c＃wpf DataGrid：以编程方式更改绑定列上的图像源

Question

I have a SQL Database with computers names bound to a DataGrid Like This:

                <Grid.Resources>
            <ResourceDictionary>
                <local:FileIconConverter2 x:Key="FileIconConverter2"/>
                <BitmapImage x:Key="Image-Unknown" UriSource="../Images/Status-Unknown.ico" />
                <BitmapImage x:Key="Image-Good" UriSource="../Images/Status-Good.ico" />
            </ResourceDictionary>
        </Grid.Resources>
    <DataGrid Name="datagrid1" AutoGenerateColumns="False" IsReadOnly="True" SelectionChanged="datagrid1_SelectionChanged">
<DataGrid.Columns>
    <DataGridTemplateColumn Header="Status" >
        <DataGridTemplateColumn.CellTemplate>
            <DataTemplate>
                <Image Source="{StaticResource Image-Unknown}"/>
            </DataTemplate>
        </DataGridTemplateColumn.CellTemplate>
    </DataGridTemplateColumn>
    <DataGridTextColumn Header="Date d m yyyy" Binding="{Binding 'Date d m yyyy'}"/>
    <DataGridTextColumn Header="Device Name" Binding="{Binding DeviceName}"/>
    <DataGridTextColumn Header="OS" Binding="{Binding OS}"/>
    <DataGridTextColumn Header="OS" Binding="{Binding Model}"/>
    <DataGridTextColumn Header="EOL" Binding="{Binding DeviceAge}"/>
    <DataGridTextColumn Header="Location" Binding="{Binding Location}"/>
    <DataGridTextColumn Header="IP" Binding="{Binding IP}"/>
    <DataGridTextColumn Header="MAC" Binding="{Binding Mac}"/>
</DataGrid.Columns>

What I am trying to do is when you click on a row, have the status column image update to show if the computer is online by changing the image. The Status column is not in the database. whenever I try changing the content of the status column I get [icon] or [bitmap] text, not an image, and if I scroll down then back up the image defaults back.

Here is the Any Suggestions?

Edit: Where the table can contain 100's of entries, I only want to check the online status when a row is selected. So I'm trying to use SelectionChanged event on datagrid1 like this:

    private void datagrid1_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        DataGrid dataGrid = sender as DataGrid;
        DataGridRow row = (DataGridRow)dataGrid.ItemContainerGenerator.ContainerFromIndex(dataGrid.SelectedIndex);
        DataGridCell rowColumn = dataGrid.Columns[2].GetCellContent(row).Parent as DataGridCell;
        string CellValue = ((TextBlock)rowColumn.Content).Text;
        log.Warn(CellValue);

        //myclass.GetCell(datagrid1, row.GetIndex(), 0).Content = Properties.Resources.Status_Good;
        myclass.GetCell(datagrid1, row.GetIndex(), 0).Content = (Bitmap)System.Drawing.Image.FromFile(@".\Images\Status-good.ico");

    }

The myClass.GetCell code comes from this post.

But, as you can see in this screen shot, I only get text and not the image. Screen Shot

Answer 1

Did you try to add triggers to your image ?

<DataGridTemplateColumn Header="Status" >
    <DataGridTemplateColumn.CellTemplate>
        <DataTemplate>
            <Image >
               <Image.Style>
                   <Setter Property="Source" Value="{StaticResource Image-Unknown}"/>
                   <Style.Triggers>
                     <DataTrigger Binding="{Binding YourModelPropertyStatus}" Value="true">
                          <Setter Property="Source" Value="{StaticResource Image-Good}"/>
                     </DataTrigger>
                   </Style.Triggers>
               </Image.Style>
            </Image> 
        </DataTemplate>
    </DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>

Edit :

Solution 1 (the closest to your existing code)

Rather than searching and editing the cell content in code behind (which is really bad practice), use the arguments given by the selectionChanged callback like e.AddedItems and e.RemovedItems wich will give you the business models (representing your devices) wich have been added and removed. Something like

        foreach (var addedItem in e.AddedItems)
        {
            var device = (Device) addedItem;
            device.CheckStatus();
        }
        foreach (var remItem in e.RemovedItems)
        {
            var device = (Device)remItem;
            device.SetToUnknown();
        }

Where CheckStatus is the method that check the online status and will set the flag YourModelPropertyStatus to true of false (and thus active the triggers described above)

Solution 2 (the cleanest way)

The best and cleanest way to acheive what you want, keeping the triggers solution in the XAML, is to manage everything on your view model using a CollectionView to wrapp your devices collection. In your XAML DataGrid set the IsSynchronizedToCurrentItem=true and then, in your view model, subscribe to CurrentChanged event and in the callback get the CurrentItem of the CollectionView and call the CheckStatus(); that can be either in your view model or in your device object.