unit DllUtils;    interface    uses   Windows, Messages, SysUtils, Classes, Forms, Controls;    type   IPlugin = interface   ['{D3F4445A-C704-42BC-8283-822541668919}']       function CreateForm(hMainForm: THandle): THandle;     procedure DestroyForm;     function ShowModalForm: Integer;   end;     TCreatePluginFunc = function (hApp: THandle): IPlugin; stdcal; function DllCreatePlugin(hLib, hApp: THandle): IPlugin; implementation resourcestring sErrorLoadingDLL = '無法載入模組!'; sErrorDllProc = '無法呼叫 DLL 函式: %s'; const SDllCreatePluginFuncName = 'CreatePlugin'; function DllCreatePlugin(hLib, hApp: THandle): IPlugin; var pProc: TFarProc; CreatePluginFunc: TCreatePluginFunc; begin Result := nil; if hLib = 0 then Exit; pProc := GetProcAddress(hLib, PChar(SDllCreatePluginFuncName)); if pProc = nil then raise Exception.CreateFmt(sErrorDllProc, [SDllCreatePluginFuncName]); CreatePluginFunc := TCreatePluginFunc(pProc); Result := CreatePluginFunc(hApp); end; end. 請問以上的code藍色部分的宣告我不是很了解,請問有人可以解釋給我了解嗎?為什麼 發表人 -

It defines a function type "TCreatePluginFunc", which is accepting parameters hLib, hApp as handles and returning an interface IPlugin. stdcal (typing error? should be stdcall) is used to specify calling convention for this kind of function.

引言: It defines a function type "TCreatePluginFunc", which is accepting parameters hLib, hApp as handles and returning an interface IPlugin. stdcal (typing error? should be stdcall) is used to specify calling convention for this kind of function.

那請問通常function 不是應該有function name,為什麼這個沒有name,還有一般function通常都沒有定義function type,而這種function為何要定義function type,通常用於何處?? 因為我的觀念非常不好,所以想請教一下,釐清一些觀念

Becasue GetProcAddress returns ONLY an address (i.e. a pointer), you need to "type cast" it as a function in order to use it. For example:

type
    TMyFunction = function(Value: integer):integer;
...
function Func1(Value: integer): integer;
function Func2(Value: integer): integer;
...
var
    MyFunc : TMyFunction
....
    MyFunc := Func1;
    i := MyFunc(1); // same as i := Func1(1)
    MyFunc := Func2;
    i := MyFunc(1); // same as i := Func2(1)