How do I call an external DLL in Delphi?
It should be: function I2C_GetNumChannels(out numChannels: Longword): FT_Result; stdcall; external ‘libmpsse. dll’; The function you are calling accepts the address of a 32 bit unsigned integer.
How do I use a DLL in Delphi?
Start a new DLL project in Delphi (Click File −> New, select DLL). Save the project as delhpdll….Then you need an application, to call the DLL:
- Start a new “main” application project.
- Make whatever GUI controls you need to test the DLL.
- Fill in the source code for interfacing the DLL as given below.
What is procedure in Delphi?
A procedure is a routine that does not return a value. Function calls, because they return a value, can be used as expressions in assignments and operations.
How do I create a DLL in Delphi?
To create one you use the File -> New -> Other menu entry to open a dialog where you can select the project type you want to create. There is one called “DLL Wizard”; that’s the one we need here. Select it and press OK and Delphi will automatically create a new DLL file project for you.
What is DLL in Delphi?
Delphi allows not only to create applications but also DLL files. A DLL file (short for dynamic link library) is a special kind of executable that cannot be started by itself, but exports procedures and functions (called “Entry Points”) for other executables to call.
What is Stdcall in Delphi?
Description. The stdcall directive uses the Windows standard calling convention: arguments are pushed onto the stack, starting with the rightmost argument. The subroutine is responsible for popping the arguments from the stack.
How do I create a class in Delphi?
Defining New Classes (Delphi)
- In the IDE, start with a project open and choose File > New > Unit to create a new unit where you can define the new class.
- Add the uses clause and type section to the interface section.
- In the type section, write the class declaration.
What is the difference between Stdcall and Cdecl?
__cdecl is the default calling convention for C and C++ programs. Because the stack is cleaned up by the caller, it can do vararg functions. The __cdecl calling convention creates larger executables than __stdcall, because it requires each function call to include stack cleanup code.
What is Stdcall?
__stdcall is the standard calling convention for Win32 system calls. Wikipedia covers the details. It primarily matters when you are calling a function outside of your code (e.g. an OS API) or the OS is calling you (as is the case here with WinMain).
What are classes in Delphi?
Classes in Delphi A Class consists of fields, methods and properties which defines character and behavior of an object. Instances of a Class are called as Objects and fields, methods are called as class members. -> A Field is essentially a variable that is part of an object.
What is a class function Delphi?
In Delphi, a method is a procedure or function that performs an operation on an object. A class method is a method that operates on a class reference instead of an object reference.