[Closed] .NET: how to unload assembly ?

Yea, It is bit wired…please try the following way, I have used Maxscript to make it bit easy to understand for MaxScripters as my level best.

   ---here I have one visual studio C# class lib project with this code
   ---what I'm compiling as MYLib.dll
   
   /* using System;
   * using System.Windows.Forms;
   * namespace MYLib
   * {
   *	 
   *	 /// <summary>
   *	 /// First version
   *	 /// </summary>
   *	 //public class MyClass
   *	 //{
   *	 //	public void Call()
   *	 //	{
   *	 //		MessageBox.Show("Say First");
   *	 //	}
   *	 //}
   * 
   *	 /// <summary>
   *	 /// Second version
   *	 /// </summary>
   *	 public class MyClass
   *	 {
   *		 public void Call()
   *		 {
   *			 MessageBox.Show("Say Second");
   *		 }
   *	 }
   * }
   */
   
   ------------Now in Maxscript----------------------------
   
   ---Create dotnet class to use some useful static functions
   AppDomain = dotNetClass "System.AppDomain"
   Assembly = dotNetClass "System.Reflection.Assembly"
   AssemblyName = dotNetClass "System.Reflection.AssemblyName"
   
   ---set the shadow copy so actually original assembly file can be overriten...SetShadowCopyFiles is obsoluted according to MSDN
   ---but that is the only way to enable ShadowCopy option for current AppDomain. Because through Maxscript
   ---creation of new appdomain is not possible so we have to use current AppDoamin and for 3dsMax2009 ShadowCopy for current Appdomain is false bydefault
   --- whatever the dir we use with SetShadowCopyPath, all assembly loaded later from this directory automatically will be shadow copied by .net runtime
   ---I'm for demonstartion using "C:\Release" but you can use directly use yourVCSharpProject/Bin/Release or Debug folder
   ---make sure everytime you have differnt version number, In case of Visual Studio 2008 C# project version settings
   ---under project settings -> Application-->Assembly Information or you can change AssemblyInfo.cs file of your project manually
   ----or the addin I have specified for visual studio to autoincrement it you can use  http://www.codeplex.com/autobuildversion 
   
   ---using default cache path ensure delete of shadow copy files will be  handle by runtime automatically
   ---if you use your own cache path using AppDomain.CurrentDomain.SetCachePath then you have delete them manually
   ---So I'm not using that
   
   AppDomain.CurrentDomain.SetShadowCopyPath (@"C:\Release\")
   AppDomain.CurrentDomain.SetShadowCopyFiles()
   
   
   ----load the first version...again don't forget to use different version for every compile in visual studio
   ----AssemblyName.GetAssemblyName using this method we can query to the dll what the version number we have setted in visual studio
   assemName = AssemblyName.GetAssemblyName(@"C:\Release\MYLib1.dll")
   print assemName.FullName
   ---result "MYLib, Version=1.0.0.0, Culture=neutral, PublicKeyToken=d8101bd49700bbd5"
   
   ----Now load it using assembly name, don't use LoadFromFile
   assem = Assembly.Load assemName
   print assem.Location
   ---will print the temp file path runtime used for shadow copy  somthing like "\Application Data\assembly\dl3\OAV6J36X.Q9J\1Z7DWQ44.552\0f496cae\004a3872_967cc901\MYLib1.dll"
   
   ---use this way to create object of sepcific version instead of (dotNetObject "MYLib.MyClass")
   myObj = assem.CreateInstance "MYLib.MyClass" ---create object of first version of MYLib.MyClass
   myObj.Call() --- call the first version of the method
   
   assemName = AssemblyName.GetAssemblyName(@"C:\Release\MYLib2.dll")
   print assemName.FullName
   ---result "MYLib, Version=1.1.0.0, Culture=neutral, PublicKeyToken=d8101bd49700bbd5"
   
   assem = Assembly.Load assemName
   print assem.Location
   --- show the temp file path runtime used for shadow copy  somthing like "\Application Data\assembly\dl3\OAV6J36X.Q9J\1Z7DWQ44.552\3da67b63\00d97aa5_967cc901\MYLib2.dll"
   
   myObj = assem.CreateInstance "MYLib.MyClass" ---create object of second version of MYLib.MyClass
   myObj.Call()--- call the second version of the method
   
   

Thankyou for your trouble describing this, susanta. I hadn’t understood the documentation, and was trying to load the wrong way ( giving no access to the version No. ). This has saved a pile of trial and error, discovering the behaviour of GetAssemblyName, etc.

here’s a thing – can you dynamically compile dlls that have referenced assemblies? this has worked fine with anything within the system namespace, but when i have tried adding code containing things like System.drawing.image im getting errors. In VS this is done for you by adding the assembly as a reference and then putting imports or using before the class definition. However i wasnt sure how to do this manually.

Hey Dr,

ah, Thanks for that, I’ll look into it and report back. cheers!