Providing environment variables to package execution using PackageInfo class

I've been looking around the web for days now and I haven't been able to find a single example on how to pass environment variables to a package.

We're using the new ssis project development to deploy packages to the SSIS catalog so I need to use the Microsoft.SQLServer.Management.IntegrationServices assembly to access packages. I found an excelent example on how to run it here. The problem is, every one of our packages (more than 100) have around 7 parameters they need to execute and I can't provide values for them! Not even hard-coded values. It's driving me insane. I keep getting the Reference not made to an instance of an object error because apparently the PackageInfo class is static. For this project, there are different environments configured in the SSIS Catalog that I need to map to the variables of the packages.

I've tried setting the parameters like they set the SYNCHRONIZED parameter on the example, but to no effect. For some variables I get an error saying that I don't have sufficient permissions to access them, which makes sense but I can't figure out how (or where) to provide the needed credentials (It might be good to mention that we've used windows authentication until now, configuring permissions to the domain users that are working on the project).

I am stuck. Has anybody done this? I know its really easy to set the variables the old way (Dts.Runtime assembly) but this new assembly is poorly documented and very few examples are available on the web (none of which touch the subject of environment variables). Any help would be gratefully accepted!

[EDIT]

This is the code I'm using:

SqlConnection connection = new SqlConnection(@"Data Source=my-ssis-server;Initial Catalog=MyDB;Integrated Security=SSPI;");
IntegrationServices ssis = new IntegrationServices(connection);

//Get handle on package
PackageInfo pk = ssis.Catalogs["SSISDB"].Folders["MyFolder"].Projects["MyProject"].Packages["MyPackage.dtsx"];
var executionParameter = new Collection<PackageInfo.ExecutionValueParameterSet>();

executionParameter.Add(new PackageInfo.ExecutionValueParameterSet
   {
   	   ObjectType = 50,
   	   ParameterName = "SYNCHRONIZED",
   	   ParameterValue = 1
   });

//This throws: The parameter 'MyParam' does not exist or you do not have sufficient permissions.
/*executionParameter.Add   
   (new PackageInfo.ExecutionValueParameterSet
   {
       ObjectType = 50,
       ParameterName = "MyParam",
       ParameterValue = "myvalue"
   });*/

//This throws: Object reference not set to an instance of an object.
pk.Parameters["MyParam"].Set(
   ParameterInfo.ParameterValueType.Literal,
   "MyValue"
);

pk.Alter();

long executionIdentifier = pk.Execute(false, null, executionParameter);

Tags: C#, .NET, SQL Server, SSIS