Delphi 过程与函数

淩亂°似流年 2022-04-16 05:18 312阅读 0赞

delphi分为过程和函数：

delphi 过程以保留字procedure开始，没有返回值；函数以保留字function开始，有返回值。

###   一：  过程的框架： ###

Procedure 过程名（[形参列表]）// 参数可选
    var
          //声明常量、变量或另一个过程或函数等
    begin
          语句; 
    end;

界面如图所示：

运行前：

![20181117161144564.png][]

代码如下：

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)//就是弹出一个窗口
    
    end;
    
    end.

运行后：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjUyODA4OQ_size_16_color_FFFFFF_t_70][]

### 二：函数的框架： ###

Function 函数名（形参表）: 返回值类型;
           局部声明
    begin
           语句;
    end;

function 实例：

![20181117160619766.png][]

代码如下：

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;//定义加法
      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;//函数的具体描述
    var
        sum:Integer;
    begin
        sum:=num1+num2;
        Edit1.Text:=inttostr(sum);
    end;
    end.

运行结果：

![20181117160742610.png][]

[20181117161144564.png]: /images/20220416/d9d2646f394d48edbfa3c4be4ac4d6d3.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjUyODA4OQ_size_16_color_FFFFFF_t_70]: /images/20220416/ba78a41306a340e5b9302d702133fd23.png
[20181117160619766.png]: /images/20220416/c7f5621a52d34d11a95f98b16da44355.png
[20181117160742610.png]: /images/20220416/f8d5d3e4a8ca4973b72e26b23a0106ae.png