This chapter is from the book
This chapter is from the book
This chapter is from the book
Workshop
The Workshop is designed to help you review what you've learned in this hour and to point you ahead to the material that will be covered in future hours.
Quiz
You need to return a value between 0 and 20. What data type should return?
Byte
You need to alter the variables being passed to your method. How do you declare them?
ByRef in Visual Basic. Ref in C#
What return type would you use when declaring a method that lets a client application know if a given pH is Acid, Base, or Neutral?
You would use an Enumeration (possibly called pH) and give it Acid, Base, and Neutral as possible values.
What do you place after the return statement if you are trying to return the following array of integers: myArray(3)?
You would return myArray.
You have a class called myClient of type Client and it contains two public attributes. What do you declare as your return type?
Client
In Question 5, what do you place after the return statement?
myClient
Exercises
Try experimenting with the different data types that you learned about in this hour. Write methods that accept different methods as parameters as well as those that return them. Do as many as it takes to make you feel comfortable with passing data back and forth between your XML Web service and client applications.
#Region "Simple Data Types"
'Returning a String
<WebMethod()> Public Function StringReturn() As String
Return "This is a string"
End Function
'Return a Byte (0 to 255)
<WebMethod()> Public Function ByteReturn() As Byte
Return 222
End Function
'Return Boolean (true or false)
<WebMethod()> Public Function BoolReturn() As Boolean
Return True
End Function
'Return Short or Int16
<WebMethod()> Public Function ShortReturn() As Short
Return 23344
End Function
'Return Integer or Int32
<WebMethod()> Public Function IntReturn() As Integer
Return -23343444
End Function
'Return Long or Int64
<WebMethod()> Public Function LongReturn() As Long
Return 23344444444444444
End Function
'Return Single
<WebMethod()> Public Function SingleReturn() As Single
Return 233400000000000
End Function
'Return Single
<WebMethod()> Public Function DoubleReturn() As Double
Return 3444344400000000000
End Function
#End Region
#Region "Returning Enums"
'Declaring an Enum
Public Enum Color
Red = 1
Blue = 2
Green = 3
End Enum
'Returning an Enum
<WebMethod()> Public Function EnumReturn() As Color
Return Color.Red
End Function
#End Region
#Region "Returning Arrays"
'Returning an Array
<WebMethod()> Public Function ArrayReturn() As Integer()
Dim a(4) As Integer
Dim i As Integer
For i = 0 To 4
a(i) = i + 1
Next
Return a
End Function
#End Region
#Region "Returning Classes"
'Declaring a Class
Public Class Person
Public Name As String
Public ID As Integer
End Class
'Returning a Class
<WebMethod()> Public Function ClassReturn() As Person
Dim oPerson As New Person()
oPerson.Name = "Jim Smith"
oPerson.ID = 5
Return oPerson
End Function
'Returning an Array of Classes
<WebMethod()> Public Function ClassesReturn() As Person()
Dim oPerson(2) As Person
oPerson(0) = New Person()
oPerson(0).Name = "Jim Smith"
oPerson(0).ID = 1
oPerson(1) = New Person()
oPerson(1).Name = "Edgar Smith"
oPerson(1).ID = 2
oPerson(2) = New Person()
oPerson(2).Name = "Mary Smith"
oPerson(2).ID = 3
Return oPerson
End Function
#End Region
#Region "Params"
'Accepting a String as a param
<WebMethod()> Public Function ParamStringReturn( _
ByVal sWord1 As String, _
ByVal sWord2 As String) As String
Return sWord1 & " and " & sWord2
End Function
'Accepting a Long as a param
<WebMethod()> Public Function ParamLongReturn( _
ByVal iNum1 As Long, _
ByVal iNum2 As Long) As Long
Return iNum2 - iNum1
End Function
'New Enum
Public Enum Champion
Corum = 1
Renark = 2
Urlich = 3
Hawkmoon = 4
End Enum
'Accepting a Enum as a Parameter
<WebMethod()> Public Function ParamEnumReturn( _
ByVal enumName As Champion) As champion
Return enumName
End Function
'Accepting an Array as a Param
<WebMethod()> Public Function ParamArrayReturn( _
ByVal iName() As Integer) As Integer
Return UBound(iName)
End Function
#End Region
#Region "ByRefParams"
'Accepting Integer by Reference
<WebMethod()> Public Function RefReturnReturn( _
ByRef iVal As Integer) As Integer
Dim iOld As Integer
iOld = iVal
iVal = iVal - 1
Return iOld
End Function
'Accepting Classes by Reference
<WebMethod()> Public Sub RefClassReturn( _
ByRef oPers As Person)
oPers.ID = oPers.ID - 1
oPers.Name = "Hi " & oPers.Name
End Sub
#End Region