unit1.pas

《Delphi7编程100例》代码,书配资料

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, DB, DBTables, Grids, DBGrids, StdCtrls, ExtCtrls;

type
  TForm1 = class(TForm)
    RadioGroup1: TRadioGroup;
    RadioButton1: TRadioButton;
    RadioButton2: TRadioButton;
    RadioButton3: TRadioButton;
    Button1: TButton;
    Edit1: TEdit;
    Label1: TLabel;
    DBGrid1: TDBGrid;
    DataSource1: TDataSource;
    Table1: TTable;
    Table1EmpNo: TIntegerField;
    Table1LastName: TStringField;
    Table1FirstName: TStringField;
    Table1PhoneExt: TStringField;
    Table1HireDate: TDateTimeField;
    Table1Salary: TFloatField;
    Edit2: TEdit;
    procedure FormCreate(Sender: TObject);
    procedure RadioButton1Click(Sender: TObject);
    procedure RadioButton2Click(Sender: TObject);
    procedure RadioButton3Click(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  Checked:array [1..3]of boolean;
  MinNo,MaxNo:integer;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  Edit2.Enabled:=False;
  Table1.Open;
  Table1.FindLast;
  MaxNo:=Table1EmpNo.Value;
  Table1.FindFirst;;
  MinNo:=Table1EmpNo.Value;
end;

procedure TForm1.RadioButton1Click(Sender: TObject);
begin
  RadioButton1.Checked:=True;
  Showmessage('编号的最大范围为'+inttostr(MinNo)+'~'+inttostr(MaxNo));
end;

procedure TForm1.RadioButton2Click(Sender: TObject);
begin
  RadioButton2.Checked:=True;
  Showmessage('编号的最大范围为'+inttostr(MinNo)+'~'+inttostr(MaxNo));
end;

procedure TForm1.RadioButton3Click(Sender: TObject);
begin
  RadioButton3.Checked:=True;
  Edit2.Enabled:=True;
  Showmessage('编号的最大范围为'+inttostr(MinNo)+'~'+inttostr(MaxNo)+';请分别输入!');
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  if (not RadioButton1.Checked)and (not RadioButton2.Checked)and (not RadioButton3.Checked)then
  begin
    showmessage('请选择查询方式!');
    Exit;
  end;
  if RadioButton1.Checked then
    if Table1.FindKey([Edit1.Text]) then
      showmessage('您要查询的记录已找到!') else
      showmessage('对不起,没有您要查询的记录!');
  if RadioButton2.Checked then
  begin
    Table1.FindNearest([Edit1.text]);
    showmessage('已找到相关记录!');
  end;
  if RadioButton3.Checked then
  begin
    Table1.SetRange([Edit1.Text],[Edit2.Text]);
    Edit2.Enabled:=False;
  end;
end;

end.