Problems setting DisplayIndex during runtime

[Petter]

Hi,

I am using the DisplayIndex property on a RadGridView to set the column order in runtime (through databinding). The problem is that I receive an ArgumentOutOfRangeException when my window is opened.

The XAML looks like the following:

<code style="color: #000;"><</code><code style="color: #069;font-weight: bold;">Telerik:GridViewDataColumn<br></code><code style="color: #000;">TextAlignment="Left"<br></code><code style="color: #000;">TextTrimming="CharacterEllipsis"<br></code><code style="color: #000;">DisplayIndex="{Binding CreatedTimestampColumnIndex}"<br></code><code><font color="#000000">IsReadOnly="True"><br></font></code><code style="color: #008200;"><!-- And more code that sets the header and the CellTemplate with binding etc... --><br></code><code style="color: #000;"></</code><code style="color: #069;font-weight: bold;">Telerik:GridViewDataColumn</code><code style="color: #000;">></code>

        public int CreatedTimestampColumnIndex<br>        {<br>            get<br>            {<br>                return createdTimestampColumnIndex;<br>            }<br> <br>            set<br>            {<br>                createdTimestampColumnIndex = value;<br>                OnPropertyChanged("CreatedTimestampColumnIndex");<br>            }<br>        }

I've verified that I do get a callback to my property methods in the ViewModel. If I set the DisplayIndex to a static value in the XAML (i.e. DisplayIndex="3") works fine.

Why doesn't this work with data binding?

Details:
.NET version: 4.5
Telerik version. 2013.Q1

Would really appreciate a solution to this, thanks!

[Petter]

Looked like my code blocks were messed up. Here's a cleaner version:

<Telerik:GridViewDataColumn
TextAlignment="Left"
TextTrimming="CharacterEllipsis"
DisplayIndex="{Binding CreatedTimestampColumnIndex}"
IsReadOnly="True">

<!-- And more code that sets the header and the CellTemplate with binding etc... -->
</Telerik:GridViewDataColumn>

and

public int CreatedTimestampColumnIndex
get
{
return createdTimestampColumnIndex;
}
set
{
createdTimestampColumnIndex = value;
OnPropertyChanged("CreatedTimestampColumnIndex");
}

[Dimitrina]

Hi,

Is the value of the CreatedTimestampColumnIndex a valid DisplayIndex? I have tested it on my side and as soon as the DisplayIndex is a valid value, then it works fine. 
You say that if you set DisplayIndex="3" it works fine. Is the value of CreatedTimestampColumnIndex also 3 when it raises the exception?

Regards,
Didie
Telerik

[Dimitrina]

Hello,

I have also attached my test solution as a reference.

Regards,
Didie
Telerik

[Petter]

Hi Didie,

Thanks for your response and the project (works for me). But I still get the OutOfRange exception when the value (which is valid) is taken through binding instead of a static value. More details:

This works:

                        <Telerik:GridViewDataColumn
                            Width="105"
                            MinWidth="105"
                            IsSortable="True"
                            HeaderTextAlignment="Center"
                            IsFilterable="False"
                            TextAlignment="Left"
                            TextTrimming="CharacterEllipsis"
                            IsReadOnly="True"
                            DataMemberBinding="{Binding uld_insert_date_time}"
                            DisplayIndex="3"
                            Header="Created">

                            <Telerik:GridViewColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBlock
                                        Text="{Binding uld_insert_date_time, StringFormat={}{0:dd-MMM-yyyy HH:mm}}"/>
                                </DataTemplate>
                            </Telerik:GridViewColumn.CellTemplate>

                        </Telerik:GridViewDataColumn>

This gives me the exception:

                        <Telerik:GridViewDataColumn
                            Width="105"
                            MinWidth="105"
                            IsSortable="True"
                            HeaderTextAlignment="Center"
                            IsFilterable="False"
                            TextAlignment="Left"
                            TextTrimming="CharacterEllipsis"
                            IsReadOnly="True"
                            DataMemberBinding="{Binding uld_insert_date_time}"
                            DisplayIndex="{Binding CreatedTimestampColumnIndex}"
                            Header="Created">

                            <Telerik:GridViewColumn.CellTemplate>
                                <DataTemplate>
                                    <TextBlock
                                        Text="{Binding uld_insert_date_time, StringFormat={}{0:dd-MMM-yyyy HH:mm}}"/>
                                </DataTemplate>
                            </Telerik:GridViewColumn.CellTemplate>

                        </Telerik:GridViewDataColumn>

... and I have verified that the returned value from the following method:

        public int CreatedTimestampColumnIndex
        {
            get
            {
                return createdTimestampColumnIndex;
            }

            set
            {
                createdTimestampColumnIndex = value;
                OnPropertyChanged("CreatedTimestampColumnIndex");
            }
        }

is 3 (I have 17 columns).

(And yes, I realize that I used a Telerik:GridViewColumn and not Telerik:GridViewDataColumn in my original post (sorry about that), but I changed the column in your project to a Telerik:GridViewDataColumn and it worked fine).

The exception occurs when the window is opened.

The only significant difference between your and my project I can think of is the following:

- In my xaml.cs file for my view, I set the data context for the entire view to the view model (this.DataContext = ViewModel; after the call to InitializeComponent();). You set it for the grid (DataContext="{StaticResource MyViewModel}") in the xaml file.

But shouldn't really matter.

Any ideas would be most helpful, thanks!

/ Petter

[Petter]

Oops, when I changed the sequence of the calls in the xaml.cs to the following:

            this.DataContext = ViewModel;
            InitializeComponent();

It started working.

But now, when I set the DisplayIndex value of my to columns Created and Last updated to 17 and 3 respectively, the DisplayIndex property is not called for the latter, i.e.

CreatedTimestampColumnIndex = 17;
UpdatedTimestampColumnIndex = 3;

will enforce the Created column to change column index, but not the Last updated. I simply never get a callback to

        public int UpdatedTimestampColumnIndex
        {
            get
            {
                return updatedTimestampColumnIndex;
            }

            set
            {
                updatedTimestampColumnIndex = value;
                OnPropertyChanged("UpdatedTimestampColumnIndex");
            }

despite the call to OnPropertyChanged.

Is this becuase the DisplayIndex of it already changed since I first changed the DisplayIndex of the Created column, this forcing the Last updated column to "automatically" change DisplayIndex? How do I deal with this?

[Petter]

I got it working now.

Solution: The binding mode must explicitly be set to TwoWay (this is usually default).

[Dimitrina]

Hello,

I am glad to hear you got it working fine!

Regards,
Didie
Telerik