数据窗口dw导出多种格式文件

//==============================================================================
// 函数: uf_dw_exportall()
//------------------------------------------------------------------------------
// 描述: 
//------------------------------------------------------------------------------
// 参数: 
// 	datawindow adw_source   数据
// 	 string as_folder   文件夹名称:保存文件的文件夹
// 	 string as_filename	文件名
//------------------------------------------------------------------------------
// 返回值:  boolean
//------------------------------------------------------------------------------
// 作者:	chenzj		日期: 2021.12.02
//------------------------------------------------------------------------------
// 修改历史: 
//	
//==============================================================================


//dw_1.SaveAs("D:\Desktop\111.txt", Text!, false)

string ls_pathname,ls_file,ls_ext
long ll_return
if adw_source.rowcount()<1 then
    messagebox('提示',"当前数据窗无记录数据,无导出的必要!",exclamation!)
    return false
end if

ll_return=getfilesavename("导出文件",ls_pathname,ls_file,"txt","txt文件(*.txt),*.txt,csv文件(*.csv),*.csv,xls文件(*.xls),*.xls" )

if ll_return<>1 then return false
IF fileexists(ls_pathname) THEN
    ll_return = messagebox('提示', ls_pathname+"已经存在,是否覆盖?",Question!, YesNo!)
    if ll_return=2 then return false
end if

ls_ext = trim(right(ls_pathname,3))
if ls_ext = 'txt' then
    ll_return = adw_source.saveasascii(ls_pathname)
	 ai_type =1
elseif ls_ext = 'csv' then
    ll_return = adw_source.saveasascii(ls_pathname)//,csv!,true)
	 ai_type =2
elseif ls_ext = 'xls' then
   // ll_return = adw_source.saveasascii(ls_pathname)//,Excel!,true)    
	 ll_return = gf_dw_to_excel(adw_source,ls_pathname)
	 ai_type =3
end if

IF ll_return <>1 then
    messagebox('错误',"导出数据失败!",stopsign!)
    return false
END IF 
messagebox('提示',"已成功导出【"+string(adw_source.rowcount())+"】条数据；~r~n 文件位置"+ls_pathname)

return true