unit1.pas

本光盘是《Delphi 7应用教程》一书的配套光盘

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Label1: TLabel;
    Edit1: TEdit;
    Label2: TLabel;
    Edit2: TEdit;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation


{$R *.dfm}
Function weisum( m:Integer):Integer;//注意自定义函数一般在事件代码代码之前定义
   var
     sum,r:integer;
begin
  sum:=0;
  repeat
     r:=m mod 10;   //m除10的余数(即m的个位数)赋值给变量r
     m:=m div 10;   //m除10的商再赋值m
     sum:=sum+r;    //把取出的位加到和中去
  until(m=0);        //直到m等于0时为止
  weisum:=sum;       //把各位数字和赋值给函数名，作为函数的返回值

end;

procedure TForm1.Button1Click(Sender: TObject);
var
  k:integer;        //存放要求各位数字和的数
  s:integer;        //存放求得的各位数字之和
begin
  k:=StrToInt(Edit1.Text);  //字符串转换成整数
  s:=weisum(k);
  Edit2.Text:=IntToStr(s); //将各位数字之和显示在编辑框2中
end;

end.