Delphi 過程與函式
阿新 • • 發佈:2018-11-23
delphi分為過程和函式:
delphi 過程以保留字procedure開始,沒有返回值;函式以保留字function開始,有返回值。
一: 過程的框架:
Procedure 過程名([形參列表])// 引數可選
var
//宣告常量、變數或另一個過程或函式等
begin
語句;
end;
介面如圖所示:
執行前:
程式碼如下:
unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; type TForm1 = class(TForm) Button1: TButton; Edit1: TEdit; procedure Button1Click(Sender: TObject); procedure Myproc(Str: String); private { Private declarations } public { Public declarations } end; var Form1: TForm1; implementation {$R *.dfm} procedure TForm1.Button1Click(Sender: TObject); var x: String; begin x:= Edit1.Text; Myproc(x); end; procedure TForm1.Myproc(Str: String); begin ShowMessage(Str)//就是彈出一個視窗 end; end.
執行後:
二:函式的框架:
Function 函式名(形參表): 返回值型別;
區域性宣告
begin
語句;
end;
function 例項:
程式碼如下:
unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; type TForm1 = class(TForm) Button1: TButton; Edit1: TEdit; Label1: TLabel; Label2: TLabel; Label3: TLabel; procedure Button1Click(Sender: TObject); function add(num1 :Integer;num2 :Integer) :Integer;//定義加法 private { Private declarations } public { Public declarations } end; var Form1: TForm1; implementation {$R *.dfm} procedure TForm1.Button1Click(Sender: TObject); begin add(1,2); end; function TForm1.add(num1 :Integer;num2 :Integer) :Integer;//函式的具體描述 var sum:Integer; begin sum:=num1+num2; Edit1.Text:=inttostr(sum); end; end.
執行結果: