Why Does Lambda Not Work With AndAlso
Jul 10, 2009I finally found out that my lambda in the following statement evaluates to false as opposed to the corrected version. Just wondering why:
CODE:
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Why Does Linq Lambda Work One Way But Not The Other
Dec 7, 2011I am learning MVC3 and transitioning to VB.NET from C# at the same time (Fun, I know). I am running through the MvcMusicStore sample for learning MVC3. All the samples are in C# so I am converting them to VB. I came across one piece of code that I was unable to directly convert and had to change slightly to get it to work.
why one way works and the other doesn't.
This does not work:
Dim albums = New List(Of Album)() From { _
New Album() With { _
.Title = "A Copland Celebration, Vol. I", _
[Code].....
Lambda Coding - Basic Code Of Lambda With Explanation
Jun 21, 2011Im hearing about this, can someone explain it to me or please show some basic code of Lambda with explanation.
View 2 RepliesLambda Tutorial And Solving A Lambda-Function
Dec 14, 2009Is it possible to shorten the following function to a lambda expression?Or (to do the trick by myself) what is the best and most understandable for beginners tutorial for lambda in vb.net?[code]
View 2 RepliesWhich Is Better For Performance, And Vs AndAlso
Jul 15, 2011When writing an If statement, I've always used And when needed like: If 1=1 And 2=2 Then. The only time I ever used AndAlso is if the second condition will error if the first isnt true like: If Not IsDbNull(Value) AndAlso Value=2 Then. However, recently I've heard that AndAlso is better for performance than And as the second condition is only read when the first is true. In this case, should I always just use AndAlso?
View 3 RepliesDifference B/w AND And ANDALSO Operator?
Oct 29, 2009What is the difference b/w the AND and ANDALSO operator?
View 3 RepliesDifference Between (OrElse And Or) And (AndAlso And And)?
Dec 7, 2011What is the difference between (OrElse and Or) and (AndAlso and And)?Is there any difference in their performances, let say the correctness benefit?? Is there any situation that I shoudn't use OrElse and AndAlso?
View 4 RepliesUnable To Run AndAlso Statement?
May 9, 2011Im trying to check service on a remote server.. as i was typing this i kept getting a syntax error on AndAlso statement.
Also, how do i add the path to connect to a remote server to check the service?
Private Sub CheckServiceButton_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CheckServiceButton.Click
' This will check if the service is running '
[Code]....
Understanding AndAlso - Get A Runtime Error?
Oct 5, 2011Looking at the following code snippet in VS2008 (this is from the SBS book)
Dim HumanAge As Integer = 0
If HumanAge <> 0 And 7 / HumanAge <= 1 Then
MsgBox("1 dog year or older")[code]....
I expect to get a runtime error, because And evaluates both conditions, which is why in this case AndAlso should be the better operator to use. When I try this code there is no difference in behavior between 'And' & 'AndAlso'. In neither case I get a
runtime error, not even when I flip the conditions around. Is this by design, a lucky accident, or do I just not get it?
.net - AndAlso In VB Linq Query Doesn't Seem To Be Working?
Sep 14, 2010The below query fails with Null Reference Exception when there are elements in BOMIDs where MatID property is nothing.I thought the 'x.MatID isnot Nothing AndAlso' would prevent the x.MatID.Process part of the where from being executed. There are a couple elements in the BOMIDs collection that where MatID is nothing.
From x In BOMIDs _
Group Join y As PurchasedProcess In SpecialProcesses _
On x.MatID.PurchasedProcess Equals y.Name _
Into G = Group _
[code]....
C# - Lambda Expression: CS To .Net?
Aug 24, 2011I am dumb founded at this statement....maybe its just too many hours/days of doing C# to VB.Net conversion but i am drawing a blank on this conversion.
List<string> sColors = new List<string>(this.CustomPaletteValues.Split(','));
try {
List<Color> colors = sColors.ConvertAll<Color>(s => (Color)(new ColorConverter().ConvertFromString(s)));
What i have so far:
Dim colors As List(Of Color) = sColors.ConvertAll(Of Color)(....)
As you can see its the content of the lambda that i am hitting a brick wall with.
C# - Use Or Not Lambda Expressions?
Nov 11, 2009I see lambda expressions have become a very useful tool at some points in the language. I've been using them a lot and most of the time they fit really nice and make the code shorter and perhaps clearer.
Now.. I've seen some , I would say excessive use of them. Some people like them so much that try to use them everywhere they can.. Some times the C# code looks like a functional language. Other factors against are the cost using reflection by lambda and that not friendly to debugging.I would like to hear opinions about how good and how code clear it is to use more or less the lambda expressions. (this is not the better example, but let's say it was the trigger)I was writing the following code. The use of the delegate { return null; } helps me avoid having to ask if the event is null or not every time I have to use it.
public delegate ContactCellInfo.Guest AddGuest();
public event AddGuest GuestRequest = delegate { return null;}
Im using resharper and the wise resharper( even it some times literaly eats the memory) made me the following suggestion
public delegate ContactCellInfo.Guest AddGuest();
public event AddGuest GuestRequest = () => null;
At my point of view the code using the delegate looks clearer. I am not against the Lamdba expression just would like to hear some advices on how and when to use them.
C# Lambda Conversion To VB?
Dec 21, 2009I have been looking at certain tutorials on sharparchitecture and trying to no avail (the online convertors don't seem to be able to do this):
private Action<AutoMappingExpressions> GetSetup()
{
return c =>
[Code].....
Convert C# Lambda To .net?
Jan 2, 2011converting this to VB.NET
public void GetCustomers(Action<IEnumerable<Customer>> onSuccess, Action<Exception> onFail)
{
Manager.Customers.ExecuteAsync(op =>
{
[code]....
Convert Lambda From C# To .NET?
Apr 20, 2010How would I translate this C# lambda expression into VB.NET ?query.ExecuteAsync(op => op.Results.ForEach(Employees.Add));
using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
[Code]...
Lambda - Using PredicateBuilder With .NET?
Oct 1, 2009I have recreated the Predicatebuilder class in a seperate C# project and I'm trying to use it in a VB.NET project but I keep getting the following error: Overload resolution failed because no accessible 'Or' accepts this number of arguments.when I use it like so:
Dim predicate = PredicateBuilder.False(Of t_Quote)()
predicate = predicate.Or(Function(q) q.iQuoteType = iQuoteType)
The relivant project is referenced, I'm using the correct imports statement and it all compiles without any errors.
[Code]...
Lambda Expressions In C# Vs. .net?
Jan 20, 2010Functionally, is there any difference (apart from syntax onbviously) between lambda expressions in C# and VB.Net?EDIT: following up on CraigTP's answer: any references to the situation in .Net 4?EDIT: I'm asking because I'm used to C#, but for a next project the customer asks VB.Net. We're not a priori against that. We realize that most language constructs are supported in both languages. However, we're particularly fond of the way C# implements lambda expressions. We would like to have an overview of the differences with VB.Net
EDIT: accepted CraigTP's answer for pointing out what I currently consider the most important difference.
So to summarize: VB.Net 9 does not support multiline statements in a lambda expression, and a lambda must always return a value. Both of these issues are addressed in VB.Net 10
.net - Convert C# Lambda Expression To VB?
Mar 23, 2012In looking at Fuzzy Date Time Picker Control in C# .NET? Piotr Czaapla's answer to that question is exactly what I need. unfortunately, I'm a VB.NET guy and I'm not that familiar with lambda expresions, so my attempts to convert the code have resulted in hours of misplaced parenthesis and banging my head with a brick.
Any chance some bi-lingual wizard could convert the C# code to VB.net for me?
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.Net Lambda Expression With No Intellisense?
Mar 9, 2011Using lambda's in VB.Net results in no intellisense. Is this a bug with VS2010 or expected? Note that it works fine in C#
Return Array.TrueForAll(chequeColl, Function(x) x.Number <> "N") 'No intellisense Number does not appear
Return Array.TrueForAll(chequeColl, Function(x As MyClass) x.Number <> "N") 'Now casted intellisense appears
UPDATE: Here's an example
Public Class Cheque
Public Property Id As String
Public Property Status As Byte
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C# - .NET Async Lambda-expressions?
Apr 20, 2012Async Sub like this: Dim f As Func(Of Task) = Async Sub() End Sub Produces compiler error: error BC36670: Nested sub does not have a signature that is compatible with delegate 'System.Func(Of System.Threading.Tasks.Task)'.Equivalent C# code compiles fine:
Func<Task> f = async () => { };Rewriting Async Sub into Async Function make code works.
Why does Async Sub() is not convertible to delegate types with return value of type Task?
Convert C# Lambda += Expression To VB?
Feb 15, 2011How should the following C# code be converted to VB.Net? I have tried several code converters and none produce correct results.
[code]...
Convert C# Lambda Function To .net?
Oct 6, 2011I have this function that maps a IDataReader to a class. It is obviously written in C#. My co-worker wants to use the same method in his code, but he is writing in VB.net. Basically I am having difficulty rewriting this due to the Lambda expressions used in C#. He is running .Net 3.5.
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Converting A C# Lambda Expression?
Dec 15, 2011I will probably sound like a bad developer here, but I am attempting to convert some code from the following page from C# to VB.NET:The code I am having trouble converting is from Step 4 of "Joining a Multicast Group" on the page, and here is the code with the comment lines removed:
private void Join()
{
_receiveBuffer = new byte[MAX_MESSAGE_SIZE];
[code].....
Converting Lambda Expressions To .net?
Jul 4, 2010how to convert this code to VB.net, can anybody help?
public static readonly DependencyProperty CommandProperty =
DependencyProperty.RegisterAttached(
"Command",
[code]...
Extract The Lambda From An Expression?
Aug 9, 2010I want to implement this function:
Public Function GetFunc(Of TSource, TResult) _
selector As Expression(Of Func(Of TSource, TResult)) _
As Func(Of TSource, TResult)
[code]....
UPDATE:I have the following issue, it's a part of a function:
Dim obj As Object = value
For Each exp In expressions
If obj Is Nothing Then Return [default]
[code]....
Exception Details:
ArgumentException:Object of type 'System.Linq.Expressions.Expression`1 [System.Func`3[System.Char,System.Char,System.Char]]'cannot be converted to type 'System.Func`3[System.Char,System.Char,System.Char]'.
Lambda - Anonymous Delegates In .net (pre Vb9)?
Apr 7, 2009Is it possible to create anonymous delegates in vb.net version 8 or earlier? If so, could someone provide an example of the syntax?
View 2 RepliesLambda Expression Not Working?
Jun 12, 2012If been try to convert some code I have from VB.net to C# but I just cannot get it working!first is the vb code I'm only interested in the line that has the Lambda Expression for the C#[code]......
View 2 RepliesLambda Expression Shorthand
Mar 30, 2010Currently, I have code similar to this:
xxx, _
If(dr.Table.Columns.Contains("EnterpriseID"), dr.Field(Of Integer)("EnterpriseID"), -1), _
xxx
I would like to create a Lamdba expression something like the following (this doesn't work):
Dim xCol As Func(Of DataRow, String, Type, Object, Object) = _
Function(dr, x, t, dflt) _
If(dr.Table.Columns.Contains(x), dr.field(Of t)(x), dflt)
So that I can say something like:
xxx, _
xCol(dr, "EnterpriseID", GetType(System.Integer), -1), _
xxx
Lambda Not Working On Array
Jun 17, 2011I have the following array
Dim items() = {
New CheckedListBoxItem("NYC", False),
New CheckedListBoxItem("CHI", False),
New CheckedListBoxItem("PHL", False),
New CheckedListBoxItem("SFO", False),
}
I am trying to query against it like this
Try
Dim item As CheckedListBoxItem = items.ToList().Where(Function(x) x.Value = "PHL")
MsgBox(item.Value)
Catch ex As Exception
MsgBox(ex.Message)
End Try
I am getting the error
Value cannot be null.
Parameter name: source
I also tried
Dim item As CheckedListBoxItem = items.FirstOrDefault(Function(x) x.Value.ToString() = "PHL")
I just need to query against the list to get an item and change it's checkedstate from false to true.
Sum The Counts With Lambda Expressions
Feb 3, 2012I have a List(of T) where T has a property that is a list of checkboxes, what I need is a Lambda expression that will count all the checked checkboxes in the list. I tried with:
[Code]...