Call function from DLL

Question

It is well known that you can have functions in a dll, reference the DLL and then call the functions from your main executable. I like to know if the reverse way is also possible? So I like to call a function in the main executable from the dll, without having the actual function that should be called inside the dll. Reason: I am working on a pluginsystem.

Answer 1

You're sort of comparing apples and oranges: referencing a dll by the build system is completely different from a plugin system where everything happens at runtime. Typically a plugin system where you would want to call some functions from the plugin host (your exe) would be like this (simplified):

//in a common project
//functions from the host that will be callable by the plugin
public interface PluginHost
{
  void Foo();
}

//the plugin
public interface Plugin
{
  void DoSomething( PluginHost host );
}

//in the exe
class ThePluginHost : PluginHost
{
  //implement Foo
}

//in the plugin
class ThePlugin : Plugin
{
  //implement DoSomething,
  //has access to exe methods through PluginHost
}

//now al that's left is loading the plugin dll dynamically,
//and creating a Plugin object from it.
//Can be done using Prism/MEF etc, that's too broad of a scope for this answer
PluginHost host = new ThePluginHost();
Plugin plugin = CreatePluginInstance( "/path/to/dll" );
plugin.DoSomething( host );

Answer 2

是的，可以在项目中添加可执行文件作为参考，并且可以像从引用的dll调用函数一样使用它们