This part of the article is going to be the last of the series. In the last part I introduced you to what the .NET Assemblies are and for what reasons are they used? You also were informed about the advantages of using the .NET Assemblies as compared to the other scripting techniques that we have available in the ASP .NET.
Before implementing an assembly I would like to add, that we implement many pre-built assemblies while we are working on ASP .NET based applications. For example; the System namespace and other namespaces like it i.e. System.Data, System.Web are also pre-built assemblies that have been provided in the .NET framwork to us by Microsoft. In addition to this they have also provided us the capability of making our own assemblies. As compared to the classic ASP making components in form of assemblies in ASP .NET is much more easier and flexible.
Now let's go ahead with creating our first component. This is going to be a simple component that would just provide us with a few options to display a message on the screen. Write the following code in Notepad or any other editor that you have.
Public Class DisplayConsole
Public Function Welcome() As String
Return "Welcome to your first component!"
Public Function Output(strParam As String) As String
Save this file by the name "hrmDisplay.vb".
Now for the process of converting this file into a compiled DLL file, we require to make a batch file. Again open the Notepad and add the following to it. Save the following file by name "MakeComponent.bat"
vbc /t:library /out:%outdir% %indir% /r:%assemblies%
Before running the file you require to create a directory by the name of bin. Create a directory in your current directory by name of bin and then run the file. Checkout the bin directory your DLL file would be placed there after its creation.
Before using the component we require to do one more thing! and that is to make a web.config file. Web.config is an XML based file that specifies important configuration for an ASP .NET application. Again open up the Notepad and write the following code.
Save this file as "web.config". The reason that we made the bin directory and then placed the DLL file within it was that the web.config would always search for the file in the bin directory, not only this assembly, but other user defined and third party assemblies also require there references to be added into the web.config.
Now we are ready to use our component within our ASP .NET page. Open up Notepad or any other editor and add the following code into the file and save it as "Test.aspx".
<%@ Import Namespace = "HRM.Display" %>
<%@ Page Language = "VB" %>