插件加载到 appDomain 的 mySQL 错误

Question

我正在努力使用我的插件进行动态加载。我正在将插件加载到 appdomain 中，但是当我的插件尝试执行任何 mySQL 代码时出现以下异常：

MySql.Data.MySqlClient.MySqlException 未处理
消息=拒绝访问 对于用户''@'localhost'（使用 密码：否）

这是 Plugins.cs 上的代码：

public class Plugins {

private static List<PluginContainer> PluginList;
public static bool PluginsAreLoaded {
get {
if(PluginList==null) {
return false;
}
else {
return true;
}
}
}

public static void LoadAllPlugins(Form host) {
//add assemblies in OD folder to appDomain
Assembly[] list = AppDomain.CurrentDomain.GetAssemblies();
AppDomain appDomainAnesthesia AppDomain.CreateDomain("appDomainAnesthesia");
for(int i=0;i<ProgramC.Listt.Count;i++) {
string dllPathWithVersion = String.Empty;
if(!ProgramC.Listt[i].Enabled) {
continue;
}
if(ProgramC.Listt[i].PluginDllName=="") {
continue;
}
string dllPath=ODFileUtils.CombinePaths(Application.StartupPath,ProgramC.Listt[i].PluginDllName);
if(dllPath.Contains("[VersionMajMin]")) {
Version vers=new Version(Application.ProductVersion);
dllPathWithVersion=dllPath.Replace("[VersionMajMin]",vers.Major.ToString()+"."+vers.Minor.ToString());
dllPath=dllPath.Replace("[VersionMajMin]","");//now stripped clean
if(File.Exists(dllPathWithVersion)){
File.Copy(dllPathWithVersion,dllPath,true);
}
}
if(!File.Exists(dllPath)) {
continue;
}
//add our plugin to the appDomain
try {                       
string typeName = Path.GetFileNameWithoutExtension(dllPath) + ".Plugin";
PluginBase plugin = (PluginBase)appDomainAnesthesia.CreateInstanceAndUnwrap(Path.GetFileNameWithoutExtension(dllPathWithVersion), typeName);
appDomainAnesthesia.Load(Path.GetFileNameWithoutExtension(dllPathWithVersion));
plugin.Host=host;
}
catch(Exception ex) {
MessageBox.Show(ex.Message);
continue;//don't add it to plugin list.
}       
PluginContainer container=new PluginContainer();
container.Plugin=plugin;
container.ProgramNum=ProgramC.Listt[i].ProgramNum;
PluginList.Add(container);
}

}

这里是插件库：

public abstract class PluginBase : MarshalByRefObject {
private Form host;
///<summary>This will be a refrence to the main FormOpenDental so that it can be used by    the plugin if needed.  It is set once on startup, so it's a good place to put startup code.</summary>
public virtual Form Host { 
get { 
return host; 
}
set {
host=value; 
}
}

///<summary>These types of hooks are designed to completely replace the existing functionality of specific methods.  They always belong at the top of a method.</summary>
public virtual bool HookMethod(object sender,string methodName,params object[] parameters) {
return false;//by default, no hooks are implemented.
}
///<summary>These types of hooks allow adding extra code in at some point without disturbing the existing code.</summary>
public virtual bool HookAddCode(object sender,string hookName,params object[] parameters) {
return false;
}
public virtual void LaunchToolbarButton(long patNum) {
}

}

插件容器：

class PluginContainer {
public PluginBase Plugin;
public long ProgramNum;

最后，插件：

public class Plugin : PluginBase  {
private Form host;
public AnestheticData AnesthDataCur;
public AnestheticRecord AnestheticRecordCur;
public Patient PatCur;
public string SourceDirectory;
public string DestDirectory;
public System.ComponentModel.IContainer components;
public long patNum;
public static Procedure procCur;
public static List<Procedure> ProcList;
public static ODtextBox textNotes;
public override Form Host {
get { 
return host; 
}
set {
host=value;
ConvertAnesthDatabase.Begin();//if this crashes, it will bubble up and result in the plugin not loading.                                                                                                 }
}

它轰炸了

plugin.Host=host; 

Plugins.cs 上的行来自 ConverAnesthDatabase.Begin() 方法，因为那里有多个 mySQL 语句。

我可以访问 mySQL 数据库，所以这不是问题。

如何解决此错误？

Answer 1

尽量不要“扩展”您的 PluginBase 而是使用接口：

public interface IPlugin
{
    Form Host {get; set; }
    bool HookMethod(object sender,string methodName,params object[] parameters);
    bool HookAddCode(object sender,string hookName,params object[] parameters);
    void LaunchToolbarButton(long patNum);
}

然后

public class Plugin : IPlugin
{
    ...
}