Steps to create Custom field type with visual studio 2010
1) Create new project select "Empty SharePoint project"
3) Select deploy solution as a farm solution.
7) open the fldtypes_CustomFieldTraining.xml file and enter the below node.
<!-- This file ensures that your SPField class is displayed in the list of available field types -->
FieldTypes>
<FieldType>
<Field Name="TypeName">TrainingCode</Field>
<Field Name="ParentType">Text</Field>
<Field Name="TypeDisplayName">Training Code</Field>
<Field Name="TypeShortDescription">Training Code</Field>
<Field Name="UserCreatable">TRUE</Field>
<Field Name="FieldTypeClass">CustomFieldType.Training_CustomFieldType, $SharePoint.Project.AssemblyFullName$</Field>
</FieldType>
</FieldTypes>
8) Enter a class file and give the name : Training_CustomFieldType.cs
Please check the name correctly because this is used in xml file as FieldTypeClass.
9) put the below lines in the CS file.
using System;
using System.Collections.Generic;
using System.Linq;using System.Text;
using Microsoft.SharePoint;
namespace CustomFieldType
{
/// <summary>/// When a user creates a new column in a List or Content Type, they see a list of /// Field Types, such as "Single Line of Text" and "Date and Time". By creating your/// own Field Type, you can extend this list. You can also include your own logic in /// the new Field Type, such as custom code to set the default value or validate user/// input. This code example shows how to create a custom Field Type/// </summary>/// <remarks>/// To create a custom field type, create an empty SharePoint project and then add a /// new class. The new class should inherit from a SPField class. In this case, the /// field stores strings, so we inherit from SPFieldText. You must also create a /// fldtypes*.xml file and deploy it to TEMPLATES\XML in the 14 hive. class Training_CustomFieldType:SPFieldText{#region Constructors
//You must create both these constructors, passing the parameters to the base classpublic Training_CustomFieldType(SPFieldCollection fields, string fName):
base(fields, fName){
}
public Training_CustomFieldType(SPFieldCollection fields, string tName, string dName):
base(fields, tName, dName){
}
#endregion//Override this property to formulate a default value. public override string DefaultValue{
get{return "CP0001";}
}
//Override this method to validate string data.public override string GetValidatedString(object value){
//Check that it starts with CP for "Training Code"if (!value.ToString().StartsWith("MS")){
//When you throw an SPFieldValidationException users see red text in the UIthrow new SPFieldValidationException("Training code must start with 'MS'");}
//Check that it's 6 characters longif (value.ToString().Length != 6){
throw new SPFieldValidationException("Training code must be 6 characters long");}
//Always convert to uppercase before writing to Content DB.return value.ToString().ToUpper();}
}
}
10) Deploy the solution and check the custom field while creating column.
http://msdn.microsoft.com/en-us/library/vstudio/ee361616.aspx
