How do I convert this code snippet from C# to VB.net

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I'm able to convert the PK line but not the following in my VS 2010 project. I've looked at expression trees, lambdas, etc. but haven't gotten anything to work yet. The automated tools I've found online don't convert it correctly. Any help would be appreciated.

C#

public virtual void ReadRecordFromDB<T>(Int32 ID) where T : class
{

...

C#

// find the primary key field name by checking for IsPrimaryKey
string pk = (dataMembers.Single<MetaDataMember>(m => m.IsPrimaryKey)).Name;

// return a single object where the id argument matches the primary key field value
var tbl = table.SingleOrDefault<T>(delegate(T t)
{
    String memberId = t.GetType().GetProperty(pk).GetValue(t, null).ToString();
    return memberId.ToString() == ID.ToString();
});

Posted 10-Jun-14 6:11am

David Belknap

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Richard Deeming · Answer 1 · 2014-06-10T09:03:00

Something like this should work:

VB.NET

Public Overridable Sub ReadRecordFromDb(Of T As Class)(ByVal ID As Integer)
    ...
    
    ' find the primary key field name by checking for IsPrimaryKey
    Dim pk As String = dataMembers.Single(Function (m) m.IsPrimaryKey).Name
    
    ' return a single object where the id argument matches the primary key field value
    Dim tbl As T = table.SingleOrDefault(Function (t2)
        Dim memberId As String = t2.GetType().GetProperty(pk).GetValue(t, Nothing).ToString()
        Return memberId == ID.ToString()
    End Function)
    
    ...
End Sub

David Belknap · Answer 2 · 2014-06-10T15:59:00

Solution 2

This solution looked promising but after I changed the == to a single =, then I got the error
"'t' is already declared as a type parameter of this method."
The t inside the Function(t) is highlighted as the error.

if I change the t to another letter then I get the error
"Statement lambdas cannot be converted to expression trees"

I'm still missing something simple with the syntax, I think.

Posted 10-Jun-14 15:59pm

David Belknap

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Richard Deeming 11-Jun-14 7:42am

Please don't post comments as new solutions; use the "Have a Question or Comment?" button under the solution.

VB is case-insensitive, so the lambda function's parameter cannot have the same name as the main function's generic type parameter. I've updated my solution.

David Belknap · Answer 3 · 2014-06-10T17:44:00

Solution 3

I gave up and kept it in C# in a separate project and called it from a VB project

Posted 10-Jun-14 17:44pm

David Belknap

How do I convert this code snippet from C# to VB.net

3 solutions

Solution 1

Solution 2

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