Make the following changes and additions to your applications:

• Remove RIO components from your applications. They will no longer work in the .NET Framework. Before deleting any components, save property information for the components, such as URLs.
• Remove Delphi 7 SOAP units from the uses clause and remove the uses reference to the Delphi 7 WSDL Importer-generated Interface proxy unit.
• Add a web reference by choosing the Add Web Reference command from the context menu of the Project Manager.

The following notes address discrete issues that you may encounter when porting web service client applications.

Delphi 7 and the .NET SOAP implementations differ slightly. You need to set certain options on the server (TSOAPDomConv.Options property) to succeed in getting multiple clients to work. Set the following options to ensure that both client applications can process the SOAP packages and can transfer the correct encoding:

[soTryAllSchema, soRootRefNodesToBody, soUTF8InHeader, soUTF8EncodeXML]

The following table shows the corresponding exceptions between Delphi 7 and the .NET Framework.

In Delphi 7, the ERemotableException.FaultCode property returns a qualified name, such as SOAP-ENV:Client.Login. You must then extract the code using the ExtractLocalName function. The .NET Framework SoapException class provides the SoapException.Code.Name property directly.

In Delphi 7, the THTTPRIO component provides OnBeforeExecute and OnAfterExecute events, which allow you to monitor requests and responses. You can implement similar functionality using the .NET Framework SoapExtension class. The following is part of an example that implements this functionality. You can find the full example on Borland's CodeCentral. The link is included in the link list at the end of this topic.

uses
  System.Xml, System.Web.Services, System.Web.Services.Protocols, System.IO;

type
  TSoapMessageEvent = procedure (Sender: TObject; const Xml: string) of object;

  TSoapMonitor = class(TObject)
  private
    FOnRequest: TSoapMessageEvent;
    FOnResponse: TSoapMessageEvent;
  protected
    procedure DoRequest(const Xml: string);
    procedure DoResponse(const Xml: string);
  public
    class function FormatXmlData(const Xml: string): string; static;
    property OnRequest: TSoapMessageEvent add FOnRequest remove FOnRequest;
    property OnResponse: TSoapMessageEvent add FOnResponse remove FOnResponse;
  end;
    .
    .
    .
{ TSoapMonitor }

procedure TSoapMonitor.DoRequest(const Xml: string);
begin
  if Assigned(FOnRequest) then
    FOnRequest(Self, Xml);
end;

procedure TSoapMonitor.DoResponse(const Xml: string);
begin
  if Assigned(FOnResponse) then
    FOnResponse(Self, Xml);
end;

class function TSoapMonitor.FormatXmlData(const Xml: string): string;
var
  Doc: XmlDocument;
  Sw: StringWriter;
  Xw: XmlTextWriter;
begin
  Doc := XmlDocument.Create;
  Doc.LoadXml(Xml);
  Sw := StringWriter.Create;
  Xw := XmlTextWriter.Create(sw);
  Xw.Formatting := Formatting.Indented;
  Xw.Indentation := 2;
  Xw.IndentChar := ' ';
  doc.Save(xw);
    Result := sw.ToString;
  Xw.Close;
  Sw.Close;
end;

In Delphi 7, you are required to send the header before every method call. The header object is freed after the call. In the .NET Framework, the header class persists after calling a method, until new is assigned, or until the header class is cleared by assigning nil.

The .NET Framework does not support MIME attachments. Delphi 7 SOAP does not support DIME attachments.

ASP.NET Web Services Overview 

Porting a Delphi for Win32 Web Service Client Application to Delphi for .NET 

CodeCentral Monitoring SOAP Packets Example