Hi:

I am building a program that uses a very simple plugin system. This is the code I'm using to load the possible plugins:

  public interface IPlugin
  {
    string Name { get; }
    string Description { get; }
    bool Execute(System.Windows.Forms.IWin32Window parent);
  }


  private void loadPlugins()
  {
    int idx = 0;
    string[] pluginFolders = getPluginFolders();
    Array.ForEach(pluginFolders, folder =>
    {
      string[] pluginFiles = getPluginFiles(folder);
      Array.ForEach(pluginFiles, file =>
      {
        try
        {
          System.Reflection.Assembly assembly = System.Reflection.Assembly.LoadFile(file);
          Array.ForEach(assembly.GetTypes(), type =>
          {
            if(type.GetInterface("PluginExecutor.IPlugin") != null)
            {
              IPlugin plugin = assembly.CreateInstance(type.ToString()) as IPlugin;
              if(plugin != null)
                lista.Add(new PluginItem(plugin.Name, plugin.Description, file, plugin));
            }
          });
        }
        catch(Exception) { }
      });
    });
  }

When the user selects a particular plugin from the list, I launch the plugin's Execute method. So far, so good! As you can see the plugins are loaded from a folder, and within the folder are several dll's that are needed but the plugin. My problem is that I can't get the plugin to 'see' the dlls, it just searches the launching applications startup folder, but not the folder where the plugin was loaded from.

I have tried several methods: 1. Changing the Current Directory to the plugins folder. 2. Using an inter-op call to SetDllDirectory 3. Adding an entry in the registry to point to a folder where I want it to look (see code below)

None of these methods work. What am I missing? As I load the dll plugin dynamically, it does not seem to obey any of the above mentioned methods. What else can I try?

Regards, MartinH.

//HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths
Microsoft.Win32.RegistryKey appPaths = Microsoft.Win32.Registry.LocalMachine.CreateSubKey(
  string.Format(
    @"SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\{0}",
     System.IO.Path.GetFileName(Application.ExecutablePath)),
  Microsoft.Win32.RegistryKeyPermissionCheck.ReadWriteSubTree);
appPaths.SetValue(string.Empty, Application.ExecutablePath);
object path = appPaths.GetValue("Path");
if(path == null)
  appPaths.SetValue("Path", System.IO.Path.GetDirectoryName(pluginItem.FileName));
else
{
  string strPath = string.Format("{0};{1}", path, System.IO.Path.GetDirectoryName(pluginItem.FileName));
  appPaths.SetValue("Path", strPath);
}
appPaths.Flush();