Creating a Data Processing Extension Library
Each Reporting Services data processing extension you create should be assigned to a unique namespace and built into a library or assembly file. The exact name of the namespace is not important, but it must be unique and not shared with any other extension. Microsoft uses the namespace Microsoft.ReportingServices.DataProcessing for the data processing extensions that ship with Reporting Services. You should create your own unique namespaces for your company's data processing extensions.
The following example shows the code to begin a Reporting Services data processing extension, which uses the namespaces that contain the data processing interfaces and any utility classes.
When compiling a Reporting Services data processing extension, you must supply to the compiler a reference to Microsoft.ReportingServices.Interfaces.dll, because the data processing extension interfaces are contained there. The Microsoft.ReportingServices.DataProcessing namespace is needed to implement the data processing extension interfaces, and the Microsoft.ReportingServices.Interfaces namespace is needed to implement the IExtension interface. For example, if all the files containing the code to implement a Reporting Services data processing extension written in C# were in a single directory with the extension .cs, the following command would be issued from that directory to compile the files stored in CompanyName.ExtensionName.dll.
csc /t:library /out:CompanyName.ExtensionName.dll *.cs /r:System.dll /r:Microsoft.ReportingServices.Interfaces.dll
The following code example shows the command that would be used for Microsoft Visual Basic files with the extension .vb.
vbc /t:library /out:CompanyName.ExtensionName.dll *.vb /r:System.dll /r:Microsoft.ReportingServices.Interfaces.dll
You can also design, develop, and build your data processing extension using Visual Studio. For more information about developing assemblies in Visual Studio, see your Visual Studio documentation.