- 1 year ago
Changing the way Delphi application searches system DLLs
In Delphi, the application uses the default search order to locate system DLLs (Dynamic Link Libraries) when they are required. If you want to change the way your Delphi application searches for system DLLs, you have a few options:
Set the DLL search path programmatically: You can use the
SetDllDirectory
function from the Windows API to modify the DLL search path at runtime. This function allows you to specify a custom directory or directories where your application should search for DLLs. CallSetDllDirectory
with the desired search path before your application starts loading any DLLs. Keep in mind that modifying the DLL search path affects the entire process, not just your Delphi application.Here's an example of how to use
SetDllDirectory
in Delphi:delphitype
TSetDllDirectory = function (lpPathName: PChar): LongBool; stdcall;
procedure SetCustomDllSearchPath(const Path: string);
var
SetDllDirectoryFunc: TSetDllDirectory;
begin
SetDllDirectoryFunc := GetProcAddress(GetModuleHandle('kernel32.dll'), 'SetDllDirectoryW');
if Assigned(SetDllDirectoryFunc) then
SetDllDirectoryFunc(PChar(Path));
end;
Call
SetCustomDllSearchPath
with the desired search path to modify the DLL search order.Use a manifest file: You can create a manifest file for your Delphi application that specifies the desired DLL search order. The manifest file allows you to define search paths for DLLs and override the default search behavior. Refer to the Microsoft documentation on application manifests for more details on how to create and use manifest files in your Delphi application.
Explicitly load DLLs using LoadLibrary: Instead of relying on the default DLL search order, you can explicitly load DLLs using the
LoadLibrary
function from the Windows API.LoadLibrary
allows you to specify the exact path of the DLL you want to load. This gives you full control over the DLL loading process and eliminates reliance on the default search order. However, keep in mind that you'll need to handle the DLL loading and unloading manually.
Choose the approach that best suits your specific requirements and the level of control you need over DLL loading in your Delphi application.