I have previously asked this question on stack overflow, and am now asking this more specialized audience.
I'm wondering why the GDAL C# library (v2.3.3) call to Gdal.wrapper_GDALBuildVRT_names(...) does not produce a physical destination VRT file.
When I issue the equivalent command in the OSGeo4W shell (to combine the 0000a013.gn1 and 0000b013.gn1 files), a VRT file is written to the supplied destination path (C:\Temp\z7_x43_y43.vrt):
gdalbuildvrt C:\Temp\z7_x43_y43.vrt F:\gnc\1\0000a013.gn1 F:\gnc\1\0000b013.gn1
However, when I issue the command in C#, no VRT file is written to the supplied destination path (I've made sure the folder exists and that the file isn't already there):
GdalConfiguration.ConfigureGdal();
var vrtFile = @"C:\Temp\z7_x43_y43.vrt";
var aeroFiles = new List<string>();
aeroFiles.Add(@"F:\gnc\1\0000a013.gn1");
aeroFiles.Add(@"F:\gnc\1\0000b013.gn1");
var vrtOptions = new GDALBuildVRTOptions(new [] { "-overwrite" });
var vrt = Gdal.wrapper_GDALBuildVRT_names(vrtFile, aeroFiles.ToArray(), vrtOptions, null, null);
The *.gn1 files are NITF, WGS84, degree unit files that work fine in other respects (e.g., the OSGeo4W command processes them perfectly).
The resulting vrt instance is correct - I can use it as a Dataset in other parts of my code, and can even cut PNG tiles from it doing something like this (pngFile and translateOptions are defined elsewhere):
Gdal.wrapper_GDALTranslate(pngFile, vrt, new GDALTranslateOptions(translateOptions.ToArray()), null, null);
But why is no VRT file ever written to disk? We have to supply a destination path (vrtFile), so doesn't that imply a destination file will be written?
