.net - Inline Delegate Predicate Not Working
Jan 27, 2012This is my problem. If I write this -
[Code]...
But I'm just out of my wit why this code, written to do the same thing is not working -
[Code]...
This is my problem. If I write this -
[Code]...
But I'm just out of my wit why this code, written to do the same thing is not working -
[Code]...
I am having a generic ListOf-collection holding the self-created User-object, I can filter for users by using lambda-expression like this:
Dim reviewers As List(Of User) = users.Where(Function(u) u.DvRoleID = 2).ToList
Instead of using the lambda expression I can also write the function and call it as argument like this:
Public Function GetReviewer1(ByVal u As User) As Boolean
If u.DvRoleID = 2 Then
Return True
[Code] .....
Now the question: why can't I create a delegate having the same signature as the GetReviewer1 function and use the delegate as argument inside the where-clause like this:
Delegate Function Criteria(ByVal u As User) As Boolean
Public Function GetReviewer1(ByVal u As User) As Boolean
If u.DvRoleID = 2 Then
[Code] .....
The compiler does not accept the crit delegate as argument.
I have used delegates multiple times over the years but for some reason this very simple code isn't working:Form has one button and on textbox. Simply trying to update the textbox from another thread and although it looks fine it's not working.[code] the parameter is being passed to the DoSomething, the UpdateTextboxText is being run and gets the correct string. But the textbox itself remains blank and I'm stumped.
View 1 Repliesfrom the documentation we have this: Multicast Delegate: Represents a multicast delegate; that is, a delegate that can have more than one element in its invocation list.
so am i right to say that Multicast delegate is no different from a normal delegate other than the fact that it has arguments. so System.Action is a 'normal' delegate whereas System.Action(T)(Byval obj as T) is a multicast delegate?
I've created a Delegate that I intend to call Async.
[Code]...
Code:
Public Class SendPings
Shared Sub New()
AddHandler Post.Saved, AddressOf Post_Saved[code].....
I get a error" Method 'Private Shared Sub Ping(item As BlogEngine.Core.IPublishable, itemUrl As System.Uri)' does not have a signature compatible with delegate 'Delegate Sub WaitCallback(state As Object)'.
So I have a some code I've been using for quite a while and it has worked fine. This project is rather large so I'm using a detailed namespace and I can't get it to work.[code]...
View 1 RepliesI have no chance to simple search a property in my property list by using the ".Title" of the property. Instead of using "For each > If .Title = SearchTitle" I prefer to do it with the Predicate and ".Find" methode.
Can someone help me to find out, how to avoid using the local variable " _SearchProperty" in the example below?
Private Sub NumericUpDownFrequency_ValueChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles NumericUpDownFrequency.ValueChanged
Dim PropFrequency As F_SCANT30_DEVICES.TB.Devices.clsFscanProperty
[code]....
My issue is to Find exact one Calendar object from a List Of(Calendar) by passing a particular date. I got to know about the predicate but not sure about passing parameter to it.
colorcode is List Of (Calendar) and calendar class has a property called DtmDate with which I want to compare and return the desired object. Dim a As Calendar = colourcode.Find(AddressOf New Calendar.FindByDate)
I got the predicate samples from Google and reached till now. But not sure how to pass my parameter i.e. date to it.
I've got the following to sort entities by their job position. The desired order ist defined in another array. In C# this code works:[code]However I will have to convert this to VB.net. I read the equivalent would be something like the following:[code]This does not compile, gives me "Expression expected" right after the Function(x). What am I doing wrong?
View 1 RepliesI need to count the items that meet a criteria in a list(of structure) in .net 2.0. eg
Dim listcars as new list(or car)
Structure car
Dim Name as string
Dim year as integer
End structure
Now i need to count all cars with name toyota etc, how do i do it.
[URL]
Having a bit of trouble using the List.Find with a custom predicate i have a function that does this
[code]...
by doing it this way means i have to have a shared "currentKey" object in the class, and i know there has to be a way to pass in the values i'm interested in of CurrentKey (namely, keyname, and oldkey) ideally i'd like to call it by something like keys.Find(AddressOf FindByOldKeyAndName(Name,OldVal))however when i do this i get compiler errors.How do i call this method and pass in the values?
I am pretty confused about lambdas. What I am trying to do here is write a function that will return an object from a certain table with a certain criteria. So lets say I can write:
function GetRecord(TableName as string,Criteria as string) as object
'do the linq-stuff
end function
Now I don't care if the parameters are strings or lambdas or whatever, but the end result must be that at runtime I don't know which table and which criteria will be used. As sometimes I need to get a customer record by email and sometimes a product by id etc. If possible I would prefer returning a list of matching objects and then I would just use .firstordefault when I want 1 (such as by id...).
After browsing the internet on how to read RDF Triples, the only things i came up with were user created libraries and so on. Some MSDN documentation on Microsoft's website confused me as well, as trying to import the Namespace shown was not possible. (Maybe it's possible just in C#? no idea).So how would someone read an RDF Triple using VB.NET? RDF is an XML format in which data is stored in triples: subject, predicate, object.
Example:
<rdf:RDF
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:dc="http://purl.org/dc/elements/1.1/">[code]....
I am trying to write a VB.NET alternative to a C# anonymous function.I wish to call Threading.SynchronizationContext.Current.Send which expects a delegate of type Threading.SendOrPostCallback to be passed to it. The background is here, but because I wish to both pass in a string to MessageBox.Show and also capture the DialogResult I need to define another delegate within. I am struggling with the VB.NET syntax, both from the traditional delegate style, and lambda functions.My go at the traditional syntax is below, but I have gut feeling it should be much simpler than this:
Private Sub CollectMesssageBoxResultFromUserAsDelegate(ByVal messageToShow As String, ByRef wasCanceled As Boolean)
wasCanceled = False
[code].....
i have an VB.NET application with few functions i need to debug (like ie. Assert in C#). Is it possible and how i do that ?
Public Shared Function createNumberArrayList(ByVal startValue As Integer, _
ByVal endValue As Integer, _
Optional ByVal isBackwards As Boolean = False) As ArrayList
[Code].....
Basically what i need is to enter few values and see if the function works and returns proper ArrayList.
strtest() = objFile.ReadToEnd.Trim.Replace(vbCr, "").Split(vbLf).Distinct.ToArray
I created this command from a few examples which reads the text from a StreamReader, Trims, splits on EoL, and returns a unique list. My next command is a sort. I couldnt figure out how to add a sort to this command. Its really not that important but I was curious if there�s an easy way.
Additionally if there's a better way to take a text file into an array or collection I'm all ears.
Tell vb.net equivalent of following method:
CODE:
Which on build in visual studio 2005 gives an error.
I need a inline calculator for a textbox.
When the user types 45*10+5 i need to have the answer displayed as 455 in the same textbox
Any one with a briljant idea of how to sovle this.
I know that this should probably be under mobile development .. but no one seems to use that thread ... so anyway .. here is what i am trying to do:
TreeView1.LabelEdit = True
With TreeView1.Nodes.Add("asd")
.BeginEdit()
End With
The above works for a windows application ... but i was wondering how i could do this on a windows mobile application as LabelEdit and BeginEdit don't exist!
I am trying to do an inline IF statement inside a asp:Repeater control to add a class to the first item, but I can't quite seem to figure it out. Basically the code I have right now that is not working but should give an idea of what I'm "trying" to do looks like this.
<asp:Repeater ID="rptrTabRepeater" runat="server">
<ItemTemplate>
<div class="tab <%= If Container.ItemIndex = 0 Then %>highlight<% End If%>">
'Other stuff here
[code]....
I have tried using the OnItemDataBound event but the delegate interface cannot return a value. If I'm going to do anything from a code-behind function really it would just need to be an "echo" kind of function which I wasn't quite sure how to get the item index in a code behind function.
EDIT: The compile error I am getting is:
Compiler Error Message: BC30201: Expression expected.
Is there any way to include some kind of auto-generated comments as part of implementing an interface? Studio automatically fills the headers for the methods, can I auto-fill some sort of code comments at that same time? (to help remember what each interface method is supposed to do without looking at external documentation.) For example, if I could get the interface's XML Intellisense markup headers to copy from the interface down to the implementation's level.
View 3 RepliesI have an element that I'm trying to style:
<tr runat="server" id="row" >
...
</tr>
And I set the style programmatically:
row.Attributes("style") = "background: #cccccc;"
I get this output:
<tr id="SearchResults_myRepeaterPlain_ctl04_row" style="background: rgb(204, 204, 204) none repeat scroll 0% 0%; -moz-background-clip: border; -moz-background-origin: padding; -moz-background-inline-policy: continuous;">
Where is all that additional style information coming from, and How can I stop it?
Just out of curosity, what's wrong with the following line. I'm trying to create a range of integers (3,4,5...,50) and then filtering out only those numbers which are not divisible by any integer less than themselves (bruteforce way of finding primes).
Enumerable.Range(3, 50).Where(Function(x) Not Enumerable.Range(2, x - 1).Any(Function(y) x Mod y = 0))
I would like to know if there's any way to specify an inline array (lets say of strings) to custom attribute on a property in vb.net.
I have the following example that doesn't compile in vb.net (.net 1.1):
Attributes.ManyToOne(New String() {"a", "b", "c"})> _
Public Property PaymentTerms() As PaymentTerms
[Code]....
I get compiler error when I feed the array to the custom attribute in vb.net. I have no problem in C#, just vb.net. What is the correct syntax in this silly language?
tell vb.net equivalent of following method:
C# Syntax
public class RecentPosts : Control
{
[code].....
I have to join two main tables, and I need to filter the results by elements in an ASP.NET web form. These filters are created on the fly so I have to use a lot of where extensions to filter the query. I want to execute the query with as optimized SQL as possible.
I am first doing a simple join between TW_Sites and TW_Investigators. Then there are two sub-tables that are involved. TW_InvestigatorToArea and TW_InvestigatorToDisease. While most of the where clauses are working fine, I have found a performance issue that won't be an issue right now, but will be an issue as the table gets bigger.
The arrays DiseaseCategories and DiseaseAreas would be the results of a CheckBoxList result.
Protected Sub LoadResults()
'Get Dictionary of Filters
Dim FilterDictionary As OrderedDictionary = Session.Item("InvestigatorFilterDictionary")
' Initialize LinqToSql
[code]....
Suppose we have a class like:
Public Class Question
Private Shared _field as Integer = CrazyIntegersRepository.GetOne()
' Some other useful things go here
End Class
And the method GetOne throws an exception... How can we manage that? Is a good practice to rewrite that into a static constructor? When is the GetOne method going to be executed if we leave it there in the inline _field declaration?
Check out this code sample from Scott Guthrie's blog: [URL]...Notice item is a reference to the currently executing item in C#, what is the equivalent keyword in VB.NET?
EDIT: I should add here is my actual implementation of a method accepting a template:
Public Function RenderInlineTemplate(ByVal template As Func(Of RazorSamplesWeb.Models.SamplesModel, Object)) As IHtmlString Return New HtmlString("<div style='display:inline;'>" + template(Model) + "</div>")
End Function And I get this error: Compiler Error Message: BC30201: Expression expected.
[Code]...
I'm working on a legacy vb.net application that does most of its work using inline code ( Within that script I need to access functions from a third party .net dll. The dll(s) themself are stored in the GAC. Before I started the page looked something like the following
[Code]...