Here is an annoying thing about CommandMethod attributes in AutoCAD .Net dlls: you can have two different commands that have the same name but refer to different .Net methods, for example consider the following code:
[CommandMethod("Test")]
public void SomeMethod()
{
// Implementation …
}
[CommandMethod("Test")]
public void SomeOtherMethod()
{
// Implementation …
}
What is going on if you try to netload a dll containing that code in AutoCAD? It will compile fine as there is no syntax error in the code, but you will get a frustrating error message in the command line:
Cannot load assembly. Error details: Autodesk.AutoCAD.Runtime.Exception: eDuplicateKey at Autodesk.AutoCAD.Runtime.CommandClass.AddCommand(ICommandLineCallable ca, MethodInfo mi) at Autodesk.AutoCAD.ApplicationServices.AutoCADApplicationHolder.Initialize(Assembly assembly) at Autodesk.AutoCAD.ApplicationServices.ExtensionLoader.ProcessAssembly(Assembly assembly)
There is no way to know which command name has caused that exception. Rather straightforward to fix it in that scenario, but in my case I work with a .Net dll that contains hundreds of commands split across dozen of files, so when I quickly cut and paste some code to test it, I can end up with duplicate commands which are hard to find.
A solution to that can be to use .Net reflection capabilities to find out the duplicates. This is what is doing the following piece of code: you need to run it from a separate .Net dll and load the dll that contains the duplicates using FindCmdDuplicates (path):
[CommandMethod("FindCmdDuplicates")]
public void FindCmdDuplicatesCmd()
{
string asmPath = SelectAssembly();
if (asmPath == null)
return;
FindCmdDuplicates(asmPath);
}
private string SelectAssembly()
{
System.Windows.Forms.OpenFileDialog dlg =
new System.Windows.Forms.OpenFileDialog();
dlg.Title = "Load Assembly File";
dlg.InitialDirectory = Environment.GetFolderPath(
Environment.SpecialFolder.Desktop);
dlg.Filter = ".Net Assembly (*.dll)|*.dll";
dlg.FilterIndex = 1;
dlg.RestoreDirectory = true;
while (dlg.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
try
{
AssemblyName asmName =
AssemblyName.GetAssemblyName(dlg.FileName);
return dlg.FileName;
}
catch (BadImageFormatException ex)
{
System.Windows.Forms.MessageBox.Show(
"Sorry the file is not a valid .Net assembly…",
"Invalid Assembly",
System.Windows.Forms.MessageBoxButtons.OK,
System.Windows.Forms.MessageBoxIcon.Error);
}
}
return null;
}
public void FindCmdDuplicates(string asmPath)
{
Dictionary<string, List<MethodInfo>> map =
new Dictionary<string, List<MethodInfo>>();
Assembly asm = Assembly.LoadFile(asmPath);
Type[] expTypes = asm.GetTypes();
foreach (Type type in expTypes)
{
MethodInfo[] methods = type.GetMethods();
foreach (MethodInfo method in methods)
{
CommandMethodAttribute attribute =
GetCommandMethodAttribute(method);
if (attribute == null)
continue;
if (!map.ContainsKey(attribute.GlobalName))
{
var methodInfo = new List<MethodInfo>();
map.Add(attribute.GlobalName, methodInfo);
}
map[attribute.GlobalName].Add(method);
}
}
Document doc = Application.DocumentManager.MdiActiveDocument;
Editor ed = doc.Editor;
foreach (var keyValuePair in map)
{
if
(keyValuePair.Value.Count > 1)
{
ed.WriteMessage(
"\nDuplicate Attribute: " + keyValuePair.Key);
foreach (var method in keyValuePair.Value)
{
ed.WriteMessage(
"\n – Method: " + method.Name);
}
}
}
}
public CommandMethodAttribute GetCommandMethodAttribute(
MethodInfo method)
{
object[] attributes = method.GetCustomAttributes(true);
foreach (object attribute in attributes)
{
if (attribute is CommandMethodAttribute)
{
return attribute as CommandMethodAttribute;
}
}
return null;
}
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