Topendialog组件

opendialog1.InitialDir := ExtractFilePath(Application.ExeName);   //设置打开初始路径，通过Application.ExeName运行程序得到程序路径

if opendialog1.Execute then                 //运行TOpenDialog打开选择文件
  begin
    if LowerCase(ExtractFileExt( opendialog1.FileName)) <> '.xls' then    //选取文件的副类型，然后换成小写
    begin
       opendialog1.FileName:= opendialog1.FileName+'.xls';           
    end;
    edExcelFileName.Text:= opendialog1.FileName;
  end;