This is a correct way to assign value to a report parameter. you can also use the ReportSource
Parameters collection, which maps by key to the report's ReportParameters collection. Consider the example in the TypeReportSource Class
If your concerns are regarding working with GUID type, it depends what is the purpose the field. You can work entirely with String or use the approach illustrated in the How to use a Guid as value for report parameter or data source parameter?
If you need further help, please elaborate on the scenario.
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