Memo1.Lines.LoadFromFile('E:\*\*.txt');

var
  sList: TStringlist;
begin
  sList := TStringList.Create;
   try
  sList.LoadFromFile('C:\a.txt');
  finally
    sList.Free;
  end;
end;

var
  F: Text;  //TextFile 和 Text 是一样的
  FileName: string = 'c:\temp\test.txt';
//写文件
procedure TForm1.Button1Click(Sender: TObject);
begin
  AssignFile(F,FileName);
  Rewrite(F);  //会覆盖已存在的文件
 Writeln(F, '第一行');
  Writeln(F, '第二行');
 CloseFile(F);
end;
//读文件(先执行写文件)
procedure TForm1.Button2Click(Sender: TObject);
var
  s: string;
begin
  AssignFile(F,FileName);
  Reset(F);  //只读打开
 Readln(F, s);   //读取
  ShowMessage(s); //显示: 第一行
  Readln(F, s);   //继续读取
  ShowMessage(s); //显示: 第二行
 CloseFile(F);
end;
//追加
procedure TForm1.Button3Click(Sender: TObject);
begin
  AssignFile(F,FileName);
  Append(F);  //打开准备追加
 Writeln(F, '第三行');
  Writeln(F, '第四行');
 CloseFile(F);
end;
//读取全部(需要Memo帮忙显示)
procedure TForm1.Button4Click(Sender: TObject);
var
  s: string;
begin
  AssignFile(F,FileName);
  Reset(F);  //只读打开
 Memo1.Clear;
  while not Eof(F) do
  begin
    Readln(F, s);
    Memo1.Lines.Add(s);
  end;
 CloseFile(F);
end;