsed" VerticalAlignment="Center"/>
<Image Source="images/Edit.png" MouseLeftButtonUp="Image_MouseLeftButtonUp_1" Width="20" Margin="0 0 0 0">
<ToolTipService.ToolTip>
<ToolTip Content="Edit"></ToolTip>
</ToolTipService.ToolTip>
</Image>
<TextBlock Text="" Width="10" />
<Image Source="images/Delete.png" MouseLeftButtonUp="Image_MouseLeftButtonUp" >
<ToolTipService.ToolTip>
<ToolTip Content="Delete"></ToolTip>
</ToolTipService.ToolTip>
</Image>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Let me know if any important pieces of code are missing. I'm not sure how the data source works exactly.

Answer 1

I eventually got it to work. Pretty straightforward. I just haven't used SL in ahwile. This is what I did, although there might be a better way that someone might provide as a better answer:
void detailsWnd_Closed(object sender, EventArgs e)
{
changeFileCopies(detailsDlg.FileName, detailsDlg.nCopies.Text);
}
public void changeFileCopies(string filename, string newCopies)
{
var row = (FileReceivedItem)filesReceivedDataSource.Where(x => x.FileName == filename).FirstOrDefault();
row.fileCopies = newCopies;
filesReceivedList.ItemsSource = null;
this.filesReceivedList.ItemsSource = filesReceivedDataSource;
}