RadBinaryImage in RadTreeList

[Jon]

I normally use a grid along with a gridbinaryimagecolumn to display images from the database in my grid.

How do I go about doing the same thing in a RadTreeList?  I've tried with a template column and a radbinaryimage but can't get a way of storing the database driven image into a hidden column.

Any suggestions?

Regards

Jon

[Konstantin Dikov]

Hello Jon,

Since RadTreeList does not have BinaryImageColumn, what you could do is to use TreeListTemplateColumn and place RadBinaryImage control in the ItemTemplate. Following is a simple example demonstrating such approach, where the BinaryImage field is of byte[] type:

<telerik:RadTreeList runat="server" ID="RadTreeList1" DataKeyNames="ID" ParentDataKeyNames="ParentID"
     OnNeedDataSource="RadTreeList1_NeedDataSource" AutoGenerateColumns="false">
    <Columns>
        <telerik:TreeListBoundColumn DataField="ID" HeaderText="ID" UniqueName="ID">
        </telerik:TreeListBoundColumn>
        <telerik:TreeListTemplateColumn>
            <ItemTemplate>
                <telerik:RadBinaryImage runat="server" ID="RadBinaryImage1" DataValue='<%#Eval("BinaryImage") %>' />
            </ItemTemplate>
        </telerik:TreeListTemplateColumn>
    </Columns>
</telerik:RadTreeList>

Hope this helps.


Regards,
Konstantin Dikov
Telerik

 

 

[Jon]

Hi Konstantin,

Ah yes - I missed that one - I'll put it down to the bad cold that I had last week!

What is the best approach for handling a Null field value in this instance?  

Regards

Jon

[Konstantin Dikov]

Hello Jon,

For handling null values you could use the following approach:

<telerik:RadBinaryImage runat="server" ID="RadBinaryImage1" DataValue='<%#  Eval("BinaryImage") is DBNull ? new byte[0] : Eval("BinaryImage")   %>' />

However, since the above will still try to display an image, I could suggest an approach where you add a default image (like NoImage template) or set the control visibility to false if the value is null:

<telerik:RadBinaryImage runat="server" Visible='<%# !(Eval("BinaryImage") is DBNull)  %>' ID="RadBinaryImage1" DataValue='<%#  Eval("BinaryImage") is DBNull ? new byte[0] : Eval("BinaryImage")   %>' />

Hope this helps.


Regards,
Konstantin Dikov
Telerik

 

 

[Jon]

Hi Konstantin,

Of course, obvious now!  Thanks for that.  

The page looks superb now - a very useful addition :)

Best Regards

Jon