I want to add result of sql query to dropdownlist items

 

 have tried this :

 

RadListDataItem dataItem = new RadListDataItem();
                            dataItem.Text = (read1["size"].ToString());
                            this.radDropDownList2.Items.Add(dataItem);

Hello, Ahmed, 

Thank you for writing.  

In order to populate RadDropDownList with data you have two approaches:

1. Add the items programmatically to the Items collection: https://docs.telerik.com/devtools/winforms/dropdown-listcontrol-and-checkeddropdownlist/dropdownlist/populating-with-data/adding-items-programmatically

2. Bind RadDropDownList: https://docs.telerik.com/devtools/winforms/dropdown-listcontrol-and-checkeddropdownlist/dropdownlist/populating-with-data/data-binding

You can also refer to our Demo application >> DropDown & List >> DropDownList >> DataBinding example. The Demo application can be found in the installation folder of the suite. 
  
I hope this information helps. Should you have further questions I would be glad to help. 
 
 Regards,
Dess
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