Using Constants in Expressions (Reporting Services)

A constant consists of literal text or text that has been predefined by a component of Reporting Services. The report processor has access to the predefined constants so that when you include them in an expression, the values they represent are substituted in the expression before it is evaluated.

Literal Text

In an expression, literal text is text that is in double quotation marks. You can also type text directly into a text box without double quotation marks if it is not part of an expression. If the text box value does not begin with an equal sign (=), the text is treated as literal text. The following table shows several examples of literal text in an expression.

Constant	Display text	Expression text
Report run at:	<<Expr>>	="Report run at: " & Globals!ExecutionTime
Adventure Works Cycles	Adventure Works Cycles	Adventure Works Cycles
[Bracketed display text]	\[Bracketed display text\]	[Bracketed display text]

For more information, see Understanding Simple and Complex Expressions (Reporting Services).

RDL Constants

You can use constants defined in Report Definition Language (RDL) in an expression. In the Expression dialog box, constants appear when you create an expression for a report property that only accepts certain valid values, also known as enumerated types. The following table shows two examples.

Property	Description	Values
TextAlign	Valid values for aligning text in a text box.	General, Left, Center, Right
BorderStyle	Valid values for a line added to a report.	Default, None, Dotted, Dashed, Solid, Double, DashDot, DashDotdot

Visual Basic Constants

You can use constants defined in the Visual Basic run-time library in an expression. The following table shows two examples. 

Constant	Description
vbCrLf	The Visual Basic constant for a carriage return followed a new line. For example, the following expression shows the time stamp for report processing and the user on two lines in a single text box: =Globals!ExecutionTime & vbCrLf & User!UserID
DateInterval.Day	The Visual Basic constant that you use to designate the day part of a date time value in a DatePart function call. For example, for the date January 10, 2008, the following function returns the number 10: =DatePart("d",Globals!ExecutionTime)

CLR Constants

You can use constants defined in .NET Framework common language run-time (CLR) classes in an expression. The following table shows an example of a system-defined color.

Constant	Description
MistyRose	When you create an expression for a report property that is based on background color, you can specify a color by name. Valid names are listed in the Expression dialog box.

See Also

Reference

Expression Dialog Box

Expression Examples (Reporting Services)

Concepts

Working with Data Types in Expressions (Reporting Services)

Other Resources

Working with Report Expressions