Problem with Tag and Content

[Martin]

Hello,

I would like to use a Combobox in my GridView.

In-Code I do the following:

 

RadComboBoxItem boxitem = new RadComboBoxItem();
boxitem.Tag = item.ID;
boxitem.Content = item.Name;
comboboxlist.Add(boxitem);

GridViewComboBoxColumn column = new GridViewComboBoxColumn();
System.Windows.Data.Binding bind = new System.Windows.Data.Binding("Name");
bind.Mode = System.Windows.Data.BindingMode.TwoWay;
column.UniqueName = "Name";
column.DisplayMemberPath = "Content";
column.SelectedValueMemberPath = "Tag";
column.ItemsSource = comboboxlist;
column.DataMemberBinding = bind;
radGridView1.Columns.Add(column);
radGridView1.ItemsSource = Sourcelist;

 

 

 

The Items are displayed according to "Content". But as soon as I select an item, the value is not shown in the ComboBox, it simply disappears, but stores the ID in the Variable. But when I set DisplayMemberPath to "Tag", it does not make any difference, the Content is shown.

How can I show "Content" and register "Tag" and then, when the "Tag" is pulled out the database again show the content?

Thank you

 

 

[Maya]

Hi Martin,

The properties of the GridViewComboBoxColumn should be set as follows:
 - DataMemberBinding - binding to a property from the ItemsSource of the grid - for example - int CountryID;
 - SelectedValueMemberPath - set to a property from the source of the column - for exampel - int ID
 -> both properties should be of the same type (in the case above - "int"). This is the mechanism by which the selected value from the combo box is transfered to the value of the underlaying data item.
 - DisplayMemberPath - set to a property from the source of the column. It defines the value that will be displayed to the end-user.

Based on the above, may you try the following - bind your column to a property from the source of the grid that will correspond to the one defined in the SelectedValueMemberPath ? Furthermore, may you try to set the SelectedValueMemberPath directly to the property  from the business object of the GridViewComboBoxColumn not the the "Tag" ?
 
Regards,
Maya
the Telerik team

[Martin]

Hello,

yes thats clear, but I don't understand your answer.My problem is the following one:

I have a Text in a ComboBox the user should see. But that text should not be written into the Binding Object, it is a Guid which should be written there. How can I archieve that?
I tried it with the following code

RadComboBoxItem boxitem = new RadComboBoxItem();
 ContentControl cont = new ContentControl();
 cont.Tag=item.ID;
 cont.Content=item.Name;
 boxitem.Tag = item.ID;
 boxitem.Content = cont;
 comboboxlist.Add(boxitem);

but that does only work when I select one item. After selecting the second item I always get the famous "catch-all-error"
"Element is already the cild of another element".

How can I archieve this functionality I would like?

Thanks,

Martin

[Maya]

Hello Martin,

Generally, the recommended approach is to expose a property for the GridViewComboBoxColumn. The idea behind is based on the fact that the virtualization is turned on by default. This means that the visual elements are recycled and reused. Consequently, the selected values will probably be not saved unless there is a property of the business object to bound to. 
May you provide more information about the reason not to expose a property to bound to ? 

All the best,
Maya
the Telerik team

[Martin]

Hi Maya,

thank you for your answer. Do you have an example how to archieve my goal?

Thanks,

Martin

[Maya]

Hi Martin,

You may take a look at our online documentation and demos both referring to the correct usage of GridViewComboBoxColumn.  

Greetings,
Maya
the Telerik team