Dim definition As New ReportDefinition(New FileInfo(strFile))
definition.ConfigurationProvider = New DefaultConfigurationProvider()
For i As Integer = 0 To definition.Report.DataSources.Count - 1
 definition.Report.DataSources(i).ConnectionProperties.ConnectString = DataDynamics.Reports.Expressions.ExpressionInfo.Parse(ConfigurationManager.ConnectionStrings("MyTestConnectionString").ConnectionString, Expressions.ExpressionResultType.String)
Next
Dim _reportRuntime As New ReportRuntime(definition)
For i As Integer = 0 To _reportRuntime.ReportDefinition.Report.DataSources.Count - 1
 _reportRuntime.ReportDefinition.Report.DataSources(i).ConnectionProperties.ConnectString = DataDynamics.Reports.Expressions.ExpressionInfo.Parse(ConfigurationManager.ConnectionStrings("MyTestConnectionString").ConnectionString, Expressions.ExpressionResultType.String)
Next
_reportRuntime.Parameters("TESTPARAMID").CurrentValue = 1
Me.WebReportViewer1.SetReport(_reportRuntime)