Le lundi 12 octobre 2015 11:12:37, Jhon Chin a écrit : > Thks a lot!!! Even, so I should avoid using Field name that counts more > than 10 bytes, and there is no workaround ?
Yes. Do you really need shapefile though ? If not, you could use more modern formats like GeoPackage or Spatialite that don't suffer from shapefile limitations : http://www.gdal.org/drv_geopackage.html , http://www.gdal.org/drv_sqlite.html Potential idea if you need to stick with shapefiles: according to Google Translate this field name is translated in to English as Normalized Difference Vegetation Index, and in English it is often just abbreviated with its well- known acronym NDVI. Perhaps there's the equivalent of acronyms in Chinese ? Even > > your sincerely, > > Jhon Chin > > On Mon, Oct 12, 2015 at 5:01 PM, Even Rouault <even.roua...@spatialys.com> > > wrote: > > Jhon Chin, > > > > > Hi, everybody: > > > > > > add one more question : > > > > > > the field name can be read 10 ascii characters, the last characters > > > would be trimmed, > > > > Not necessarily 10 ascii characters, but 10 bytes. The number of > > characters that can fit on 10 bytes depends on the encoding. 1 ASCII > > character = 1 byte. > > But for non ASCII characters such as Chinese characters, one character > > fits on > > several bytes. > > > > > is there anyone encounter this problem? > > > > Yes, everybody ! This is a limitation of the > 30 year old DBF format. > > > > I've tried the following Python script that creates a shapefile with the > > CP936 > > encoding. > > > > {{{ > > # -*- coding: utf-8 -*- > > > > from osgeo import ogr > > > > ds = ogr.GetDriverByName('ESRI > > Shapefile').CreateDataSource('test_cp936.dbf') > > lyr = ds.CreateLayer('test_cp936', options = ['ENCODING=CP936']) > > lyr.CreateField(ogr.FieldDefn("归一化植被指数",ogr.OFTInteger)) > > }}} > > > > It emits a warning about truncation since the field name cannot fit on 10 > > bytes > > once recoded in CP936. > > > > Here's the result: > > > > $ ogrinfo cp936.dbf -al > > INFO: Open of `cp936.dbf' > > > > using driver `ESRI Shapefile' successful. > > > > Layer name: cp936 > > > > Metadata: > > DBF_DATE_LAST_UPDATE=2015-10-12 > > > > Geometry: Line String > > Feature Count: 0 > > Extent: (0.000000, 0.000000) - (0.000000, 0.000000) > > Layer SRS WKT: > > (unknown) > > 归一化植被: Integer (9.0) > > > > So the last 2 characters are lost. > > > > > any help would be appreciated! > > > > > > Jhon Chen > > > > > > On Mon, Oct 12, 2015 at 3:43 PM, Jhon Chin <giantchen2...@gmail.com> > > > > wrote: > > > > Hi, everybody: > > > > > > > > I'm now trying to write polygonized result into an esri shapefile, > > > > and > > > > I > > > > > > tried > > > > > > > > to add some field to the attribute table in the shapefile. But it > > > > corrupted > > > > > > > > when i was trying to create an *ogrfielddefn* instance.The code goes > > > > > > > > like this: > > > > OGRFieldDefn oField("归一化植被指数",OFTInteger); > > > > if(poLayer->CreateField(&oField) != OGRERR_NONE) > > > > { > > > > > > > > printf("create 归一化植被指数 failed!"); > > > > exit(1); > > > > > > > > } > > > > -- > > Spatialys - Geospatial professional services > > http://www.spatialys.com -- Spatialys - Geospatial professional services http://www.spatialys.com _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
