Hello,
I have a generic list as follows:
Dim rows As New Generic.List(Of row)
Now I have a row:
Dim myRow As row
I tried to check, further in my code, if the row is nothing:
If myRow Is Nothing Then
....
End If
I get an error:
"Is" requires operand that have reference types but this operand has
the value of Rows.Row"
Any idea what I am doing wrong?
Anyway, this is my row definition and its dependencies:
' Row
Public Structure Row
' -- [Properties] ----
' Cells
Private _Cells As Generic.List(Of Cell)
Public Property Cells() As Generic.List(Of Cell)
Get
Return _Cells
End Get
Set(ByVal Cells As Generic.List(Of Cell))
_Cells = Cells
End Set
End Property ' Cells
' Name
Private _Name As String
Public Property Name() As String
Get
Return _Name
End Get
Set(ByVal Name As String)
_Name = Name
End Set
End Property ' Name
End Structure ' Row
' Cell
Public Structure Cell
' -- [Properties] ----
' Content
Private _Content As Object
Public Property Content() As Object
Get
Return _Content
End Get
Set(ByVal Content As Object)
_Content = Content
End Set
End Property ' Content
' Culture
Private _Culture As CultureInfo
Public Property Culture() As CultureInfo
Get
Return _Culture
End Get
Set(ByVal Culture As CultureInfo)
_Culture = Culture
End Set
End Property ' Culture
End Structure ' Cell
Thanks,
Miguel
16  1741 
Structures are value types, so you can use "= Nothing".
--
David Anton www.tangiblesoftwaresolutions.com
Instant C#: VB to C# converter
Instant VB: C# to VB converter
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"shapper" wrote:
Hello,
I have a generic list as follows:
Dim rows As New Generic.List(Of row)
Now I have a row:
Dim myRow As row
I tried to check, further in my code, if the row is nothing:
If myRow Is Nothing Then
....
End If
I get an error:
"Is" requires operand that have reference types but this operand has
the value of Rows.Row"
Any idea what I am doing wrong?
Anyway, this is my row definition and its dependencies:
' Row
Public Structure Row
' -- [Properties] ----
' Cells
Private _Cells As Generic.List(Of Cell)
Public Property Cells() As Generic.List(Of Cell)
Get
Return _Cells
End Get
Set(ByVal Cells As Generic.List(Of Cell))
_Cells = Cells
End Set
End Property ' Cells
' Name
Private _Name As String
Public Property Name() As String
Get
Return _Name
End Get
Set(ByVal Name As String)
_Name = Name
End Set
End Property ' Name
End Structure ' Row
' Cell
Public Structure Cell
' -- [Properties] ----
' Content
Private _Content As Object
Public Property Content() As Object
Get
Return _Content
End Get
Set(ByVal Content As Object)
_Content = Content
End Set
End Property ' Content
' Culture
Private _Culture As CultureInfo
Public Property Culture() As CultureInfo
Get
Return _Culture
End Get
Set(ByVal Culture As CultureInfo)
_Culture = Culture
End Set
End Property ' Culture
End Structure ' Cell
Thanks,
Miguel
"shapper" <md*****@gmail. comwrote in message
news:11******** **************@ n33g2000cwc.goo glegroups.com.. .
If myRow Is Nothing Then
If myRow = Nothing Then
Actually, "= Nothing" won't work unless you have overloaded the '=' operator
in your structure.
--
David Anton www.tangiblesoftwaresolutions.com
Instant C#: VB to C# converter
Instant VB: C# to VB converter
Instant C++: C#/VB to C++ converter
Instant Python: C#/VB to Python converter
"shapper" wrote:
Hello,
I have a generic list as follows:
Dim rows As New Generic.List(Of row)
Now I have a row:
Dim myRow As row
I tried to check, further in my code, if the row is nothing:
If myRow Is Nothing Then
....
End If
I get an error:
"Is" requires operand that have reference types but this operand has
the value of Rows.Row"
Any idea what I am doing wrong?
Anyway, this is my row definition and its dependencies:
' Row
Public Structure Row
' -- [Properties] ----
' Cells
Private _Cells As Generic.List(Of Cell)
Public Property Cells() As Generic.List(Of Cell)
Get
Return _Cells
End Get
Set(ByVal Cells As Generic.List(Of Cell))
_Cells = Cells
End Set
End Property ' Cells
' Name
Private _Name As String
Public Property Name() As String
Get
Return _Name
End Get
Set(ByVal Name As String)
_Name = Name
End Set
End Property ' Name
End Structure ' Row
' Cell
Public Structure Cell
' -- [Properties] ----
' Content
Private _Content As Object
Public Property Content() As Object
Get
Return _Content
End Get
Set(ByVal Content As Object)
_Content = Content
End Set
End Property ' Content
' Culture
Private _Culture As CultureInfo
Public Property Culture() As CultureInfo
Get
Return _Culture
End Get
Set(ByVal Culture As CultureInfo)
_Culture = Culture
End Set
End Property ' Culture
End Structure ' Cell
Thanks,
Miguel
On Mar 13, 2:22 pm, "Mark Rae" <m...@markNOSPA Mrae.comwrote:
"shapper" <mdmo...@gmail. comwrote in message
news:11******** **************@ n33g2000cwc.goo glegroups.com.. .
If myRow Is Nothing Then
If myRow = Nothing Then
I have tried that before and it didn't work.
Basically my code is:
Dim myRow As Rows.Row = allRows.Rows.Fi nd(AddressOf
FindRowByName.S earch)
If rBox = Nothing Then ...
I get the error:
Operator '=' is not defined for Rows.Row
Any idea?
Thanks,
Miguel
Even though VB allows the use of "Nothing" with structure types (such as
Int32 for example), it tends to be confusing (and requires overloading the
Equals operator). What you should do instead is have a read only property on
your structure, such as "IsInitialized" , which returns true if the instance
is explicitly initialized or populated.
--
David Anton www.tangiblesoftwaresolutions.com
Instant C#: VB to C# converter
Instant VB: C# to VB converter
Instant C++: C#/VB to C++ converter
Instant Python: C#/VB to Python converter
"shapper" wrote:
Hello,
I have a generic list as follows:
Dim rows As New Generic.List(Of row)
Now I have a row:
Dim myRow As row
I tried to check, further in my code, if the row is nothing:
If myRow Is Nothing Then
....
End If
I get an error:
"Is" requires operand that have reference types but this operand has
the value of Rows.Row"
Any idea what I am doing wrong?
Anyway, this is my row definition and its dependencies:
' Row
Public Structure Row
' -- [Properties] ----
' Cells
Private _Cells As Generic.List(Of Cell)
Public Property Cells() As Generic.List(Of Cell)
Get
Return _Cells
End Get
Set(ByVal Cells As Generic.List(Of Cell))
_Cells = Cells
End Set
End Property ' Cells
' Name
Private _Name As String
Public Property Name() As String
Get
Return _Name
End Get
Set(ByVal Name As String)
_Name = Name
End Set
End Property ' Name
End Structure ' Row
' Cell
Public Structure Cell
' -- [Properties] ----
' Content
Private _Content As Object
Public Property Content() As Object
Get
Return _Content
End Get
Set(ByVal Content As Object)
_Content = Content
End Set
End Property ' Content
' Culture
Private _Culture As CultureInfo
Public Property Culture() As CultureInfo
Get
Return _Culture
End Get
Set(ByVal Culture As CultureInfo)
_Culture = Culture
End Set
End Property ' Culture
End Structure ' Cell
Thanks,
Miguel
On Mar 13, 10:45 am, "shapper" <mdmo...@gmail. comwrote:
On Mar 13, 2:22 pm, "Mark Rae" <m...@markNOSPA Mrae.comwrote:
"shapper" <mdmo...@gmail. comwrote in message
news:11******** **************@ n33g2000cwc.goo glegroups.com.. .
If myRow Is Nothing Then
If myRow = Nothing Then
I have tried that before and it didn't work.
Basically my code is:
Dim myRow As Rows.Row = allRows.Rows.Fi nd(AddressOf
FindRowByName.S earch)
If rBox = Nothing Then ...
I get the error:
Operator '=' is not defined for Rows.Row
Any idea?
Thanks,
Miguel
Here's a question for you: Does your Search method ever return Nothing?
On Mar 13, 3:11 pm, "Mike Hofer" <kchighl...@gma il.comwrote:
On Mar 13, 10:45 am, "shapper" <mdmo...@gmail. comwrote:
On Mar 13, 2:22 pm, "Mark Rae" <m...@markNOSPA Mrae.comwrote:
"shapper" <mdmo...@gmail. comwrote in message
>news:11******* *************** @n33g2000cwc.go oglegroups.com. ..
If myRow Is Nothing Then
If myRow = Nothing Then
I have tried that before and it didn't work.
Basically my code is:
Dim myRow As Rows.Row = allRows.Rows.Fi nd(AddressOf
FindRowByName.S earch)
If rBox = Nothing Then ...
I get the error:
Operator '=' is not defined for Rows.Row
Any idea?
Thanks,
Miguel
Here's a question for you: Does your Search method ever return Nothing?
My Search method returns true or false. It is a Predicate to be used
under Generic.List Find. So basically I need to check if the Find
command found anything.
Anyway, If it helps here is my Predicate class:
' FindRowByName
Public Class FindRowByName
' -- [Properties] -------------------------------------------
' RowName
Private _RowName As String
Public Property RowName() As String
Get
Return _RowName
End Get
Set(ByVal value As String)
_RowName = value
End Set
End Property ' RowName
' -- [Methods] -------------------------------------------
' New
Public Sub New(ByVal rowName As String)
' Define class properties
Me.RowName = rowName
End Sub ' New
' Search
Public Function Search(ByVal row As BoxRows.Row) As Boolean
' Return comparison value
Return String.Equals(r ow.Name, Me.RowName)
End Function ' Search
End Class ' FindRowByName
Thanks,
Miguel
On Mar 13, 3:01 pm, David Anton <DavidAn...@dis cussions.micros oft.com>
wrote:
Even though VB allows the use of "Nothing" with structure types (such as
Int32 for example), it tends to be confusing (and requires overloading the
Equals operator). What you should do instead is have a read only property on
your structure, such as "IsInitialized" , which returns true if the instance
is explicitly initialized or populated.
--
David Antonwww.tangib lesoftwaresolut ions.com
Instant C#: VB to C# converter
Instant VB: C# to VB converter
Instant C++: C#/VB to C++ converter
Instant Python: C#/VB to Python converter
"shapper" wrote:
Hello,
I have a generic list as follows:
Dim rows As New Generic.List(Of row)
Now I have a row:
Dim myRow As row
I tried to check, further in my code, if the row is nothing:
If myRow Is Nothing Then
....
End If
I get an error:
"Is" requires operand that have reference types but this operand has
the value of Rows.Row"
Any idea what I am doing wrong?
Anyway, this is my row definition and its dependencies:
' Row
Public Structure Row
' -- [Properties] ----
' Cells
Private _Cells As Generic.List(Of Cell)
Public Property Cells() As Generic.List(Of Cell)
Get
Return _Cells
End Get
Set(ByVal Cells As Generic.List(Of Cell))
_Cells = Cells
End Set
End Property ' Cells
' Name
Private _Name As String
Public Property Name() As String
Get
Return _Name
End Get
Set(ByVal Name As String)
_Name = Name
End Set
End Property ' Name
End Structure ' Row
' Cell
Public Structure Cell
' -- [Properties] ----
' Content
Private _Content As Object
Public Property Content() As Object
Get
Return _Content
End Get
Set(ByVal Content As Object)
_Content = Content
End Set
End Property ' Content
' Culture
Private _Culture As CultureInfo
Public Property Culture() As CultureInfo
Get
Return _Culture
End Get
Set(ByVal Culture As CultureInfo)
_Culture = Culture
End Set
End Property ' Culture
End Structure ' Cell
Thanks,
Miguel
David,
I am a little bit lost.
You mean that I should create a New Method on my structure which sets
a property IsInitialized to true, being IsInitialized default value
set to false?
And how can that help me?
Remember I am using List.Find to get a row.
Thanks,
Miguel
On Mar 13, 11:46 am, "shapper" <mdmo...@gmail. comwrote:
On Mar 13, 3:11 pm, "Mike Hofer" <kchighl...@gma il.comwrote:
On Mar 13, 10:45 am, "shapper" <mdmo...@gmail. comwrote:
On Mar 13, 2:22 pm, "Mark Rae" <m...@markNOSPA Mrae.comwrote:
"shapper" <mdmo...@gmail. comwrote in message
news:11******** **************@ n33g2000cwc.goo glegroups.com.. .
If myRow Is Nothing Then
If myRow = Nothing Then
I have tried that before and it didn't work.
Basically my code is:
Dim myRow As Rows.Row = allRows.Rows.Fi nd(AddressOf
FindRowByName.S earch)
If rBox = Nothing Then ...
I get the error:
Operator '=' is not defined for Rows.Row
Any idea?
Thanks,
Miguel
Here's a question for you: Does your Search method ever return Nothing?
My Search method returns true or false. It is a Predicate to be used
under Generic.List Find. So basically I need to check if the Find
command found anything.
Anyway, If it helps here is my Predicate class:
' FindRowByName
Public Class FindRowByName
' -- [Properties] -------------------------------------------
' RowName
Private _RowName As String
Public Property RowName() As String
Get
Return _RowName
End Get
Set(ByVal value As String)
_RowName = value
End Set
End Property ' RowName
' -- [Methods] -------------------------------------------
' New
Public Sub New(ByVal rowName As String)
' Define class properties
Me.RowName = rowName
End Sub ' New
' Search
Public Function Search(ByVal row As BoxRows.Row) As Boolean
' Return comparison value
Return String.Equals(r ow.Name, Me.RowName)
End Function ' Search
End Class ' FindRowByName
Thanks,
Miguel- Hide quoted text -
- Show quoted text -
Okay, I gotcha now. So your FindRowByName method, what is its return
type? And what can it return? Does it ever return Nothing? This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics | |
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