Sorting arrays

[Najm]

Hi,
How would it be possible to sort an array of objects (my_class) based on one
attribute of that class?
suppose the class' attributes are the following
my_class:
attr1 as integer
attr2 as str


Thanks

 

[Cor Ligthert]

Najm,

In my opinion is the most simple solution to use a datatable or use a
collection.

I take always the first, however there are people who have difficult classes
or want to do some more work and than there is to create a collection class
a complete sample.

http://msdn.microsoft.com/library/d.../html/vaconCreatingYourOwnCollectionClass.asp

In my opinion will all other approaches lead to a lot of overhead.

Cor

 

[Najm]

Thanks for ur help,
if i understood, u suggest i use a datatable to store the data instead of
the array of that object.
I have another question:
suppose i bind that datatable to a datagrid. is there a way to have indexes
of the table stay the same as the datagrid in the case of a datagrid sorting
?
thanks

 

[Herfried K. Wagner [MVP]]

How would it be possible to sort an array of objects (my_class) based on
one
attribute of that class?
suppose the class' attributes are the following
my_class:
attr1 as integer
attr2 as str

CompareOperator
<URL:http://dotnet.mvps.org/dotnet/samples/codingtechnique/CompareOperator.zip>

 

[Cor Ligthert]

Najm,

That is standard, assuming it is a windowform datagrid. Than holds the
"sort" item the current sort method of the datatable.defaultview or a
dataview which is the datasource of your datagrid.

The currencymanager.postition is the item that you can use to get the
currentrow of a dataview.

dv(BindingContext(dv, currencymanager).Position)(0) holds the first field in
the current row

I hope this helps?

Cor

 

[chanmmn]

Try this:

Sub AddSort()

Dim w1 As New wantsort

Dim w2 As New wantsort

Dim w3 As New wantsort

Dim al As New ArrayList

Dim ic As New wantsortComparerName

w1.attr1 = 2

w2.attr1 = 3

w3.attr1 = 1

al.Add(w1)

al.Add(w2)

al.Add(w3)

al.Sort(ic)

End Sub

End Class

Public Class wantsortComparerName

Implements IComparer



Public Function Compare(ByVal x As Object, ByVal y As Object) As Integer
Implements System.Collections.IComparer.Compare

Dim xEntity As wantsort = x

Dim yEntity As wantsort = y

If xEntity.attr1 = yEntity.attr1 Then

Return 0

ElseIf xEntity.attr1 < yEntity.attr1 Then

Return -1

Else

Return 1

End If

End Function

End Class



Public Class wantsort

Public attr1 As Integer

Public attr2 As String

End Class

Good luck.
chanmm