对话框控件（记事本）

var
  Form1: TForm1;
const
defaultfilename='无标题文档';   
implementation                                             //定义

{$R *.dfm}        
begin                                                               //新建
    richedit1.Lines.Clear;                              //清除所有文本
    richedit1.Modified:=False;                      //把Modified属性设为False
    PathName:=DefaultFileName;
    Self.Caption:=DefaultFileName;           //把窗口标题设为'无标题'
end;
begin
if opendialog1.Execute   then                    //打开
RichEdit1.Lines.LoadFromFile(Opendialog1.FileName);
end;
begin                                                              //保存
  SaveDialog1.Filter := '*.txt|*.txt';
  if savedialog1.execute then
     begin
       if extractfileExt(savedialog1.FileName)<>'.txt' then
   SaveDialog1.FileName := ChangeFileExt(SaveDialog1.FileName,'.txt');
   richedit1.PlainText:=True;
   RichEdit1.Lines.SaveToFile(SaveDialog1.FileName);
end;
begin
close;                                                            //关闭
end;
begin
 RichEdit1.CutToClipboard;                      //剪切
end;
begin
RichEdit1.CopyToClipboard;                    //复制
end;
begin
RichEdit1.PasteFromClipboard;              //粘贴
end;
begin
RichEdit1.SelectAll;                                     //全选
end;
begin
RichEdit1.ClearSelection;                          //删除
end;