Assign SharePoint Item Picker control to External Data / BCS Column

Recently, I need to create visual webpart to display the item picker control like External Data / BCS column in list new or edit form.
Let’s go straight on how to assign the item picker as External Data column.

• 1. Add Item Picker control in ascx file and initialize OnLoad attributes.

<SharePoint:ItemPicker ID="myPicker" runat="server" OnLoad="myPicker_Load" CssClass="ms-input" />

2. In ascx.cs file and OnLoad item picker events.

protected void myPicker_Load(object sender, EventArgs e)

{

 try

 {

  // Set extended data

  myPicker.ExtendedData = GetExtendedData("SystemInstanceName", "EntityName", "PrimaryColumnName", "EntityNamespace");

  // Set other properties

  myPicker.AllowTypeIn = true;

  myPicker.AllowEmpty = false;

  myPicker.AutoPostBack = false;

  myPicker.MultiSelect = false;

 }

 catch (Exception ex)

 {

  // Your error handler

 }

}

private Microsoft.SharePoint.WebControls.ItemPickerExtendedData GetExtendedData(string systemInstanceName, string entityname, string primaryColumnName, string entityNameSpace)

{

 ItemPickerExtendedData extendedData = null;

 try

 {

  // Associate Network Affiliate Item Picker

  extendedData = new ItemPickerExtendedData();

  extendedData.SystemInstanceName = systemInstanceName;

  extendedData.EntityName = entityname;

  extendedData.PrimaryColumnName = primaryColumnName;

  extendedData.EntityNamespace = entityNameSpace;

 }

 catch (Exception ex)

 {

  // Your error handler

 }

 return extendedData;

}




The next question is, how are we going to get these values “SystemInstanceName”, “EntityName”, “PrimaryColumnName”, “EntityNamespace” ?

• 1. Create SharePoint list “MyList”, add new External Data column “MyField” to the list.
• 2. Create simple SharePoint console application project and populate Main method like below.

private static void Main(string[] args)

{

 try

 {

  using (SPSite site = new SPSite("YourSiteURL"))

  {

   using (SPWeb web = site.OpenWeb("YourWeb"))

   {

    SPList listResult = web.Lists.TryGetList("MyList");

    if (listResult == null)

     return null;

    foreach (SPField eachField in listResult.Fields)

    {

     if (eachField != null && eachField.Title == "MyField" && eachField is SPBusinessDataField) vbc














































































































































































































































































































































































































































     {

      //Read in the field schema so that we can obtain extra values to perform a query against the BCS.

      XmlDocument xmlData = new XmlDocument();

      xmlData.LoadXml(eachField.SchemaXml);

      //This get all attributes required for External Data column

      string systemInstanceName = xmlData.FirstChild.Attributes["SystemInstance"].Value;

      string primaryColumnName = xmlData.FirstChild.Attributes["BdcField"].Value;

      string entityNameSpace = xmlData.FirstChild.Attributes["EntityNamespace"].Value;

      string entityname = xmlData.FirstChild.Attributes["EntityName"].Value;

      Console.WriteLine(string.Format("SystemInstanceName:{0}; PrimaryColumnName:{1}; EntityNamespace:{2}; EntityName:{3}", systemInstanceName, primaryColumnName, entityNameSpace, entityname));

     }

    }

   }

  }

 }

 catch (Exception ex)

 {

  Console.WriteLine("ERROR: " + ex.Message);

 }

 Console.ReadLine();

}