Selon Maksim Sestic <[email protected]>: > Hm, that's strange. I'm using Gdal.Open() to fetch WMS graphics, for example: > > Dim ds As Dataset = Gdal.Open("<GDAL_WMS><Service > name="WMS"><Version>1.3.0</Version><ServerUrl>http://wms.agiv.be/inspire/wms/orthobeeldvorming</ServerUrl><CRS>CRS:84</CRS><ImageFormat>image/png</ImageFormat><Transparent>True</Transparent><Layers>RGB</Layers><Styles></Styles></Service><DataWindow><UpperLeftX>3.76302095985856</UpperLeftX><UpperLeftY>50.9987228424621</UpperLeftY><LowerRightX>3.76629196690679</LowerRightX><LowerRightY>50.9968195506639</LowerRightY><SizeX>2439</SizeX><SizeY>2255</SizeY></DataWindow><Projection>EPSG:4326</Projection></GDAL_WMS>", > Access.GA_ReadOnly) > > ...returns requested dataset, which I further save to disk using appropriate > Driver and CreateCopy() method. It works correctly. I hope that above > example does not perform GetCapabilities() at all?
No it shouldn't > > I was thinking about above case, when Gdal.Open(...) actually reads a raster > dataset from WMS. First it creates "grid" of tiles if pixel size is larger > than BlockSizeX/Y. Then it reads tile by tile from server, merging them all > at the end into the final dataset. Downloading each tile would trigger > progress change. Setting BlockSize to i.e. 256x256 pixels (instead of > default 1024x1024) should make it granular enough for progress bars. GDALOpen() will divide into tiles, but will not read them. You need to call CreateCopy() or RasterIO() for that. So : 1) Open() on the XML description is a fast operation that doesn't download anything and doesn't need progress 2) CreateCopy() has a progress callback which will be regularly called. Depending on the output driver, it might not be called for each tile though, but perhaps for each line. > > Regards, > Maksim Sestic > > > -- > View this message in context: > http://osgeo-org.1803224.n2.nabble.com/C-bindings-setting-up-progress-delegate-for-Gdal-Open-tp7146342p7146691.html > Sent from the GDAL - Dev mailing list archive at Nabble.com. > _______________________________________________ > gdal-dev mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/gdal-dev > _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
