I have the following XML file
<Test>
<Modules>
<Module Name= "Test1">
<QueueName Name="Test1Active1" Active="True"></QueueName>
<QueueName Name="Test1Active2" Active="True"></QueueName>
[Code]...
I'm trying to create a list of all my objects from several lists of objects using Union.
Return Chart.AnnotativeNodes.Union( _
Chart.DecisionNodes.Union( _
Chart.EndNodes.Union( _
Chart.StartNodes.Union(Chart.WorkCenterNodes))))
The above line gets an error because I can't union List(of AnnotativeNode) with List(of DecisionNode). Each list defined like List(of EndNode) or List(of StartNode), but each class inherits from the base type Node.Is there a possible way to union these to get a result of IEnumerable(of Node)?
What is the VB.NET syntax for declaring the size of an array of objects at runtime?To get an idea of what I mean, here is the code so far:
Private PipeServerThread As Thread()
Public Sub StartPipeServer(NumberOfThreads As Integer)' ??? equivalent of C#
' ??? PipeServerThread = new Thread[numberOfThreads];
[code].....
Base class has one field to hold numeric balance value. With 2 methods that accept arguments for adding and subtracting the new input calculating new balance. Sub class has four fields dates, transaction, memo and amount.I have a deposit form, and withdraw form. Each time one transaction is entered it creates an object with sub class fields, then adds to the account collection. My problem is not understanding how to call the deposit/withdraw method and pass the current transaction amount back to the base class to alculate the new balance. Does anyone have any links to information/tutorials on how to perform something like this? As you can see with my code I have tried various different approaches without any success.
[Code]...
If I have a class that inherits another class in which there are objects that are disposed in the dispose() procedure, do I use mybase.dispose? ex Class A inherits Class B. [code]
View 2 Repliestell me the equivalent syntax for the following code in VB.net?
Static Class TestList
{
static void Main()
{
[code].....
I ran into this answer which had a triple dot syntax in VB.NET that I have never seen before. The query looks like this
[Code]...
After I have programmed several projects in VB.Net I to my surprise discovered that there are some more than subtle differences between C# and VB.NET LINQ usage.For example, if we want to group elements by multiple properties (columns) we need to create a new anonymous type explicitly:
var procs = from c in Process.GetProcesses()
group c by new {c.BasePriority, c.Id} into d
select d;
whereas in VB.NET more straightforward syntax will already do:
Dim b = From c In Process.GetProcesses()
Group c By c.BasePriority, c.Id Into Group
Select Group
So, one does not need to create a type with "new" here. What are the other differences? good comparison between the LINQ syntax in C# and VB.NET?
I'd like to do a subtraction of sets based on criteria. A pseudo-query would look like:
select table1.columnn1
,table1.column2
from table1, table2
[Code]....
I can make it to about here:
dim list = From tbl1 In table1 Where tt.column1 ...
What I really want is to select these two tables in to an anon type like in Scott Gu's blog: here However, I would settle for this created type "ActiveLots" I am joining two tables together and want to be able to reference columns from each in my result set. [code]...
View 1 RepliesI'm a bit of a LINQ newbie and I was having some trouble with the following. I'm trying to perform a query using LINQ on an XML file and store the results in a list of DataClass objects that match the XML.I've got an XML file that is defined like this:
<NewDataSet>
<NewDataTable>
<Field>Accepted ASNs</Field>
<Val>59</Val>[code]....
I have created a Data class to support this XML format. What I would like to do is create a LINQ Query to grab these 3 records and store them into a List of my DataClass. In order to support multiple Order elements, I have my class defined with a generic list of "Order" structs... It looks like this:
Public Class ASNData
Private _field As String
Private _value As String[code].....
how to grab the 3 order elements and store them into my list of Order structs.
I'm trying to grasp the linq to xml 'inline query syntax' features of VB.Net First I tried with this simple xml file:
<?xml version="1.0" encoding="utf-8" ?>
<Root>
<Child Name="somename">
[code]....
This xml, when loaded in an XDocument, can be loaded and queried as follows:
Dim xdoc = XDocument.Load("sample.xml")
Console.WriteLine(xml.Root.<Child>.@Name)
Then I change the <Root> element in the sample xml file to:
<Root xmlns="http://SomeNamespace">
Now I can't seem to use the convenient 'Axis Properties' syntax anymore... I can only get it to work with the explicit XElement syntax:
Dim ns As XNamespace = "http://SomeNamespace"
' works, but I would like to use the same syntax as above...
Console.WriteLine(xdoc.Descendants(ns + "Child").First().Attribute("Name").Value)
I am building an xml file with the help of Linq queries and I'm not sure why the code below doesn't work.[code]
View 1 RepliesI am trying to AVERAGE 6 different fields on a DataTable, but without grouping. Just the AVERAGE. I have found a couple of examples in C#, but can't find any examples for how to do this in VB.Here is what I have so far:
Dim query = From dtRow In dtIn.AsEnumerable _
Where dtRow.Field(Of String)("FOLLOWUP") = "Alert" _
Select New With { _
.Brand_Functional_Avg = XXX.Average(Function(f) f("Brand_Functional")), _
.Brand_Personal_Avg = XXX.Average(Function(f) f("Brand_Personal")) _
}
What should I use for XXX? I tried all of the options that I could think of and nothing is compiling.
Trust me, if I could write this in C#, I would, but the project requires VB.
[code]The reason that this is a problem is that this is a collection of EventBase objects, but I'm trying to populate it with child classes instead. For example, I might have a JumpEvent class that inherits EventBase, and this is being put into the EventBaseCollection. That means that value.GetType() returns the type of JumpEvent, which as you might guess does not equal the type of EventBase.The goal of course is to simply loop through all of the various events without having to know anything about the sub-classes. Is there a way to determine the type of the base class so that the OnValidate call will work? Or is this just the wrong way to go about it altogether?
View 2 RepliesCan we create objects of a C# class from a VB.NET class and vice versa?
View 2 RepliesIn which situations I should use LINQ to Objects?
Obviously I can do everything without LINQ. So in which operations LINQ to code shorter and/or more readable?
I have a query that I cannot seem to replicate in expression method chain syntax. I have two tables "User" and "UserPayment". User and UserPayment have a one to many relation i.e. One User can have many UserPayments.
View 1 RepliesI have a LINQ to sql statement that joins 2 tables. I would like to add a order by clause on one of the columns. However the order by clause does not seem to take effect at all. right syntax in VB.net to achieve order by in the following:
Dim query = From dtIt In dbsomecontext.mytable
Join dtIl In dbsomecontext.anothertable On dtIt.ItemID Equals dtIl.ItemID
Where dtIl.IsAvailable = True
Order By dtIt.manufacturer
[Code]...
I have a linq query like that:
Elementos = From b In Elementos Where b.Value.IdGrupo = 0 Select b
"Elementos" is a dictionary(of long, MyObject). MyObject has approximately 50 properties.
The problem I have is that I have a new requirement to accept string parameter with a "where" condition. Something like "property1>10 and property2 like 'anystring' or property3<=25". (That means any property could have a condition. I have string and numeric properties.)
I'd like to keep using linq, adding the condition as it comes. I'm aware that it could produce an exception if the condition is misspelled or something, but that's acceptable (by try catchs). I wouldn't want to parse the string to build parameters or anything.
I am creating a tool that interfaces with an API for a CD/DVD burner. I have created several custom classes that will hold the information for the disk sets (which consist of a data path and a label file among other information. The DiskSet class has a list of Include objects. My proposed XML output would be something similar to the following:
<DiskSets>
<DiskSet>
<Name>MySet 1</Name>
[code].....
I am attempting to traverse the Includes collection (I have tried List and Binding List as I am also using this in a pair of datagridview controls) and it keeps returning Expression of type 'Object is not queryable. Make sure you are not missing an assembly reference and/or namespace import for the LINQ provider." How can I use LINQ to pull a list of the Include objects under each DiskSet object for transformation into XML? I am hoping to keep this restricted to this one block of code if possible.
What is the proper syntax for this:
Dim qry As <??> = From f In dirInfo.GetFiles("*.QBW") Select File = f.FullName, Include = True
Dim dt As DataTable = qry.CopyToDataTable()
I tried as "IEnumerable(Of DataRow)" but that didn't work. At runtime it said:
Unable to cast object of type
'WhereSelectArrayIterator2[System.IO.FileInfo,VB$AnonymousType_02[System.String,System.Boolean]]'
to type
'System.Collections.Generic.IEnumerable`1[System.Data.DataRow]'.
I've been trying to write this snippet of code in VB, can anyone see what is wrong with it? I am recieving an error on line 5.
Dim a1 = From rows In db.tPDMLinkUsages _
Where (rows.ACCESSDATE >= DateTime.Today.AddDays(-90)) _
Select New With _
{ _
[CODE]...
I'm trying to translate some C# LINQ code into VB.NET and am stuck on how to declare an anonymous type in VB.NET.[code]How do you translate C#'s new { ... } syntax into VB.NET?
View 2 RepliesUsing the following code:
Private Sub MakeMeSomeXmlBeforeRyanGetsAngry()
Dim db As New MyDBDataContext
Dim customer = From c In db.Customers Select c
[code]....
I am attempting to serialize my linq collection of customers. But it keeps throwing
Type 'System.Data.Linq.DataQuery`1[MyDB.Customer]' cannot be serialized. Consider marking it with the DataContractAttribute attribute, and marking all of its members you want serialized with the DataMemberAttribute attribute. See the Microsoft .NET Framework documentation for other supported types. My issue is that I have already marked the dbml Serialization Mode to UniDirectional and when I check the dbml codebehind all of the DataContract()> and DataMember()> elements are there. I have tried adding various dataloadoptions and setting deferredloading to false, but no luck.
How to Join the objects in a LINQ select in this sample (C# variants accepted as well):
Class Room
Public Area As Integer
End Class
Class RoomPair
[code]....
Im trying to use LINQ to query Objets. I'm doing the following:
Dim myList As Generic.List(Of MyItem) = (From ThisItem In LinqToSqlObject.Items _
Join Folder In LinqToSqlObject.Folders _
On Folder.Id Equals Item.Id _
[Code]....
This however will not return any item that has a ParentItemId of null. I am trying to do a left join so as to return all "Item" regardless of whether it has a parent or not. I am aware that this is feasible in C# by adding an "into X" on the join, and selecting from X.DefaultIfEmpty(), this however does not appear to work in VB.Net.
I have list object and I need to check id in a comma separated string using LINQ in VB.NET, something like this:
dim strId as String = "1,2,3,5,"
dim myList = from objmylist where objmylist.id in (strId)
I'm trying to figure out how to add an enumeration to an object with Linq. For example:
Dim thingBlock = <Things>
<Thing Name="Ish">
<SmallThing>Jibber</SmallThing>
[code].....
This feels like a completely basic question, but, for the life of me, I can't seem to work out an elegant solution.
Basically, I am doing a LINQ query creating a new object from the query. In the new object, I want to generate a auto-incremented number to allow me to keep a selection order for later use (named Iter in my example).
Here is my current solution that does what I need:
Dim query2 = From x As DictionaryEntry In MasterCalendarInstance _
Order By x.Key _
Select New With {.CalendarId = x.Key, .Iter = 0}
[Code]....
Is there a way to do this within the context of the LINQ query (so that I don't have to loop the collection after the query)?