In ActiveReports, you can use an expression to set the value of a control in the report, or set conditions under which certain styles apply. You can set Microsoft Visual Basic® .NET in expressions through,
All expressions begin with an equal sign (=). Even the expression for a field value for a TextBox is set as follows:
=Fields!LastName.Value
You can build expressions quickly using the Expression Editor dialog. This dialog allows you to choose from a number of fields available to the report as well as to a particular property. You can access the Expression Editor by selecting nearly any property of a control and choosing <Expression...> from the dropdown list.
There are the following types of fields available in the Expression Editor:
The Expression Editor dialog is composed of two panes, Fields and Expression.
The expression appears as the property value in the properties grid.
In the raw form, your data may not be ideally suited for display in a report. You can customize it and bring it into shape using expressions. Following are some examples of how expressions are set in different scenarios.
You can concatenate fields with strings and with other fields. For e.g., use the following expression to get a result like Customer Name: Bossert, Lewis.
="Customer Name: " & Fields!LastName.Value & "," & Fields!FirstName.Value
You can use expressions in properties like Color, Font, Border etc. on specific field values based on a condition, to highlight a part of data. The formula for conditional formatting is:
=iif( Fields!YourFieldName.Value operator "Value to compare", "If condition is met, use this value.", "If not, use this one.")
For e.g., if you enter the following expression in the Font > FontWeight property of a textbox that displays names of people, you get the name "Denise" in bold.
=iif(Fields!FirstName.Value = "Denise", "Bold", "Normal")
You can use a number of aggregate and other functions in your expressions. ActiveReports includes a range of functions, including running value, population standard variance, standard deviation, count, minimum and maximum. For e.g., use the following expression to get a count of employees.
=Count(Fields!EmployeeID.Value, Nothing)
As you design the report, the full text of an expression can get very long. ActiveReports makes expressions easier to read by shortening them.
When an expression is in the form:
=Fields!<FieldName>.Value
On the design surface, you see this text inside that TextBox:
=[<FieldName>]
Doubleclick the TextBox to view the full expression in edit mode.
For aggregates too, when the Expression value is:
=<Aggregate>(Fields!<FieldName>.Value)
On the design surface, you see this text inside the TextBox:
=<Aggregate>([<FieldName>])
This shortened expression value is only a visual change to allow you to see the field name easily. It shows up in both the TextBox on the design surface as well as any dropdown boxes inside the dialogs.
Besides the shorthand for field names, you can also type shorthand like [@Param] for parameters and [&Value] for Globals such as [&PageNumber] on the design surface. Please note that you cannot use shorthand in the Expression Editor.
Common Values are run time values available to every property in every report. You can directly drag and drop these common values from the Report Explorer onto the design surface or add and modify the values from the Expression Editor. Following is a list of the values that you can see under the Common Values node in the Report Explorer and in the Expression Editor.
Value  Description  Expression 

Page N of M  Gets both the current page and the total number of pages in the report.  ="Page " & Globals!PageNumber & " of" & Globals!TotalPages 
Page N of M (Section)  Gets both the current page and the total number of pages in the report section.  ="Page " & Globals!PageNumberInSection & " of " & Globals!TotalPagesInSection 
Page N of M (Cumulative)  Gets both the current page and the total number of cumulative pages in a report.  ="Page " & Globals!CumulativePageNumber & " of " & Globals!CumulativeTotalPages 
Current Date and Time  Gets the date and time when the report began to run.  =Globals!ExecutionTime 
User ID  Gets the machine name/user name of the current user.  =User!UserID 
Page Number  Gets the current page number in the report.  =Globals!PageNumber 
Page Number (Section)  Gets the current page number in the report section.  =Globals!PageNumberInSection 
Total Pages  Gets the total number of pages in the report.  =Globals!TotalPages 
Total Pages (Section)  Gets the total number of pages in the report section.  =Globals!TotalPagesInSection 
Cumulative Page Number  Gets the current cumulative page number.  =Globals!CumulativePageNumber 
Cumulative Total Pages  Gets the total number of cumulative pages in the report.  =Globals!CumulativeTotalPages 
Report Folder  Gets the name of the folder containing the report.  =Globals!ReportFolder 
Report Name  Gets the name of the report.  =Globals!ReportName 
User Language  Gets the language settings of the current user.  =User!Language 
You can use a function in an expression to perform actions on data in data regions, groups and datasets. You can access these functions in the Expression Editor dialog. In any property that accepts expressions, you can drop down the property and select <Expression...> to open the dialog.
Within the Expression Editor dialog, there is a tree view of Fields. Expand the Common Functions node to view the available functions. The following tables contain details about each of the functions included in ActiveReports for use in property expressions.
Date & Time
These are all methods from the DateAndTime class in Visual Basic. Please see the msdn DateAndTime Class topic for information on overloads for each method.
These are all the available aggregate functions:
Function  Description  Syntax and Example 

DateAdd  Returns a date and time value that is the result of adding the interval to the date and time field of the specified unit. 
DateAdd(<DateInterval>,<Number>,<DateTime>) =DateAdd("d", 5, Fields!SaleDate.Value); =DateAdd(DateInterval.Day, 5, Fields!SaleDate.Value) 
DateDiff  Returns the difference between the start date and time and end date and time of the specified unit. 
DateDiff(<DateInterval>,<DateTime1>,<DateTime2>[,<DayOfWeek>[,WeekOfYear]])) =DateDiff("yyyy"), Fields!SaleDate.Value,"1/1/2015");=DateDiff(DateInterval.Year,Fields!SaleDate.Value,"1/1/2015") 
DatePart  Returns the Integer value that represents the specified part of the given date. 
DatePart(<DateInterval>,<DateTime1>[,<FirstDayOfWeek>[,FirstWeekOfYear]])) =DatePart("m", Fields!SaleDate.Value) 
DateSerial  Returns a Date value that represents a specified year, month, and a day, with the time information set to midnight (00:00:00). 
DateSerial(<Year Number>,<Month Number>,<Day Number>) =DateSerial(DatePart("yyyy", Fields!SaleDate.Value)10, DatePart("m", Fields!SaleDate.Value)+5, DatePart("d", Fields!SaleDate.Value)1) 
DateString  Returns the String value that represents the current date in your system. 
DateString() =DateString() 
DateValue  Returns a Date value that contains the information on date represented by a string, with the time set to midnight (00:00:00). 
DateValue(<StringDate>) =DateValue("December 12, 2015") 
Now  Returns the current date and time in your system. 
Now() =Now() 
Today  Returns a Date value that contains the current date in your system. 
Today() =Today() 
Day  Returns an Integer value from 1 through 31 that represents the day of the month. 
Day(<DateTime>) =Day(Fields!SaleDate.Value) 
Hour  Returns an Integer value from 0 through 23 that represents the hour of the day. 
Hour(<DateTime>) =Hour(Fields!SaleDate.Value) 
Minute  Returns an Integer value from 0 through 59 that represents the minute of the hour. 
Minute(<DateTime>) =Minute(Fields!SaleDate.Value) 
Month  Returns an Integer value from 0 through 12 that represents the month of the year. 
Month(<DateTime>) =Month(Fields!SaleDate.Value) 
MonthName  Returns the name of the month specified in the date as a String. 
MonthName(<Month Number>[,<Abbreviate>]) =MonthName(Fields!SaleDate.Value) 
Second  Returns an Integer value from 0 through 59 that represents the second of the minute. 
Second(<DateTime>) =Second(Fields!SaleDate.Value) 
TimeSerial  Returns a Date value that represents a specified hour, minute, and second, with the date information set relative to January 1 of the year 0001. 
TimeSerial(<Hour Number>, <Minute Number>, <Second Number>) =TimeSerial(DatePart("h", Fields!SaleDate.Value), DatePart("n", Fields!SaleDate.Value), DatePart("s", Fields!SalesDate.Value)) 
TimeValue  Returns a Date value that contains the information on time represented by a string, with the date set to January 1 of the year 0001. 
TimeValue(<StringTime>) =TimeValue("15:25:45"); TimeValue(Fields!SaleDate.Value) 
TimeOfDay  Returns a Date value containing the current time of day in your system. 
TimeOfDay() =TimeOfDay() 
Timer  Returns a Double value that represents the number of seconds elapsed since midnight. 
Timer() =Timer() 
TimeString  Returns the String value that represents the current time of day in your system. 
TimeString() =TimeString() 
Weekday  Returns an Integer value that contains a number representing the day of the week. 
Weekday(<DateTime[,<DayOfWeek>]) =Weekday(Fields!SaleDate.Value,0) 
WeekdayName  Returns a String value that contains the name of the specified weekday. 
WeekdayName(<WeekDay>[,<Abbreviate[, <FirstDayOfWeek>]]) =WeekdayName(3, True, 0); =WeekDayName("w", Fields!SaleDate.Value), True, 0) 
Year  Returns an Integer value from 1 through 9999 representing the year. 
Year(<DateTime>) =Year(Fields!SaleDate.Value) 
Quarter  Returns an Integer value from 1 through 4 representing the quarter number. 
Quarter(<DateTime>) =Quarter(Fields!SaleDate.Value) 
QuarterName  Returns a string value representing the quarter name. 
QuarterName(<DateTime>) =QuarterName(Fields!SaleDate.Value) 
Math
These are all methods and fields from the System.Math class. Please see the msdn Math Class topic for information on overloads for each method.
Function  Description  Syntax and Example 

Abs  Returns the absolute or positive value of a singleprecision floatingpoint number. 
Abs(<Number>) =Abs(5.5);=Abs(Fields!YearlyIncome.Value80000) 
Acos  Returns the angle whose cosine is the specified number. 
Acos(<Number>) =Acos(.5); =Acos(Fields!Angle.Value) 
Asin  Returns the angle whose sine is the specified number 
Asin(<Number>) =Asin(.5); =Asin(Fields!Angle.Value) 
Atan  Returns the angle whose tangent is the specified number. 
Atan(<Number>) =Atan(.5); =Atan(Fields!Angle.Value) 
Atan2  Returns the angle whose tangent is the quotient of two specifed numbers. 
Atan2(<Number1>,<Number2>) =Atan2(3,7); =Atan2(Fields!CoordinateY.Value,Fields!CoordinateX.Value) 
BigMul  Returns the multiplication of two 32bit numbers. 
BigMul(<Number1>,<Number2>) =BigMul(4294967295,2147483647); =BigMul(Fields!Int32Value.Value, Fields!Int32Value.Value) 
Ceiling  Returns the smallest integer greater than or equal to the specified doubleprecision floatingpoint number. 
Ceiling(<Number>) =Ceiling(98.4331); =Ceiling(Fields!AnnualSales.Value /6) 
Cos  Returns the smallest integer greater than or equal to the specifed doubleprecision floatingpoint number. 
Cos(<Number>) =Cos(60) 
Cosh  Returns the hyperbolic cosine of the specified angle. 
Cosh(<Number>) =Cosh(60) 
E  Returns the value of E, which is 2.71828182845905. 
E =E*2 
Exp  Returns e raised to the specified ^, where is Euler s number. It is the inverse of the Log function. 
Exp(<Number>) =Exp(3); =Exp(Fields!IntegerCounter.Value) 
Fix  Returns the integer portion of a number. 
Fix(<Number>) =Fix(7.15); =Fix(Fields!AnnualSales.Value /5) 
Floor  Returns the longest integer less than or equal to the specified doubleprecision floatingpoint number. 
Floor(<Number>) =Floor(4.67); =Floor(Fields!AnnualSales.Value/ 12) 
IEEERemainder  Returns the remainder after division of one number by another according to IEEE satndards. 
IEEERemainder(<Number1>,<Number2>) =IEEERemainder(9,8) 
Log  Returns the logarithm of the specified number. 
Log(<Number>) =Log(20.5); =Log(Fields!NunberValue.Value) 
Log10  Returns the logarithm of the specified number to the base 10. 
Log10(<Number>) =Log10(20.5); =Log10(Fields!NumberValue.Value) 
Max  Returns the maximum nonnull value from the specified expression. 
Max(<Value>) =Max(Fields!OrderTotal.Value) 
Min  Returns the minimum nonnull value from the specified expression. 
Min(<Value>) =Min(Fields!OrderTotal.Value) 
PI  Returns the value of PI, which is 3.14159265358979. 
PI =2 * PI * Fields!Radius.Value 
Pow  Returns one number raised to the ^ of another number. 
Pow(<Number1,<Number2>) =Pow(Fields!Quantity.Value, 2) 
Round  Returns the roundoff of a decimal number to the nearest integer or to the nearest decimal number up to the specified digits. 
Round(<Number>) =Round(12.456); =Round(Fields!AnnualSales.Value / 12.3) 
Sign  Returns a value indicating the sign of an 8bit signed integer. 
Sign(<Number>) =Sign(Fields!AnnualSales.Value60000) 
Sin  Returns the sine of the specified number. 
Sin(<Number>) =Sin(60) 
Sinh  Returns the hyperbolic sine of the specified angle. 
Sinh(<Number>) =Sinh(60) 
Sqrt  Returns the square root of the specified number. 
Sqrt(<Number>) =Sqrt(121) 
Tan  Returns the tangent of the specified number. 
Tan(<Number>) =Tan(60) 
Tanh  Returns the hyperbolic tangent of the specified angle. 
Tanh(<Number>) =Tanh(60) 
Inspection
These are all methods from the DateAndTime class in Visual Basic. Please see the msdn DateAndTime Class topic for information on overloads for each method.
Function  Description  Syntax and Example 

IsArray  Returns True if the expression can be evaluated as an array. 
IsArray(<Expression>) =IsArray(Parameters!Initials.Value) 
IsDate  Returns True if the expression represents a valid Date value. 
IsDate(<Expression>) =IsDate(Fields!BirthDate.Value); =IsDate("31/12/2010") 
IsDBNull  Returns True if the expression evaluates to a null. 
IsDBNull(<Expression>) =IsDBNull(Fields!MonthlySales.Value) 
IsError  Returns True if the expression evaluates to an error. 
IsError(<Expression>) =IsError(Fields!AnnualSales.Value = 80000) 
Isnothing  Returns True if the expression evaluates to nothing. 
IsNothing(<Expression>) =IsNothing(Fields!MiddleInitial.Value) 
IsNumeric  Returns True if the expression can be evaluated as a number. 
IsNumeric(<Expression>) =IsNumeric(Fields!AnnualSales.Value) 
ProgramFlow
These are all methods from the Interaction class in Visual Basic. Please see the msdn Interaction Class topic for more information.
Function  Description  Syntax and Example 

Choose  Returns a value from a list of arguments. 
Choose(<Index>,<Value>[, <Value2>,...[, <Value N>]]) =Choose(3, "10", "15", "20", "25") 
IIF  Returns the value if the expression evaluates to True, and the second value if the expression evaluates to False. 
IIF(<Condition>, <TruePart>, <FalsePart>) =IIF(Fields!AnnualSales.Value >= 80000, "Above Average", "Below Average") 
Partition  Returns a string (in the form x : y) that represents the calculated range based on the specified interval containing the specified number. 
Partition(<Value>, <Start>, <End>, <Interval>) =Partition(1999, 1980, 2000, 10) 
Switch  Returns the value of the first expression that evaluates to True among a list of expressions. 
Switch(<Condition1>, <Value1>[, <Condition2>, <Value2>,...[,<ConditionN>, <ValueN>]]) =Switch(Fields!FirstName.Value = "Abraham", "Adria", Fields!FirstName.Value = "Charelotte", "Cherrie") 
Aggregate
You can use aggregate functions within report control value expressions to accrue data. ActiveReports supports aggregate functions from RDLX 2005, plus some proprietary extended set of functions. For all of the functions, you can add an optional <Scope> parameter.
These are all the available aggregate functions:
Function  Description  Syntax and Example 

AggregateIf  Decides whether to calculate a custom aggregate from the data provider of the values returned by the expression based on a Boolean expression. 
AggregateIf(<Condition>, <AggregateFunction>, <AggregateArguments>) =AggregateIf(Fields!Discontinued.Value=True, Sum, Fields!InStock.Value) 
Avg  Calculates the average of the nonnull values returned by the expression. 
Avg(<Values>) =Avg(Fields!Cost.Value, Nothing) 
Count  Calculates the number of nonnull values returned by the expression. 
Count(<Values>) =Count(Fields!EmployeeID.Value, Nothing) 
CountDistinct  Calculates the number of nonrepeated values returned by the expression. 
CountDistinct(<Values>) =CountDistinct(Fields!ManagerID.Value, "Department") 
CountRows  Calculates the number of rows in the scope returned by the expression. 
CountRows() =CountRows("Department") 
CrossAggregate  Calculates the specified function with the specified expression as an argument in the cross of the specified row and column. 
CrossAggregate(<Expression>, <FunctionName>, <ColumnGroupName>, <RowGroupName>) =CrossAggregate(Fields!Count.Value, "Sum", "MonthGroup", "ProductGroup") 
CumulativeTotal  Calculates the sum of pagelevel aggregates returned by the expression for current and previous pages. 
CumulativeTotal(<Expression>, <Aggregate>) =CumulativeTotal(Fields!OrderID.Value, Count) 
DistinctSum  Calculates the sum of the values returned by an expression using only the rows when the value of another expression is not repeated. 
DistinctSum(<Values>, <Value>) =DistinctSum(Fields!OrderID.Value, Fields!OrderFreight.Value, "Order") 
First  Shows the first value returned by the expression. 
First(<Values>) =First(Fields!ProductNumber.Value, "Category") 
Last  Shows the last value returned by the expression. 
Last(<Values>) =Last(Fields!ProductNumber.Value, "Category") 
Max  Shows the largest nonnull value returned by the expression. 
Max(<Values>) =Max(Fields!OrderTotal.Value, "Year") 
Median  Shows the value that is the midpoint of the values returned by the expression. Half of the values returned will be above this value and half will be below it. 
Median(<Values>) =Median(Fields!OrderTotal.Value) 
Min  Shows the smallest nonnull value returned by the expression 
Min(<Values>) =Min(Fields!OrderTotal.Value) 
Mode  Shows the value that appears most frequently in the values returned by the expression. 
Mode(<Values>) =Mode(Fields!OrderTotal.Value) 
RunningValue  Shows a running aggregate of values returned by the expression (Takes one of the other aggregate functions as a parameter), 
RunningValue(<Values>, <AggregateFunction>) =RunningValue(Fields!Cost.Value, Sum, Nothing) 
StDev  Calculates the dispersion (standard deviation) of all nonnull values returned by the expression. 
StDev(<Values>) =StDev(Fields!LineTotal.Value, "Order") 
StDevP  Calculates the population dispersion (population standard deviation) of all nonnull values returned by the expression. 
StDevP(<Values>) =StDevP(Fields!LineTotal.Value, "Order") 
Sum  Calculates the sum of the values returned by the expression. 
Sum(<Values>) =Sum(Fields!LineTotal.Value, "Order") 
Var  Calculates the variance (standard deviation squared) of all nonnull values returned by the expression. 
Var(<Values>) =Var(Fields!LineTotal.Value, "Order") 
VarP  Calculates the population variance (population standard deviation squared) of all nonnull values returned by the expression. 
VarP(<Values>) =VarP(Fields!LineTotal.Value, "Order") 
Conversion
These are all methods from the Convert class in the .NET Framework. Please see the msdn Convert Class topic for more information.
Function  Description  Syntax and Example 

ToBoolean  Converts the specified value to Boolean. 
ToBoolean(<Value> =ToBoolean(Fields!HouseOwnerFlag.Value) 
ToByte  Converts the specified value to Byte. 
ToByte(<Value>) =ToByte(Fields!ProductNumber.Value) 
ToDateTime  Converts the specified value to a Date and Time value. 
ToDateTime(<Value>) =ToDateTime(Fields!SaleDate.Value); =ToDateTime("1 January, 2017") 
ToDouble  Converts the specified value to Double. 
ToDouble(<Value>) =ToDouble(Fields!AnnualSales.Value); =ToDouble(535.85 * .2691 * 67483) 
ToInt16  Converts the specified value to a 16bit signed Integer. 
ToInt16(<Value>) =ToInt16(Fields!AnnualSales.Value); =ToInt16(535.85) 
ToInt32  Converts the specified value to a 32bit signed Integer. 
ToInt32(<Value>) =ToInt32(Fields!AnnualSales.Value) 
ToInt64  Converts the specified value to a 64bit signed Integer. 
ToInt64(<Value>) =ToInt64(Fields!AnnualSales.Value) 
ToSingle  Converts the specified value to a singleprecision floatingpoint number. 
ToSingle(<Value>) =ToSingle(Fields!AnnualSales.Value); =ToSingle(15.857692134) 
ToUInt16  Converts the specified value to a 16bit unsigned Integer. 
ToUInt16(<Value>) =ToUInt16(Fields!AnnualSales.Value) 
ToUInt32  Converts the specified value to a 32bit unsigned Integer. 
ToUInt32(<Value>) =ToUInt32(Fields!AnnualSales.Value) 
ToUInt64  Converts the specified value to a 64bit unsigned Integer. 
ToUInt64(<Value>) =ToUInt64(Fields!AnnualSales.Value) 
Miscelleneous
ActiveReports also offers several functions which do not aggregate data, but which you can use with an IIf function to help determine which data to display or how to display it.
The first four are miscellaneous functions from the RDLX 2005 specifications. GetFields is a proprietary function to extend RDLX specifications.
Function  Description  Syntax and Example  

InScope  Determines whether the current value is in the indicated scope.  InScope(<Scope>) =InScope("Order") 

Level  Returns the level of the current value in a recursive hierarchy.  Level() =Level() 

Previous  Returns the previous value within the indicated scope.  Previous(<Value>) =Previous(Fields!OrderID.Value) 

RowNumber  Shows a running count of all the rows in the scope returned by the expression.  RowNumber() =RowNumber() 

GetFields 
Returns an IDictionary<string,Field> object that contains the current contents of the Fields collection. Only valid when used within a data region. This function makes it easier to write code that deals with complex conditionals. To write the equivalent function without GetFields() would require passing each of the queried field values into the method which could be prohibitive when dealing with many fields. 
GetFields() =Code.DisplayAccountID(GetFields())


Lookup  Returns the first matching value for the specified name from the dataset with pairs of name and value. For more information, see Report Builder Functions  Lookup Function. 
Lookup(<SourceExpression>, <DestinationExpression>, <ResultExpression>, <LookupDataset>) =Lookup(Fields!ProductID.Value, Fields!ProductID.Value, Fields!Quantity.Value, "DataSet2") 

LookupSet  Returns multiple row values from a specified dataset and can be used for the 1tomany relationship. For more information, see Report Builder Functions  LookupSet Function. 
LookupSet(source_expression, destination_expression, result_expression, dataset) =LookupSet(Fields!CategoryID.Value, Fields!CategoryID.Value, Fields!UnitsInStock.Value, "Products") 

MapPoint  Allows displaying simple data directly on the Map as a map Point Layer. 
MapPoint(<Latitude>, <Longitude>) =MapPoint(Fields!Latitude.Value, Fields!Longitude.Value) 

GroupIndex  Returns the index of the element in the current group.  =GroupIndex()  
GroupIndex (with scope)  Returns the index of the element in the specified group.  =GroupIndex(<Group>) 
Scope
All functions have a Scope parameter which determines the grouping, data region, or dataset to be considered when calculating the aggregate or other function. Within a data region, the Scope parameter's default value is the innermost grouping to which the report control belongs. Alternately, you can specify the name of another grouping, dataset, or data region, or you can specify Nothing, which sets it to the outermost data region to which the report control belongs.
The Scope parameter must be a data region, grouping, or dataset that directly or indirectly contains the report control using the function in its expression. If the report control is outside of a data region, the Scope parameter refers to a dataset. If there is only one dataset in the report, you can omit the Scope parameter. If there are multiple datasets, you must specify which one to use to avoid ambiguity.
Note: You cannot set the Scope parameter to Nothing outside of a data region.