Adding a DataSource property to a Custom Control

To add a DataSource property to a custom control as shown in the following image, perform these steps:

1. Add the Prop ID sections to your Definition.XML file.
   The XML shown here is an example of a full definition file, and yours may look different.
   
   <?xml version="1.0" encoding="utf-8" ?>
   <ControlType>
       <FullName>CustomControlDataSourceExample.DataSourceExample, CustomControlDataSourceExample</FullName>
       <Category>Listing</Category>
       <Group>Custom</Group>
       <Name>DataSrcEx</Name>
     <DisplayName>DataSourceEx</DisplayName>
       <Properties>
         <Prop ID="DataSourceType" friendlyname="Type" type="complex" serverControlType="property" category="Data Source" InitializeServerControl="initializeAssociationPropertyConfig" ClearServerControl="clearComplexPropertyConfig" ServerControl="SourceCode.Forms.Controls.Web.PropertyConfiguration.AssociationPropertyConfig, SourceCode.Forms.Controls.Web" />
         <Prop ID="FixedListItems" friendlyname="Items" type="string" serverControlType="property" category="Data Source" ReadOnly="true" />
         <Prop ID="AssociationSO" friendlyname="SmartObject" type="string" serverControlType="smartobject" category="Data Source" ReadOnly="true" />
         <Prop ID="AssociationMethod" friendlyname="Method" type="string" serverControlType="listmethod" category="Data Source" ReadOnly="true" />
         <Prop ID="ValueProperty" friendlyname="Value" type="string" serverControlType="property" category="Data Source" ReadOnly="true" />
         <Prop ID="DisplayTemplate" friendlyname="Display" type="string" serverControlType="property" category="Data Source" ReadOnly="true" />
       </Properties>
   </ControlType>
   
2. Add the get and set information shown here to your C# code file:
   
   //Link to the definition file
   [ControlTypeDefinition("CustomControlDataSourceExample.Definition.xml")]
   public class DataSourceExample: BaseControl {
    // add the following lines to your C# code in the relavant place
    public string DataSourceType {
     get {
      return this.Attributes["DataSourceType"];
     }
     set {
      this.Attributes["DataSourceType"] = value;
     }
    }
    protected override void RenderContents(System.Web.UI.HtmlTextWriter writer) {
     writer.Write(" <b>Basic DataSource Control</b>");
    }
   }