IntroductionToday, in this article let's play around with one of the interesting and most useful concepts in SharePoint 2010.
Question: What is ContentType?  
In simple terms "Content types are reusable sets of columns create which can be used across multiple lists or libraries. They are considered to be a central component to manage metadata".
Step 1: Open SharePoint 2010 Central Administration and navigate to a specific site.
 
Step 2: Open up Visual Studio 2012 and try to "SharePoint Visual Web Part" project, as in:
 
![open-sharepoint2010-visual-webpart.jpg]()
 
 Step 3: Select "Deploy as a farm solution" as in the following and click the "Finish" button. 
 
![sharepoint-customization-wizard.jpg]()
 
 Step 4: The complete code of visualwebpart1usercontrol.ascx looks like this:
 
<%@ Assembly Name="$SharePoint.Project.AssemblyFullName$" %>
<%@ Assembly Name="Microsoft.Web.CommandUI, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%@ Register TagPrefix="SharePoint" Namespace="Microsoft.SharePoint.WebControls"
    Assembly="Microsoft.SharePoint, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%@ Register TagPrefix="Utilities" Namespace="Microsoft.SharePoint.Utilities" Assembly="Microsoft.SharePoint, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%@ Register TagPrefix="asp" Namespace="System.Web.UI" Assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" %>
<%@ Import Namespace="Microsoft.SharePoint" %>
<%@ Register TagPrefix="WebPartPages" Namespace="Microsoft.SharePoint.WebPartPages"
    Assembly="Microsoft.SharePoint, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%@  Control Language="C#" AutoEventWireup="true" CodeBehind="VisualWebPart1.ascx.cs"
    Inherits="DeleteFieldContentTypeApp.VisualWebPart1.VisualWebPart1" %>
<div>
    <table style="font-family: Verdana; text-align: center;">
        <tr>
            <td colspan="2">
                <asp:label id="Label1" runat="server" text="Delete Field - Content Type - SharePoint 2010 via Visual Studio 2012"
                    font-bold="true" forecolor="Maroon" font-size="Large"></asp:label>
            </td>
        </tr>
        <tr>
            <td>
                <asp:label id="Label2" runat="server" text="Please Enter ContentType Name:"></asp:label>
            </td>
            <td>
                <asp:textbox id="TextBox1" runat="server"></asp:textbox>
            </td>
        </tr>
        <tr>
            <td>
                <asp:label id="Label3" runat="server" text="Please Enter Field Name:"></asp:label>
            </td>
            <td>
                <asp:textbox id="TextBox2" runat="server"></asp:textbox>
            </td>
        </tr>
        <tr>
            <td colspan="2">
                <asp:button id="Button1" runat="server" text="Delete Field - SiteContentType " forecolor="Orange"
                    font-bold="true" backcolor="Black" onclick="Button1_Click" width="261px" />
            </td>
        </tr>
        <tr>
            <td colspan="2">
                <asp:label id="Label4" runat="server" font-bold="true"></asp:label>
            </td>
        </tr>
    </table>
</div>
 
Step 5: The complete code of visualwebpart1usercontrol.ascx.cs looks like this:
 
using Microsoft.SharePoint;
using System;
using System.ComponentModel;
using System.Web.UI.WebControls.WebParts;namespace DeleteFieldContentTypeApp.VisualWebPart1
{
    [ToolboxItemAttribute(false)]
    public partial class VisualWebPart1 : WebPart
    {
        // Uncomment the following SecurityPermission attribute only when doing Performance Profiling using
        // the Instrumentation method, and then remove the SecurityPermission attribute when the code is ready
        // for production. Because the SecurityPermission attribute bypasses the security check for callers of
        // your constructor, it's not recommended for production purposes.
        // [System.Security.Permissions.SecurityPermission(System.Security.Permissions.SecurityAction.Assert, UnmanagedCode = true)]
        public VisualWebPart1()
        {
        }
        protected override void OnInit(EventArgs e)
        {
            base.OnInit(e);InitializeControl();
        }
        protected void Page_Load(object sender, EventArgs e)
        {
            TextBox1.Focus();
        }
        protected void Button1_Click(object sender, EventArgs e)
            {
                if (string.IsNullOrEmpty(TextBox1.Text) || string.IsNullOrEmpty(TextBox2.Text))
                {
                    Label4.Text = "Please Enter Some Values";
                    Label4.ForeColor = System.Drawing.Color.Red;
                }
                else{SPContentTypeCollection contentCollection = SPContext.Current.Web.ContentTypes;
                    SPContentType contentType = contentCollection[TextBox1.Text];
                    contentType.FieldLinks.Delete(TextBox2.Text);
                    contentType.Update();
                    Label4.Text = TextBox2.Text + " - Field Deleted Successfully";
                    Label4.ForeColor = System.Drawing.Color.Green;
                    TextBox1.Text = string.Empty;
                    TextBox2.Text = string.Empty;
                }
        }
    }
}
 
Step 6: Deploy the solution file and add the new webpart to a SharePoint site.
 
Step 7: The output of the application looks like this
 :
![delete-field-content-type-sharepoint2010.jpg]()
 
 
Step 8: Content type exists output of the application looks like this:
 
![Content-type-exists-output-sharepoint2010.jpg]()
 
Step 9: Site content type field output of the application looks like this:
 
![Site-content-type-field-output-sharepoint2010.jpg]()
 
Step 10: Date entering output of the application looks like this:
 
![app-delete-field-content-type-sharepoint2010.jpg]()
 
 
Step 11: Field deleted output of the application looks like this:
 
![field-Site-content-type-output-sharepoint2010.jpg]()
I hope this article is useful for you.