EastRiver.dll中有個函數定議如下: function ReadRecord(hPort: THandle; data: PChar; timeString: PChar; var mark: Char; FirstRecord: Boolean): Boolean; stdcall; external EASTRIVER_API //參數說明: // hPort : 端口句柄, 需要聯機 // data : 讀回的卡號字符串, 緩沖區需大於20位字節長度 // timeString : 讀回的14位刷卡時間字符串, 格式為yyyymmddhhmmss, 緩沖區需大於20位字節長度 // mark : 讀卡機標識字符. // FirstRecord : 是否只讀取最頂端記錄,否則刪除最頂端記錄,讀取下一條記錄 //返回值: // True : 成功 // False : 失敗 在delphi中我是這樣調用的: unit FMAIN; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; type TForm1 = class(TForm) Edit1: TEdit; Button1: TButton; Button2: TButton; Button3: TButton; Edit2: TEdit; Label1: TLabel; Label2: TLabel; procedure FormCreate(Sender: TObject); procedure FormDestroy(Sender: TObject); procedure Button1Click(Sender: TObject); procedure Button2Click(Sender: TObject); procedure Button3Click(Sender: TObject); private hLibModule: HMODULE; { Private declarations } public { Public declarations } end; var Form1: TForm1; implementation {$R *.dfm} procedure TForm1.FormCreate(Sender: TObject); begin hLibModule := LoadLibrary ('EastRiver.dll'); end; procedure TForm1.FormDestroy(Sender: TObject); begin if hLibModule <> 0 then FreeLibrary (hLibModule); end; procedure TForm1.Button3Click(Sender: TObject); var a:integer; data:pchar; timeString:pchar; varmark:char; FirstRecord:Boolean; rre:function (hPort: THandle; data: PChar; timeString: PChar; var mark: Char; FirstRecord: Boolean): Boolean; stdcall; begin a:=strtoint(edit1.Text); //varmark:=edit2.text; rre:= GetProcAddress (hLibModule, 'ReadRecord'); if not assigned (rre) then ShowMessage ('找不到 ReadRecord 函數¡') else begin if rre(a,data,timestring,varmark,firstrecord) then begin showmessage('讀取成功!'); end else begin showmessage('讀取失敗!'); end; end; end; end. 請問以上寫法是否正確.

您好zhong:改成:

引言: unit FMAIN; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; type TForm1 = class(TForm) Edit1: TEdit; Button1: TButton; Button2: TButton; Button3: TButton; Edit2: TEdit; Label1: TLabel; Label2: TLabel; procedure FormCreate(Sender: TObject); procedure FormDestroy(Sender: TObject); procedure Button1Click(Sender: TObject); procedure Button2Click(Sender: TObject); procedure Button3Click(Sender: TObject); private hLibModule: HMODULE; { Private declarations } public { Public declarations } end; var Form1: TForm1; implementation {$R *.dfm} function ReadRecord(hPort: THandle; data: PChar; timeString: PChar; var mark: Char; FirstRecord: Boolean): Boolean; stdcall;//加上原函数的宣告 procedure TForm1.FormCreate(Sender: TObject); begin hLibModule := LoadLibrary ('EastRiver.dll'); end; procedure TForm1.FormDestroy(Sender: TObject); begin if hLibModule <> 0 then FreeLibrary (hLibModule); end; procedure TForm1.Button3Click(Sender: TObject); var a:integer; data:pchar; timeString:pchar; varmark:char; FirstRecord:Boolean; rre:function (hPort: THandle; data: PChar; timeString: PChar; var mark: Char; FirstRecord: Boolean): Boolean; stdcall; begin a:=strtoint(edit1.Text); rre:= GetProcAddress (hLibModule, 'ReadRecord'); if not assigned (rre) then ShowMessage ('找不到 ReadRecord 函數¡') else begin if rre(a,data,timestring,varmark,firstrecord) then begin showmessage('讀取成功!'); end else begin showmessage('讀取失敗!'); end; end; end; end.

不过要是我写会是这样: procedure TForm1.Button3Click(Sender: TObject); var a:integer; data:pchar; timeString:pchar; varmark:char; FirstRecord:Boolean; hLibModule: THandle; begin a:=strtoint(edit1.Text); hLibModule := LoadLibrary ('EastRiver.dll'); if hLibModule <> 0 then begin @ReadRecord := GetProcAddress(hLibModule,'ReadRecord'); if @ReadRecord <> nil then begin ReadRecord(a,data,timestring,varmark,firstrecord); ShowMessage ('讀取成功!') end else begin showmessage('讀取失敗!'); end; freelibrary(hLibModule); end else begin ShowMessage ('找不到 ReadRecord 函數¡'); end; end;