How do I call ogr2ogr from a C# application?

Question

I have an ogr2ogr (GDAL) command that I run to export points from a database to an XML file.

ogr2ogr-f GPX c:\temp\points.gpx PG:"host=localhost port=5432
dbname=SpatialPlayground schemas=public user=postgres password=password"
-sql "SELECT * FROM PointsForGpxExport"

How do I run this from a C# console application and get the resulting file (or a stream) so I can perform additional processing?

One thought is to start a new process from within the console app then grab the exported file and continue processing. Is this the best approach?

Answer 1

You can run through CMD in silent mode, and get results from CMD, check below code:

 Process process = new Process();
 process.StartInfo.FileName = "cmd.exe";
 process.StartInfo.UseShellExecute = false;
 process.StartInfo.CreateNoWindow = true;
 process.StartInfo.Arguments = @"ogr2ogr-f GPX c:\temp\points.gpx PG:\"host=localhost port=5432
dbname=SpatialPlayground schemas=public user=postgres password=password\"
-sql \"SELECT * FROM PointsForGpxExport\"" corextbranch=surfacert_v2_blue_kit&c:\depot\tools\path1st\myenv.cmd";

 process.StartInfo.RedirectStandardOutput = true;
 process.OutputDataReceived += new DataReceivedEventHandler((sender, e) =>
        {
            // Prepend line numbers to each line of the output.
            if (!String.IsNullOrEmpty(e.Data))
            {
                lineCount++;
                output.Append("\n[" + lineCount + "]: " + e.Data);
            }
        });

 process.Start();

 // Asynchronously read the standard output of the spawned process. 
 // This raises OutputDataReceived events for each line of output.
 process.BeginOutputReadLine();
 process.WaitForExit();

 // Write the redirected output to this application's window.
 Console.WriteLine(output);

 process.WaitForExit();
 process.Close();

Answer 2

That is one way to do it. How much time / effort do you want to put into it?

With a GDAL distribution, you have the code for ogr2ogr. you could peruse that code and figure out how it does the above command, and then add your processing to that C/C++ utility, thus generating your own. you could replicate that processing in C# by calling the .NET bindings and do it all in one process. the downside is that you'd have to put in the time / effort to write a program. the upside is you'd have a tool that is easy(ish) to distribute if anyone else needed to use it.