我正在尝试将DLL文件加载到单独的应用程序域中，并在DLL文件中调用方法，并从中获取一些响应。应用程序启动时，项目bin文件夹中不存在DLL文件，该DLL文件是从另一个文件夹加载的。在完成DLL文件后，我想卸载刚刚创建的应用程序域。
步骤：
这是我到目前为止尝试过的
这是MyAssembly.dll中的代码
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
namespace MyAssembly
{
public class MyClass
{
public static string MyMethod()
{
return "Hello there, this is message from MyAssembly";
}
}
}
这是我加载DLL文件的方式
using System.Diagnostic;
using System.IO;
private class ProxyClass : MarshalByRefObject
{
public void LoadAssembly()
{
AppDomain dom;
string domainName = "new:" + Guid.NewGuid();
try
{
//Create the app domain
dom = AppDomain.CreateDomain(domainName, null, new AppDomainSetup
{
PrivateBinPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "bin"),
ApplicationBase = AppDomain.CurrentDomain.BaseDirectory,
ConfigurationFile = AppDomain.CurrentDomain.SetupInformation.ConfigurationFile,
ApplicationName = AppDomain.CurrentDomain.SetupInformation.ApplicationName,
ShadowCopyFiles = "true",
ShadowCopyDirectories = "true",
LoaderOptimization = LoaderOptimization.SingleDomain,
});
string dllPath = @"C:\MyProject\MyAssembly.dll";//the path to my assembly file I want to load
//load the assembly to the new app domain
Assembly asm = dom.Load(File.ReadAllBytes(dllPath));//Error occurred at here
Type baseClass = asm.GetType("MyAssembly.MyClass");
MethodInfo targetMethod = baseClass.GetMethod("MyMethod");
string result = targetMethod.Invoke(null, new object[]{});
/*Do something to the result*/
}
catch(Exception ex)
{
Debug.WriteLine(ex.Message);
Debug.WriteLine(ex.ToString());
}
finally
{
//Finally unload the app domain
if (dom != null) AppDomain.Unload(dom);
}
}
}
public void BeginLoadDll()
{
ProxyClass proxy = new ProxyClass();
proxy.LoadAssembly();
//OR like this, which gave me same error message as well
//var dom = AppDomain.CreateDomain("new:" + Guid.NewGuid(), null, new AppDomainSetup
// {
// PrivateBinPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "bin"),
// ApplicationBase = AppDomain.CurrentDomain.BaseDirectory,
// ConfigurationFile = AppDomain.CurrentDomain.SetupInformation.ConfigurationFile,
// ApplicationName = AppDomain.CurrentDomain.SetupInformation.ApplicationName,
// ShadowCopyFiles = "true",
// ShadowCopyDirectories = "true",
// LoaderOptimization = LoaderOptimization.SingleDomain,
// });
//ProxyClass proxy = (ProxyClass)dom.CreateInstanceAndUnwrap(
// typeof(ProxyClass).Assembly.FullName, typeof(ProxyClass).FullName);
//pr.LoadAssembly(watcherData, filePath);
}
到目前为止，这是我观察到的东西，我不确定那是我自己还是我错过了什么
-如果在应用程序启动之前项目bin文件夹中存在“ MyAssembly.dll”，则可以加载dll文件
-如果在应用程序启动之前项目bin文件夹中不存在“ MyAssembly.dll”，而是将其加载到项目bin文件夹以外的其他位置，则无法加载dll文件。例如，项目bin文件夹是“ C：\ Main \ MyMainProject \ MyMainProject \ bin”，并且DLL是从C：\ MyProject \ MyAssembly.dll加载的”
-如果我将“ MyAssembly.dll”文件移动到bin文件夹中（使用File.Copy()或File.Move()），它将以某种方式停止其余代码的执行。
我收到的错误消息
Could not load file or assembly 'MyAssembly, Version=1.0.0.0,
Culture=neutral, PublicKeyToken=2c20c56a5e1f4bd4' or one of its dependencies.
The system cannot find the file specified.
编辑
我知道我可以使用Assembly.LoadFrom(@"PATH\TO\MY\DLL")，但是这个问题是我无法卸载DLL
答案 0 :(得分：1)
经过几天的研究，我终于使它起作用了。下面是我的最终工作代码。
有用的参考链接帮助我实现了这一目标
C# reflection - load assembly and invoke a method if it exists
Using AppDomain in C# to dynamically load and unload dll
MyAssembly.dll中的代码与问题中的相同。我还意识到我也可以返回对象类型。
如何将DLL文件加载到单独的应用程序域中并卸载应用程序域
public void MethodThatLoadDll()
{
AppDomain dom = null;
//declare this outside the try-catch block, so we can unload it in finally block
try
{
string domName = "new:" + Guid.NewGuid();
//assume that the domName is "new:50536e71-51ad-4bad-9bf8-67c54382bb46"
//create the new domain here instead of in the proxy class
dom = AppDomain.CreateDomain(, null, new AppDomainSetup
{
PrivateBinPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "bin"),
ApplicationBase = AppDomain.CurrentDomain.BaseDirectory,
ConfigurationFile = AppDomain.CurrentDomain.SetupInformation.ConfigurationFile,
ApplicationName = AppDomain.CurrentDomain.SetupInformation.ApplicationName,
ShadowCopyFiles = "true",
ShadowCopyDirectories = "true",/*yes they are string value*/
LoaderOptimization = LoaderOptimization.SingleDomain,
DisallowBindingRedirects = false,
DisallowCodeDownload = true,
});
ProxyClass proxy = (ProxyClass)dom.CreateInstanceAndUnwrap(
typeof(ProxyClass).Assembly.FullName, typeof(ProxyClass).FullName);
string result = proxy.ExecuteAssembly("MyParam");
/*Do whatever to the result*/
}
catch(Exception ex)
{
//handle the error here
}
finally
{
//finally unload the app domain
if(dom != null) AppDomain.Unload(dom);
}
}
我的类继承了MarshalByRefObject
private class ProxyClass : MarshalByRefObject
{
//you may specified any parameter you want, if you get `xxx is not marked as serializable` error, see explanation below
public string ExecuteAssembly(string param1)
{
/*
* All the code executed here is under the new app domain that we just created above
* We also have different session state here, so if you want data from main domain's session, you should pass it as a parameter
*/
//load your DLL file here
Debug.WriteLine(AppDomain.CurrentDomain.FriendlyName);
//will print "new:50536e71-51ad-4bad-9bf8-67c54382bb46" which is the name that we just gave to the new created app domain
Assembly asm = Assembly.LoadFrom(@"PATH/TO/THE/DLL");
Type baseClass = asm.GetType("MyAssembly.MyClass");
MethodInfo targetMethod = baseClass.GetMethod("MyMethod");
string result = targetMethod.Invoke(null, new object[]{});
return result;
}
}
您可能会遇到的常见错误
'xxx' is not marked as serializable
如果您尝试将自定义类作为参数传递，则可能会发生这种情况
public void ExecuteAssembly(MyClass param1)
在这种情况下，将[Serializable]放在MyClass上，像这样
[Serializable]
public class MyClass { }