Question

For example, I want to build a DLL exporting a function called ShowDialog, which displays a dialog and changes the text in one of the dialog buttons. The dialog and all other resources should be bundled in the DLL.

I did a quick test and when the DLL tries GetDlgItem() with a certain control ID, it gets a null pointer back. I’m assuming more steps are required to handle the resources properly in this case.

Answer 1

From MSDN:

By default, MFC uses the resource handle of the main application to load the resource template. If you have an exported function in a DLL, such as one that launches a dialog box in the DLL, this template is actually stored in the DLL module. You need to switch the module state for the correct handle to be used. You can do this by adding the following code to the beginning of the function:

AFX_MANAGE_STATE(AfxGetStaticModuleState());