SharePoint custom form - sharepoint

Question

I am looking to create a page with a single form on it that does the following:
Contact a webservice with input from the form.
Perform an action (programmed using C#) depending on the result of the webservice call.
Since I am not interacting with any lists or similar on the SharePoint site, I was thinking a WebPart would be the simplest way to add the form and catch the submit-event, but I am not sure if this is the best practice or an easier/better way exists.
I also need to restrict access to the form to a specific usergroup.
Thanks in advance!

Answer 1

A new SharePoint Web Part is probably the most common way to provide this solution in SharePoint and fits your requirements well. Though your solution doesn't call for it, you do have access to the lists from custom web part code.
If you are using SharePoint 2007, Visual Studio Extensions provide the Microsoft supported way to create one easily. It's much easier with Visual Studio 2010 and SharePoint 2010.
Some other options would be an InfoPath Form with custom code or a custom application page with code behind. The benefit of the web part is that it works with all versions of SharePoint and can be added to any web part page on the site and customized by users. Also, the application page may not pick up the master page if you are on SharePoint 2007.

Answer 2

Use WebDAV to upload an ASPX page to a site in SharePoint. Then upload your assembly to each SharePoint server, the bin folder of your application is preferred, or add it to the GAC.
Your ASPX page might look like this:
<%# Page Language="C#" masterpagefile="~masterurl/custom.master" inherits="MyAssembly, MyClass, Version=1.0.0.0, Culture=neutral, PublicKeyToken=c48b11b32c9eb4a7" %>
<asp:Content runat="server" ContentPlaceholderID="PlaceHolderPageTitle">My Title</asp:Content>
<asp:Content runat="server" ContentPlaceholderID="PlaceHolderPageTitleInTitleArea">My Page</asp:Content>
<asp:Content runat="server" ContentPlaceholderID="PlaceHolderMain">
<asp:Button runat="server" ID="ButtonClickMe" Text="Click Me!" />
</asp:Content>
Then your assembly might look something like this:
public class MyClass : Microsoft.SharePoint.WebPartPages.WebPartPage
{
protected global::System.Web.UI.WebControls.Button ButtonClickMe;
protected override void OnLoad(EventArgs e)
{
base.OnLoad( e );
ButtonClickMe.Click += new EventHandler( ButtonClickMe_Click );
}
void ButtonClickMe_Click(object sender, EventArgs e)
{
if (!Page.IsValid)
return;
// Do stuff here
}
}
You won't be able to edit the permissions of the ASPX page directly, but you can manipulate the permissions of the site it is in (thus, restrict the site to only the usergroup which you want to access the form).