Creating a new folder in a SharePoint library using C# Windows Application.

Question

I have tried to create a folder within a SharePoint document library. The coding is as follows.
Text Box Name: txtNewFolderName
Button Name : btnCreateNewFolder
private void btnCreateNewFolder_Click(object sender, EventArgs e)
//String parameters for site URL and site name
const string siteUrl = "http://thekingsbury/";
const string siteName = "/SiteDirectory/thekingsbury/";
//Freeze UI
Cursor = Cursors.WaitCursor;
btnCreateNewFolder.Enabled = false;
//Use SPSite constructor to assign site collection based on top-level URL
SPSite siteCollection = new SPSite(siteUrl);
//Assign target site (SPWeb instance) based on site name
SPWeb site = siteCollection.AllWebs[siteName];
//Create an instance of SPDocumentLibrary based on the named doc library list
SPDocumentLibrary docLibrary = (SPDocumentLibrary)site.Lists["Test Library"];
//Create instance of SPFolderCollection and add a named folder based on forms input,
//then update library to reflect added folder
SPFolderCollection myFolders = site.Folders;
myFolders.Add("http://thekingsbury/Test%20Library/" + txtNewFolderName.Text + "/");
docLibrary.Update();
//UI clean-up
Cursor = Cursors.Default;
btnCreateNewFolder.Enabled = true;
Site URL :
http://thekingsbury/
Site Name: thekingsbury
Document Library  : Test Library
My problem is when I click the button it gives an error as the following.
The Web application at http://thekingsbury/ could not be found.
Verify that you have typed the URL correctly.
If the URL should be serving existing content, the system administrator may need to add a new request URL mapping to the intended application.
The error shows at the following statement.
"SPSite siteCollection = new SPSite(siteUrl);"
I created both Windows & Web solutions and the result was the same.
Note: I have add the reference to the SharePoint using the Microsoft.SharePoint.dll file. And used the "using Microsoft.SharePoint;" statement.
Please can someone help me on this matter.It's a real paint to me.

Answer 1

The complete solution using an InfoPath 2010 form is as the below.
using Microsoft.Office.InfoPath;
using System;
using System.Xml;
using System.Xml.XPath;
using Microsoft.SharePoint;
using Microsoft.SharePoint.Client;
using Microsoft.SharePoint.Linq;
namespace Create_Folder_In_SharePoint_Library
public partial class FormCode
public void InternalStartup()
((ButtonEvent)EventManager.ControlEvents["btnCreateFolder"]).Clicked += new ClickedEventHandler(btnCreateFolder_Clicked);
public void btnCreateFolder_Clicked(object sender, ClickedEventArgs e)
SPSite mySite = new SPSite("Http://thekingsbury/");
SPWeb myWeb = mySite.OpenWeb();
//Code to retreive the new library.
XPathNavigator xLibraryName = MainDataSource.CreateNavigator();
String NewLibraryName = xLibraryName.SelectSingleNode("/my:myFields/my:LibraryName", NamespaceManager).Value;
//Code to retreive the library description.
XPathNavigator xLibraryDesc = MainDataSource.CreateNavigator();
String NewLibDesc = xLibraryDesc.SelectSingleNode("/my:myFields/my:LibraryDescription", NamespaceManager).Value;
//Code to retreive the new folder name.
XPathNavigator xFolderName = MainDataSource.CreateNavigator();
String NewFolderName = xFolderName.SelectSingleNode("/my:myFields/my:FolderName", NamespaceManager).Value;
//Creating the new library.
myWeb.Lists.Add(NewLibraryName, NewLibDesc, SPListTemplateType.DocumentLibrary);
myWeb.Update();
//Creating the new folder within the new library.
SPDocumentLibrary newDocLibrary = (SPDocumentLibrary)myWeb.Lists[NewLibraryName];
SPFolderCollection newFolders = myWeb.Folders;
newFolders.Add("http://thekingsbury/" + NewLibraryName + "/" + NewFolderName + "/");
newDocLibrary.Update();
I think everyone can use this.
 When you are generating a folder always try to avoid reserved characters  : ; # $ % ^ a and suchlike.