;批量读取点的DN值
pro txtpoints
  envi,/restore_base_save_files
  imges=dialog_pickfile(/read,/multiple_files,filter='*.tif',title='please choose your images',path='C:\Users\BDQS\Desktop\zz');读取影像文件路径
  n= N_ELEMENTS(imges);打开影像的个数
  FOR i=0,n-1 do begin;对每个影像，读取指定坐标下的DN值
    envi_open_data_file,imges(i),/IMAGINE,r_fid=fid;
    ENVI_FILE_QUERY, fid, dims=dims, nb=nb ,nl=nl,ns=ns,FNAME=fname;读取影像基本信息，获取行列数
     for curBand =0,nb-1 do begin
      xmap=84.4
      ymap=43.266667   
      ENVI_CONVERT_FILE_COORDINATES,fid,xf,yf,xmap,ymap
      yf=nl-round(yf)
      xf=round(xf)-1
      dims=[-1,xf,xf,yf,yf]
      pointArray(curBand).fname=fname
      pointArray(curBand).data = ENVI_GET_DATA(fid=fid, dims=dims, pos=curBand)
     endfor     
  ENDFOR
  outfile='E:\zz.txt'
  openw,lun,outfile,/get_lun,width=9999999
  printf,lun,pointArray,format='(17a)'
  free_lun,lun
  print,'completed

end