如何实现窗体继承，并对此窗体上的控件进行控制，请给出例程，谢谢！

Question

新建一个项目pruject1，做好一个form1（上边包括几个form的公用控件及其代码），然后file\new\other在new items对话框中选择pruject1项，然后再选择form1，按ok，这样你就建立了继承form1的一个新form.很简单，我是菜鸟，不会用代码，不过这个方法很有效。

Answer 1

窗体继承是Delphi开发中应用最普遍，最简单的一种，对于整个系统的界面风格一致性有很大帮助，但基类窗体也不宜太细微化，否则他的后代就丧失了灵活性，反倒失去了继承的优势。

Answer 2

代码来了：
unit untBFrm;interfaceuses
  untInit, untBasicServices, Grids, DBGrids,
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, ComCtrls, ExtCtrls, DBCtrls,DB;//type TDispType=(dtNormal, dtWarning, dtError ,dtInformation, dtConfirmation, dtCustom);type
  TfrmBase = class(TForm)
    procedure FormCreate(Sender: TObject);
    procedure ClearText(Sender: TObject);
    procedure FormShow(Sender: TObject);
    procedure DrawColumnCell(Sender: TObject; const Rect: TRect;
      DataCol: Integer; Column: TColumn; State: TGridDrawState);virtual;
    procedure TitleClick(Column: TColumn);virtual;
    procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);
  private//    FGetUserNo: String;
//    FGetSysDate: TDateTime;
    function GetSysDate:TDateTime;
    function GetUserNo:String;//    procedure ourDeleted(ANavigator: TDBNavigator; Button: TNavigateBtn;
//      ADeleteFieldName, AValue: string);
  public
{    bLogicDelete:boolean;   //逻辑删除还是物理删除，True时Status='D'
    
    procedure ANavigatorBeforeAction(Sender: TObject; Button: TNavigateBtn;
      AFieldName, Avalue: string);   }    procedure DispMsg(MsgId:String; const DispType:TDispType=dtNormal; Showed:Boolean=True);
    property SysDate: TDateTime read GetSysDate;
    property UserNo: String read GetUserNo;
  end;var
  frmBase: TfrmBase;implementation{$R *.DFM}{
// 在Navigator的BeforeAction中调用
procedure TfrmBase.ANavigatorBeforeAction(Sender: TObject;
  Button: TNavigateBtn; AFieldName, Avalue: string);
begin
  case Button of
    nbFirst  : ;
    nbPrior  : ;
    nbNext   : ;
    nbLast   : ;
    nbInsert : ;
    nbDelete :
      begin
        if bLogicDelete then
        begin
          ourDeleted(TDBNavigator(Sender), Button, AFieldName, Avalue);
          abort;
        end;
      end;
    nbEdit   : ;
    nbPost   : ;
    nbCancel : ;
    nbRefresh: ;
  end;end;// 使用 TDBNavigator 上的删除时要调用本函数
// ADeleteFieldName-->一般是状态栏位,AValue-->标记为删除的值
procedure TfrmBase.ourDeleted(ANavigator: TDBNavigator;
  Button: TNavigateBtn; ADeleteFieldName, AValue: string);
var deleteField:TField;
    strOld,strNow:string;
begin
  deleteField:=ANavigator.DataSource.DataSet.FindField(ADeleteFieldName);
  if deleteField=nil then
  begin
    showmessage(ADeleteFieldName+' is not exist !');
    Exit;
  end;
  strNow:=UpperCase(trim(AValue));
  strOld:=UpperCase(trim(deleteField.AsString));
  if strOld<>strNow then
  begin
    ANavigator.DataSource.DataSet.Edit;
    if deleteField.ReadOnly then
      deleteField.ReadOnly:=False;
    deleteField.AsString:=strNow;
    ANavigator.DataSource.DataSet.Post;
  end;
end;     }
function TfrmBase.GetSysDate;
begin
  //Result:=frmLogin.SysDate; //This should be gotten after system login
  Result:=now;
end;function TfrmBase.GetUserNo;
begin
  //Result:=frmLogin.UserNo; //This should be gotten after system login
  Result:='User1';  
end;procedure TfrmBase.DispMsg(MsgId:String; const DispType:TDispType=dtNormal; Showed:Boolean=True);
var
  MsgText: string;
begin
  MsgText:=frmLogin.GetMsg(MsgId, Showed);
  if DispType=dtNormal then
    Application.MessageBox(PChar(MsgText),PChar(Screen.ActiveForm.Caption),MB_OK)
  else if DispType=dtError then
    MessageDlg(MsgText,mtError,[mbok],0)
  else if DispType=dtWarning then
    MessageDlg(MsgText,mtWarning,[mbok],0)
  else
    Exception.Create('Invalid DispType');
end;procedure TfrmBase.FormCreate(Sender: TObject);
begin
  //CheckRights(self, UserInfor);
end;procedure TfrmBase.ClearText(Sender: TObject);
var
  i:integer;
  aParent:TWinControl;
begin
  aParent:=TWinControl(Sender).Parent;
  if aParent=nil then Exit;  for i := 0 to aParent.ControlCount-1 do
    if aParent.Controls[I] is TEdit then
      TEdit(aParent.Controls[I]).Clear
{    else if aParent.Controls[I] is TComboBox then
      TComboBox(aParent.Controls[I]).Text:='';   }
    else if (aParent.Controls[I] is TComboBox)then
      if trim(TComboBox(aParent.Controls[I]).Items[0])='' then
        TComboBox(aParent.Controls[I]).ItemIndex:=0
      else
        TComboBox(aParent.Controls[I]).Text:='';  
end;procedure TfrmBase.FormShow(Sender: TObject);
var
  i:integer;
begin
  for i := 0 to ComponentCount-1 do
    if components[i] is TDateTimePicker then
      TDateTimePicker(components[I]).Date:=date;  
end;procedure TfrmBase.DrawColumnCell(Sender: TObject; const Rect: TRect;
  DataCol: Integer; Column: TColumn; State: TGridDrawState);
begin
  if gdSelected in State then Exit;
  if (TDBGrid(Sender).DataSource = nil) or (TDBGrid(Sender).DataSource.DataSet = nil) then Exit;  if TDBGrid(Sender).DataSource.DataSet.RecNo mod 2 = 0 then
    TDBGrid(Sender).Canvas.Brush.Color := clInfoBk
  else
    TDBGrid(Sender).Canvas.Brush.Color := RGB(191, 255, 223);  TDBGrid(Sender).DefaultDrawColumnCell(Rect, DataCol, Column, State);  TDBGrid(Sender).Canvas.Pen.Color := $00C08000;
  TDBGrid(Sender).Canvas.MoveTo(Rect.Left, Rect.Bottom);
  TDBGrid(Sender).Canvas.LineTo(Rect.Right, Rect.Bottom);
  TDBGrid(Sender).Canvas.LineTo(Rect.Right, Rect.Top);
end;procedure TfrmBase.TitleClick(Column: TColumn);
begin
  untBasicServices.DBGridTitleSort(Column);
end;procedure TfrmBase.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
var
  i:integer;
  bfalg:Boolean;
  DataSource:TDataSource;
begin
  inherited;
  bfalg:=False;
  for i := 0 to ComponentCount-1 do
    if Components[i] is TDBEdit then
    begin
      DataSource:=TDBEdit(Components[I]).DataSource;
      if DataSource=nil then Continue;
      bfalg:=(DataSource.State in [dsEdit,dsInsert]);
      break;
    end
    else
    if Components[i] is TDBComboBox then
    begin
      DataSource:=TDBComboBox(Components[I]).DataSource;
      if DataSource=nil then Continue;
      bfalg:=(DataSource.State in [dsEdit,dsInsert]);
      break;
    end
    else
    if Components[i] is TDBMemo then
    begin
      DataSource:=TDBMemo(Components[I]).DataSource;
      if DataSource=nil then Continue;
      bfalg:=(DataSource.State in [dsEdit,dsInsert]);
      break;
    end;  if bfalg then
  begin
    MessageDlg('You are Editting data, please Save or Cancel Before Exit!',
               mtWarning,[mbOk], 0);
    CanClose:=False;
  end
  else CanClose:=True;end;end.

Answer 3

这个是继承上一个的。现在感觉这样作也有不好的地方，想改用FRAME作这些可能
会好点unit untNFrm;interfaceuses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  UNTBFRM, ExtCtrls, ImgList, ComCtrls, Menus, ToolWin, ActnList, StdCtrls,
  Buttons;type
  TfrmNormal = class(TfrmBase)
    stb1: TStatusBar;
    iml1: TImageList;
    acl1: TActionList;
    pnl1: TPanel;
    spd1: TSpeedButton;
    tmr1: TTimer;
    procedure spd1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  frmNormal: TfrmNormal;implementation{$R *.DFM}procedure TfrmNormal.spd1Click(Sender: TObject);
begin
  inherited;
  self.Close;
end;end.