Importing Compiled .NET UserControl DLLs at runtime

zeldafreak

I have a project that requires me to load UserControls from DLLs at runtime. Currently I have been able to grab Fields, Methods, Properties, etc, but I need to extract the whole class so I can display it as a control on my form. Currently I have this coded: DirectoryInfo di = new DirectoryInfo(Application.StartupPath + @"\Libraries"); if (di.Exists) { FileInfo[] dList = di.GetFiles("*.dll"); for (int x=0;x

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robin 021y ago
Sorry, but looks like I just forgot visual cpp and can't help you...
zeldafreak21y ago
I'm using MSVC6 to compile the library, not C++.NET if that's what you're thinking. And MSVC is many times faster than the .NET framework, as the Framework is run from libraries on your harddrive, whereas a MSVC library is precompiled and runs from memory. Anyway, that doesn't work for me. I'm guessing because C++.NET's keyword "dllexport" doesn't work from MSVC6. If I'm wrong, please specify what library I need to #include to use that...
robin 021y ago
You know, I've almost forgot cpp... But, if I remember right - if you declare functin in dll for exporting, you should declare it with keyword.... something like this: //cpp dll code int dllexport open_file(..) by the way, I don't think, that VCPP is faster then C# .NET.... ANSI C could be faster in many tasks, but CPP?..
zeldafreak21y ago
Thank you, that worked. I'm not sure if I should just make another topic or whatever, but here is another question. To take advantage of the power and speed of C/C++, I wrote a dll in the language, compiled it, and I used DllImport to do load the dll. (this is only example code!) [DllImport("MyDll.dll")] public static extern int open_file(string path); private void mnuFileOpen() { int error_code = open_file(@"C:\file.dat"); } and then we have open.cpp: #include FILE *fp; int open_file(char * path) { fp = fopen(path, "rb+"); if (fp != NULL) { return 1; } return -1; } Everything compiles fine, but when I run the application, it errors, saying: "Unable to find entry point named "open_file" in dll MyDll.dll." Any ideas on how I could get this to work?
robin 021y ago
Of course. When you are calling mod[0].GetType() without any argument, type that is returned to you is "Module". But you need to get type of your control, so you need to do something like this: Type i = mod[0].GetType("UserControl1"); And don't forget to add namespace, if it is different from your main programm namespace, may be you'll need it this way: Type i = mod[0].GetType("ControlsCollectionNamespace.Control1"); By the way, you can always use Module.GetTypes() function - it returns list of all types. Good luck.
zeldafreak21y ago
Thank you for a quick reply! When I put your code in it errors, saying "Constructor on type System.Reflection.Module not found." Stepped through and found that the error happens on the i.InvokeMember(); function. Thanks, David
robin 021y ago
Try this way: Type i = mod[0].GetType(); UserControl uc = new UserControl(); uc = i.InvokeMember(i.Name, System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.CreateInstance | System.Reflection.BindingFlags.Instance, null, uc, null); // and now you need to add created control to your form // befor adding set needed position, size etc. this.Controls.Add(uc);