SSRS report: Is it possible to use a SQL query for setting the AllowBlank property of a parameter?

Actually i want to find out, if it is possible to set the AllowBlank property of a parameter in a SSRS report via SQL query.

I want to do this, because i have in the parameters one which is depending on another parameter.

When the value of the other parameter is "-1" then the value of the dependent parameter shall not be blank.

But just in this case.

Maybe this could be done in the XML with a SQL query like in this example:

<ReportParameter Name="Parameter2"> <DataType>String</DataType> <AllowBlank>SELECT IIF (Parameters!Parameter1.Value = '-1', false, true)</AllowBlank> </ReportParameter>