Calling multiple dll imports with the same method name

Question

I'm importing several unmanaged c++ DLL's into my project however the imported DLLs have the same method name which causes compiler issues. For example;

unsafe class Myclass
{
   [DllImport("myfirstdll.dll")]
   public static extern bool ReturnValidate(long* bignum);

   [DllImport("myseconddll.dll")]
   public static extern bool ReturnValidate(long* bignum);

   public Myclass
   {
      int anum = 123;
      long passednum = &anum;
      ReturnValidate(passsednum);
   }
}

Now what I'd like to do would be rename the method on import. Something like;

[DllImport("myseconddll.dll")]
public static extern bool ReturnValidate(long bignum) AS bool ReturnValidate2(long bignum);

Is this possible?

Answer 1

Use the EntryPoint property of DllImport attribute.

[DllImport("myseconddll.dll", EntryPoint = "ReturnValidate")]
public static extern bool ReturnValidate2(long bignum);

Now when you call ReturnValidate2 in your C# code, you will effectively call ReturnValidate on myseconddll.dll.

Answer 2

You could provide any name for your imported function, you should only specify in DllImport the name of the function in it, using EntryPoint property. So you code could look like:

[DllImport("myfirstdll.dll", EntryPoint="ReturnValidate")]  
public static extern bool ReturnValidate1(long bignum);  

[DllImport("myseconddll.dll", EntryPoint="ReturnValidate")]  
public static extern bool ReturnValidate2(long bignum);  

Answer 3

Use the EntryPoint parameter:

[DllImport("myfirstdll.dll", EntryPoint="ReturnValidate")]
public static extern bool ReturnValidate1(long bignum);

[DllImport("myseconddll.dll", EntryPoint="ReturnValidate")]
public static extern bool ReturnValidate2(long bignum);

Documentation:
http://msdn.microsoft.com/en-us/library/system.runtime.interopservices.dllimportattribute.aspx
http://msdn.microsoft.com/en-us/library/system.runtime.interopservices.dllimportattribute.entrypoint.aspx