private void btnLoadPlugin_Click(object sender, EventArgs e)
{
if (openPluginFileDialog.ShowDialog() != DialogResult.OK)
{
return;
}
LoadPluginResult loadResult = PluginManager.LoadPlugin(openPluginFileDialog.FileName);
switch (loadResult)
{
case LoadPluginResult.Success:
PluginManager.LoadPluginsInfoToListBox(lbPlugins);
break;
case LoadPluginResult.Failed:
MessageBox.Show(Resources.FailedToLoadPlugin, string.Empty, MessageBoxButtons.OK, MessageBoxIcon.Error);
break;
case LoadPluginResult.AlreadyExists:
MessageBox.Show(Resources.PluginAlreadyExists, string.Empty, MessageBoxButtons.OK, MessageBoxIcon.Information);
break;
}
}
private static LoadPluginResult LoadPluginFromFolder(string pluginFolderPath, ICollection <string> installedPluginSystemNames)
{
Guard.ArgumentNotEmpty(() => pluginFolderPath);
var folder = new DirectoryInfo(pluginFolderPath);
if (!folder.Exists)
{
return(null);
}
var descriptionFile = new FileInfo(Path.Combine(pluginFolderPath, "Description.txt"));
if (!descriptionFile.Exists)
{
return(null);
}
// load descriptor file (Description.txt)
var descriptor = PluginFileParser.ParsePluginDescriptionFile(descriptionFile.FullName);
// some validation
if (descriptor.SystemName.IsEmpty())
{
throw new Exception("The plugin descriptor '{0}' does not define a plugin system name. Try assigning the plugin a unique name and recompile.".FormatInvariant(descriptionFile.FullName));
}
if (descriptor.PluginFileName.IsEmpty())
{
throw new Exception("The plugin descriptor '{0}' does not define a plugin assembly file name. Try assigning the plugin a file name and recompile.".FormatInvariant(descriptionFile.FullName));
}
var result = new LoadPluginResult
{
DescriptionFile = descriptionFile,
Descriptor = descriptor
};
//ensure that version of plugin is valid
if (!IsAssumedCompatible(descriptor))
{
result.IsIncompatible = true;
return(result);
}
if (_referencedPlugins.ContainsKey(descriptor.SystemName))
{
throw new Exception(string.Format("A plugin with system name '{0}' is already defined", descriptor.SystemName));
}
if (installedPluginSystemNames == null)
{
installedPluginSystemNames = PluginFileParser.ParseInstalledPluginsFile();
}
// set 'Installed' property
descriptor.Installed = installedPluginSystemNames.Contains(descriptor.SystemName);
try
{
// get list of all DLLs in plugin folders (not in 'bin' or '_Backup'!)
var pluginBinaries = descriptionFile.Directory.GetFiles("*.dll", SearchOption.AllDirectories)
// just make sure we're not registering shadow copied plugins
.Where(x => IsPackagePluginFolder(x.Directory))
.ToList();
// other plugin description info
var mainPluginFile = pluginBinaries.Where(x => x.Name.IsCaseInsensitiveEqual(descriptor.PluginFileName)).FirstOrDefault();
descriptor.OriginalAssemblyFile = mainPluginFile;
// shadow copy main plugin file
descriptor.ReferencedAssembly = Probe(mainPluginFile);
if (!descriptor.Installed)
{
_inactiveAssemblies.Add(descriptor.ReferencedAssembly);
}
// load all other referenced assemblies now
var otherAssemblies = from x in pluginBinaries
where !x.Name.IsCaseInsensitiveEqual(mainPluginFile.Name)
select x;
foreach (var assemblyFile in otherAssemblies)
{
if (!IsAlreadyLoaded(assemblyFile))
{
Probe(assemblyFile);
}
}
// init plugin type (only one plugin per assembly is allowed)
var exportedTypes = descriptor.ReferencedAssembly.ExportedTypes;
bool pluginFound = false;
bool preStarterFound = !descriptor.Installed;
foreach (var t in exportedTypes)
{
if (typeof(IPlugin).IsAssignableFrom(t) && !t.IsInterface && t.IsClass && !t.IsAbstract)
{
descriptor.PluginType = t;
descriptor.IsConfigurable = typeof(IConfigurable).IsAssignableFrom(t);
pluginFound = true;
}
else if (descriptor.Installed && typeof(IPreApplicationStart).IsAssignableFrom(t) && !t.IsInterface && t.IsClass && !t.IsAbstract && t.HasDefaultConstructor())
{
try
{
var preStarter = Activator.CreateInstance(t) as IPreApplicationStart;
preStarter.Start();
}
catch { }
preStarterFound = true;
}
if (pluginFound && preStarterFound)
{
break;
}
}
result.Success = true;
}
catch (ReflectionTypeLoadException ex)
{
var msg = string.Empty;
foreach (var e in ex.LoaderExceptions)
{
msg += e.Message + Environment.NewLine;
}
var fail = new Exception(msg, ex);
Debug.WriteLine(fail.Message, fail);
throw fail;
}
return(result);
}