Can I load a NET assembly at runtime and instantiate a type knowing only the name

Question

Is it possible to instantiate an object at runtime if I only have the DLL name and the class name  without adding a reference to the assembly in the project  The class implements a interface  so once I instantiate the class  I will then cast it to the interface   Assembly name      library dll    Type name       Company Project Classname     EDIT  I dont have the absolute path of the DLL  so Assembly LoadFile won t work  The DLL might be in the application root  system32  or even loaded in the GAC

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ISomeInterface Activator CreateInstance Assembly LoadFile  somePath   GetTypes   0    SomeInterfaceMethod

User · Answer

Yes  You need to use Assembly LoadFrom to load the assembly into memory  then you can use Activator CreateInstance to create an instance of your preferred type  You ll need to look the type up first using reflection  Here is a simple example   Assembly assembly   Assembly LoadFrom  MyNice dll     Type type   assembly GetType  MyType     object instanceOfMyType   Activator CreateInstance type     Update  When you have the assembly file name and the type name  you can use Activator CreateInstance assemblyName  typeName  to ask the  NET type resolution to resolve that into a type  You could wrap that with a try catch so that if it fails  you can perform a search of directories where you may specifically store additional assemblies that otherwise might not be searched  This would use the preceding method at that point

User · Answer

Yes   I don t have any examples that I ve done personally available right now   I ll post later when I find some   Basically you ll use reflection to load the assembly and then to pull whatever types you need for it   In the meantime  this link should get you started   Using reflection to load unreferenced assemblies at runtime

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ISomeInterface Activator CreateInstance Assembly LoadFile  somePath   GetTypes   0    SomeInterfaceMethod

User · Answer

You can do this things on this way   using System Reflection   Assembly MyDALL   Assembly Load  DALL      DALL name of your assembly Type MyLoadClass   MyDALL GetType  DALL LoadClass       name of your class  object  obj   Activator CreateInstance MyLoadClass

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Yes  it is  you will want to use the static Load method on the Assembly class  and then call then call the CreateInstance method on the Assembly instance returned to you from the call to Load   Also  you can call one of the other static methods starting with  Load  on the Assembly class  depending on your needs

User · Answer

Yes   I don t have any examples that I ve done personally available right now   I ll post later when I find some   Basically you ll use reflection to load the assembly and then to pull whatever types you need for it   In the meantime  this link should get you started   Using reflection to load unreferenced assemblies at runtime

User · Answer

Yes  You need to use Assembly LoadFrom to load the assembly into memory  then you can use Activator CreateInstance to create an instance of your preferred type  You ll need to look the type up first using reflection  Here is a simple example   Assembly assembly   Assembly LoadFrom  MyNice dll     Type type   assembly GetType  MyType     object instanceOfMyType   Activator CreateInstance type     Update  When you have the assembly file name and the type name  you can use Activator CreateInstance assemblyName  typeName  to ask the  NET type resolution to resolve that into a type  You could wrap that with a try catch so that if it fails  you can perform a search of directories where you may specifically store additional assemblies that otherwise might not be searched  This would use the preceding method at that point

User · Answer

Consider the limitations of the different Load  methods  From the MSDN docs        LoadFile does not load files into the LoadFrom context  and does not resolve dependencies using the load path  as the LoadFrom method does    More information on Load Contexts can be found in the LoadFrom docs

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It s Easy   Example from MSDN   public static void Main            Use the file name to load the assembly into the current        application domain      Assembly a   Assembly Load  example           Get the type to use      Type myType   a GetType  Example           Get the method to call      MethodInfo myMethod   myType GetMethod  MethodA           Create an instance      object obj   Activator CreateInstance myType          Execute the method      myMethod Invoke obj  null       Here s a reference link  https   msdn microsoft com en-us library 25y1ya39 aspx

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Starting from Framework v4 5 you can use Activator CreateInstanceFrom   to easily instantiate classes within assemblies  The following example shows how to use it and how to call a method passing parameters and getting return value          Assuming moduleFileName contains full or valid relative path to assembly         var moduleInstance   Activator CreateInstanceFrom moduleFileName   MyNamespace MyClass        MethodInfo mi   moduleInstance Unwrap   GetType   GetMethod  MyMethod           Assuming the method returns a boolean and accepts a single string parameter     bool rc   Convert ToBoolean mi Invoke moduleInstance Unwrap    new object      MyParamValue

User · Answer

Consider the limitations of the different Load  methods  From the MSDN docs        LoadFile does not load files into the LoadFrom context  and does not resolve dependencies using the load path  as the LoadFrom method does    More information on Load Contexts can be found in the LoadFrom docs

User · Answer

Depending how intrinsic this kind of functionality is to your project  you might want to consider something like MEF which will take care of the loading and tying together of components for you

User · Answer

Depending how intrinsic this kind of functionality is to your project  you might want to consider something like MEF which will take care of the loading and tying together of components for you

User · Answer

Activator CreateInstance ought to work   IFace object    IFace Activator CreateInstance   AssemblyName                                                    TypeName                                    Unwrap      Note  The type name must be the fully qualified type   Example   var aray    IList Activator CreateInstance  mscorlib   System Collections ArrayList   Unwrap    aray Add 10    foreach  object obj in aray        Console WriteLine obj

User · Answer

ISomeInterface Activator CreateInstance Assembly LoadFile  somePath   GetTypes   0    SomeInterfaceMethod

User · Answer

You can do this things on this way   using System Reflection   Assembly MyDALL   Assembly Load  DALL      DALL name of your assembly Type MyLoadClass   MyDALL GetType  DALL LoadClass       name of your class  object  obj   Activator CreateInstance MyLoadClass

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Assembly assembly   Assembly LoadFrom  MyAssembly dll     Type type   assembly GetType  MyType     dynamic instanceOfMyType   Activator CreateInstance type     So in this way you can use functions not with getting methodinfo and then invoking it You will do like this instanceOfMyType MethodName    But you can t use Intellisense because dynamic types are typed in runtime not in compile time

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You can load an assembly using  Assembly Load   methods  Using Activator CreateInstance you can create new instances of the type you want  Keep in mind that you have to use the full type name of the class you want to load  for example Namespace SubNamespace ClassName   Using the method InvokeMember of the Type class you can invoke methods on the type   Also  take into account that once loaded  an assembly cannot be unloaded until the whole AppDomain is unloaded too  this is basically a memory leak

User · Answer

Activator CreateInstance ought to work   IFace object    IFace Activator CreateInstance   AssemblyName                                                    TypeName                                    Unwrap      Note  The type name must be the fully qualified type   Example   var aray    IList Activator CreateInstance  mscorlib   System Collections ArrayList   Unwrap    aray Add 10    foreach  object obj in aray        Console WriteLine obj

User · Answer

Yes  it is  you will want to use the static Load method on the Assembly class  and then call then call the CreateInstance method on the Assembly instance returned to you from the call to Load   Also  you can call one of the other static methods starting with  Load  on the Assembly class  depending on your needs

User · Answer

ISomeInterface Activator CreateInstance Assembly LoadFile  somePath   GetTypes   0    SomeInterfaceMethod

User · Answer

Yes  it is  you will want to use the static Load method on the Assembly class  and then call then call the CreateInstance method on the Assembly instance returned to you from the call to Load   Also  you can call one of the other static methods starting with  Load  on the Assembly class  depending on your needs

User · Answer

You can load an assembly using  Assembly Load   methods  Using Activator CreateInstance you can create new instances of the type you want  Keep in mind that you have to use the full type name of the class you want to load  for example Namespace SubNamespace ClassName   Using the method InvokeMember of the Type class you can invoke methods on the type   Also  take into account that once loaded  an assembly cannot be unloaded until the whole AppDomain is unloaded too  this is basically a memory leak

User · Answer

Assembly assembly   Assembly LoadFrom  MyAssembly dll     Type type   assembly GetType  MyType     dynamic instanceOfMyType   Activator CreateInstance type     So in this way you can use functions not with getting methodinfo and then invoking it You will do like this instanceOfMyType MethodName    But you can t use Intellisense because dynamic types are typed in runtime not in compile time

User · Answer

I found this question and some answers very useful  however I did have path problems  so this answer would cover loading library by finding bin directory path   First solution   string assemblyName    library dll   string assemblyPath   HttpContext Current Server MapPath    bin     assemblyName   Assembly assembly   Assembly LoadFrom assemblyPath   Type T   assembly GetType  Company Project Classname    Company Project Classname instance    Company Project Classname  Activator CreateInstance T     Second solution  string assemblyName    library dll   string assemblyPath   HttpContext Current Server MapPath    bin     assemblyName   Assembly assembly   Assembly LoadFile assemblyPath    Company Project Classname  instance    Company Project Classname  assembly CreateInstance  Company Project Classname      You can use same principle for interfaces  you would be creating a class but casting to interface   such as    Company Project Interfacename  instance    Company Project Interfacename  assembly CreateInstance  Company Project Classname      This example is for web application but similar could be used for Desktop application  only path is resolved in different way  for example  Path GetDirectoryName Application ExecutablePath

User · Answer

Yes  You need to use Assembly LoadFrom to load the assembly into memory  then you can use Activator CreateInstance to create an instance of your preferred type  You ll need to look the type up first using reflection  Here is a simple example   Assembly assembly   Assembly LoadFrom  MyNice dll     Type type   assembly GetType  MyType     object instanceOfMyType   Activator CreateInstance type     Update  When you have the assembly file name and the type name  you can use Activator CreateInstance assemblyName  typeName  to ask the  NET type resolution to resolve that into a type  You could wrap that with a try catch so that if it fails  you can perform a search of directories where you may specifically store additional assemblies that otherwise might not be searched  This would use the preceding method at that point

User · Answer

It s Easy   Example from MSDN   public static void Main            Use the file name to load the assembly into the current        application domain      Assembly a   Assembly Load  example           Get the type to use      Type myType   a GetType  Example           Get the method to call      MethodInfo myMethod   myType GetMethod  MethodA           Create an instance      object obj   Activator CreateInstance myType          Execute the method      myMethod Invoke obj  null       Here s a reference link  https   msdn microsoft com en-us library 25y1ya39 aspx

User · Answer

Yes   I don t have any examples that I ve done personally available right now   I ll post later when I find some   Basically you ll use reflection to load the assembly and then to pull whatever types you need for it   In the meantime  this link should get you started   Using reflection to load unreferenced assemblies at runtime

User · Answer

Activator CreateInstance ought to work   IFace object    IFace Activator CreateInstance   AssemblyName                                                    TypeName                                    Unwrap      Note  The type name must be the fully qualified type   Example   var aray    IList Activator CreateInstance  mscorlib   System Collections ArrayList   Unwrap    aray Add 10    foreach  object obj in aray        Console WriteLine obj

User · Answer

Starting from Framework v4 5 you can use Activator CreateInstanceFrom   to easily instantiate classes within assemblies  The following example shows how to use it and how to call a method passing parameters and getting return value          Assuming moduleFileName contains full or valid relative path to assembly         var moduleInstance   Activator CreateInstanceFrom moduleFileName   MyNamespace MyClass        MethodInfo mi   moduleInstance Unwrap   GetType   GetMethod  MyMethod           Assuming the method returns a boolean and accepts a single string parameter     bool rc   Convert ToBoolean mi Invoke moduleInstance Unwrap    new object      MyParamValue

User · Answer

I found this question and some answers very useful  however I did have path problems  so this answer would cover loading library by finding bin directory path   First solution   string assemblyName    library dll   string assemblyPath   HttpContext Current Server MapPath    bin     assemblyName   Assembly assembly   Assembly LoadFrom assemblyPath   Type T   assembly GetType  Company Project Classname    Company Project Classname instance    Company Project Classname  Activator CreateInstance T     Second solution  string assemblyName    library dll   string assemblyPath   HttpContext Current Server MapPath    bin     assemblyName   Assembly assembly   Assembly LoadFile assemblyPath    Company Project Classname  instance    Company Project Classname  assembly CreateInstance  Company Project Classname      You can use same principle for interfaces  you would be creating a class but casting to interface   such as    Company Project Interfacename  instance    Company Project Interfacename  assembly CreateInstance  Company Project Classname      This example is for web application but similar could be used for Desktop application  only path is resolved in different way  for example  Path GetDirectoryName Application ExecutablePath

User · Answer

Yes  it is  you will want to use the static Load method on the Assembly class  and then call then call the CreateInstance method on the Assembly instance returned to you from the call to Load   Also  you can call one of the other static methods starting with  Load  on the Assembly class  depending on your needs

User · Answer

Consider the limitations of the different Load  methods  From the MSDN docs        LoadFile does not load files into the LoadFrom context  and does not resolve dependencies using the load path  as the LoadFrom method does    More information on Load Contexts can be found in the LoadFrom docs

User · Answer

Consider the limitations of the different Load  methods  From the MSDN docs        LoadFile does not load files into the LoadFrom context  and does not resolve dependencies using the load path  as the LoadFrom method does    More information on Load Contexts can be found in the LoadFrom docs

User · Answer

Yes   I don t have any examples that I ve done personally available right now   I ll post later when I find some   Basically you ll use reflection to load the assembly and then to pull whatever types you need for it   In the meantime  this link should get you started   Using reflection to load unreferenced assemblies at runtime

User · Answer

Depending how intrinsic this kind of functionality is to your project  you might want to consider something like MEF which will take care of the loading and tying together of components for you

User · Answer

Yes  You need to use Assembly LoadFrom to load the assembly into memory  then you can use Activator CreateInstance to create an instance of your preferred type  You ll need to look the type up first using reflection  Here is a simple example   Assembly assembly   Assembly LoadFrom  MyNice dll     Type type   assembly GetType  MyType     object instanceOfMyType   Activator CreateInstance type     Update  When you have the assembly file name and the type name  you can use Activator CreateInstance assemblyName  typeName  to ask the  NET type resolution to resolve that into a type  You could wrap that with a try catch so that if it fails  you can perform a search of directories where you may specifically store additional assemblies that otherwise might not be searched  This would use the preceding method at that point

User · Answer

Activator CreateInstance ought to work   IFace object    IFace Activator CreateInstance   AssemblyName                                                    TypeName                                    Unwrap      Note  The type name must be the fully qualified type   Example   var aray    IList Activator CreateInstance  mscorlib   System Collections ArrayList   Unwrap    aray Add 10    foreach  object obj in aray        Console WriteLine obj

User · Answer

You can load an assembly using  Assembly Load   methods  Using Activator CreateInstance you can create new instances of the type you want  Keep in mind that you have to use the full type name of the class you want to load  for example Namespace SubNamespace ClassName   Using the method InvokeMember of the Type class you can invoke methods on the type   Also  take into account that once loaded  an assembly cannot be unloaded until the whole AppDomain is unloaded too  this is basically a memory leak

User · Answer

You can load an assembly using  Assembly Load   methods  Using Activator CreateInstance you can create new instances of the type you want  Keep in mind that you have to use the full type name of the class you want to load  for example Namespace SubNamespace ClassName   Using the method InvokeMember of the Type class you can invoke methods on the type   Also  take into account that once loaded  an assembly cannot be unloaded until the whole AppDomain is unloaded too  this is basically a memory leak

User · Answer

Depending how intrinsic this kind of functionality is to your project  you might want to consider something like MEF which will take care of the loading and tying together of components for you

[c#] Can I load a .NET assembly at runtime and instantiate a type knowing only the name?

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