WebRequest.Http.Post (How does this work?)

[shanekahkola]

I am struggling with the process of using an EXE app to access an XML source across the web. A game I play online offers the ability to access character information, item databases, etc. by using an online API. To my knowledge, here is how it works:

The following URL should return an XML file that lists all of the characters on my account:
http://api.eve-online.com/account/Characters.xml.aspx?userID=5050156&apiKey=13DC16F65B424DC4A9479C69A2DA9C1613A1D36EAA1F49A0B93380FAC6F55C69

<?xml version="1.0" encoding="UTF-8" ?>
- <eveapi version="2">
<currentTime>2009-05-20 13:41:49</currentTime>
- <result>
- <rowset name="characters" key="characterID" columns="name,characterID,corporationName,corporationID">
<row name="G1ggler" characterID="165109553" corporationName="University of Caille" corporationID="1000115" />
</rowset>
</result>
<cachedUntil>2009-05-20 14:41:49</cachedUntil>
</eveapi>

Here is what I would like to do. I want to be able to receive that XML file and parse it into fields on a form. This is not ASP.NET, this is an executable with VB code pages. I have a form that requests the userID (7-digit number) and the apiKey (encrypted hash key). Here is my source code:

Dim rPost As WebRequest = WebRequest.Create("http://api.eve-online.com/account/Characters.xml.aspx")
Dim sData As String = "userID=" & txUserID.Text & "&apiKey=" & txLimitedAPI.Text
rPost.Method = WebRequestMethods.Http.Post
Dim rsGet As WebResponse = rPost.GetResponse
'rsGet = rPost.GetResponse
Dim sr As New StreamReader(rsGet.GetResponseStream(), Encoding.ASCII)
MsgBox("xml data", MsgBoxStyle.Information, sr.ReadToEnd)

When I execute the code, I get the following error:

The remote server returned an error: (411) Length Required.

The stack trace for the error is:

" at System.Net.HttpWebRequest.GetResponse()
at EveConnect.fNewProfile.bContinue_Click(Object sender, EventArgs e) in C:\Binaries\EXE.NET\EveConnect\EveConnect\fNewProfile.vb:line 13
at System.Windows.Forms.Control.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ButtonBase.WndProc(Message& m)
at System.Windows.Forms.Button.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.Run(ApplicationContext context)
at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun()
at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel()
at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine)
at EveConnect.My.MyApplication.Main(String[] Args) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 81
at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()"

I have created an account that will allow you to see what is supposed to happen. Here is the userID and the apiKey:

userID: 5050156
apiKey: 13DC16F65B424DC4A9479C69A2DA9C1613A1D36EAA1F49A0B93380FAC6F55C69

My guess is that I'm just not using the WebRequest.Http.Post properly, but Microsoft's documentation doesn't cover this very well.

Any help would be greatly appreciated.

 

[PlausiblyDamp]

Try changing it to

rPost.Method = WebRequestMethods.Http.Get

 

[shanekahkola]

rPost.Method = WebRequestMethods.Http.Get

You rock! Thank you for the advice - it worked beautifully. I'm sure I'll have questions down the road, but that suits my needs.

I hope I will be able to actually contribute as I get to know the .NET platform.

Thanks again.

 

[joe_pool_is]

I just wanted to say that you did an exellent job of describing your problem and providing visual aids. Wonderful job!