unt_error.pas

一个异常类示例程序

unit Unt_Error;

interface

uses SysUtils;

type
  TMyClass = class
  private
    FNo: Integer;
    procedure SetNo(iValue: Integer);
    function GetNo: Integer;
  public
    constructor Create;
  published
    property No : Integer read GetNo write SetNo;
  end;

  MyError = class(Exception)
    ErrorCode : Integer;
    ErrorInfo : String;
    constructor Create;
  end;

implementation

{ TMyClass }

constructor TMyClass.Create;
begin
  FNo := 0;
end;

function TMyClass.GetNo: Integer;
begin
  Result := FNo
end;

procedure TMyClass.SetNo(iValue: Integer);
begin
  if iValue > 1000 then
    raise MyError.Create
  else FNo := iValue;
end;

{ MyError }

constructor MyError.Create;
begin
  ErrorCode := -1;
  ErrorInfo := '输入数值超过1000！';
end;

end.