使用TDBListBox组件

unit Udblistbox;interfaceuses  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  Dialogs, StdCtrls, Grids, DBGrids, DB, ExtCtrls, DBCtrls, DBTables;type  TForm1 = class(TForm)    DataSource1: TDataSource;    DBGrid1: TDBGrid;    Table1: TTable;    DBNavigator1: TDBNavigator;    Table1CustNo: TFloatField;    Table1Company: TStringField;    Table1Country: TStringField;    DBListBox1: TDBListBox;    Label1: TLabel;   // procedure Button1Click(Sender: TObject);    procedure DBGrid1DblClick(Sender: TObject);   // procedure ListBox1DrawItem(Control: TWinControl; Index: Integer;      //Rect: TRect; State: TOwnerDrawState);    //procedure ListBox1DblClick(Sender: TObject);    procedure FormShow(Sender: TObject);    procedure DBListBox1DblClick(Sender: TObject);  private    { Private declarations }  public    { Public declarations }  end;var  Form1: TForm1;implementation{$R *.dfm}{procedure TForm1.Button1Click(Sender: TObject);begindbgrid1.UpdateAction()end;}procedure TForm1.DBGrid1DblClick(Sender: TObject);begin//listbox1.Visible:=true;end;{procedure TForm1.ListBox1DrawItem(Control: TWinControl; Index: Integer;  Rect: TRect; State: TOwnerDrawState); var  i: Integer;     //定义循环变量 begin   for i:=0 to(listBox1.Items.Count-1) do    //通过循环对选中的Item进行定位   begin     if listBox1.Selected[i] then  //定位后，开始修改     begin         Table1.Edit;   //使数据库表处于编辑状态，便于修改       Table1.FieldByName('Country').AsString:=listbox1.Items.Strings[i];       //将在ListBox中选中的内容赋给当前记录的Country字段       Table1.Post;    //把修改后的变化存入数据库表     end;    end;  end; procedure TForm1.ListBox1DblClick(Sender: TObject); var  i: Integer;     //定义循环变量 begin   for i:=0 to(listBox1.Items.Count-1) do    //通过循环对选中的Item进行定位   begin     if listBox1.Selected[i] then  //定位后，开始修改     begin       Table1.Edit;   //使数据库表处于编辑状态，便于修改       Table1.FieldByName('Country').AsString:=listbox1.Items.Strings[i];       //将在ListBox中选中的内容赋给当前记录的Country字段       Table1.Post;    //把修改后的变化存入数据库表     end;    end; end; }procedure TForm1.FormShow(Sender: TObject); begin  dblistbox1.Items.Clear;  table1.First; while not table1.Eof do   begin    dblistbox1.Items.Add(table1.Fields[1].Value);    table1.Next;   end;   end;procedure TForm1.DBListBox1DblClick(Sender: TObject);var  i: Integer;     //定义循环变量 begin   for i:=0 to(dblistBox1.Items.Count-1) do    //通过循环对选中的Item进行定位   begin     if dblistBox1.Selected[i] then  //定位后，开始修改     begin       Table1.Edit;   //使数据库表处于编辑状态，便于修改       Table1.FieldByName('company').AsString:=dblistbox1.Items.Strings[i];       //将在DBListBox中选中的内容赋给当前记录的company字段       Table1.Post;    //把修改后的变化存入数据库表     end;    end; end;end.