Why Do Optional Class Attributes In .NET Have A Different Syntax
Mar 11, 2009
I'm just curious why class/property attributes in VB.NET have a weird optional syntax such as:
<TestAttr("a", "abc", Optional1:="foo", Optional2:=3)>
VB.NET allows you to set optional parameters like this to avoid order restrictions (which is lovely) but in this case it's forcing you to that.For example this is not possible:
<TestAttr("a", "abc", "foo", 3)>
even though the parameters are in the same order as the original definition.
View 2 Replies
ADVERTISEMENT
Feb 25, 2010
I have an field, Address2, which is optional. Thus if it is null, no validation rules apply. However, if a value exists, its length cannot be greater that 255 characters.
I have been toying with:
<StringLengthValidator(0, RangeBoundaryType.Inclusive, 255, RangeBoundaryType.Inclusive, MessageTemplate:="Address 2 can be between 0 and 255 characters in length.", Ruleset:="MyRules")> _
But if it's not present, I still get an error.
View 2 Replies
May 13, 2009
I'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.
View 4 Replies
Jan 12, 2010
Most of our code base is in VB.NET. I'm developing a project in C# that uses a lot of the assemblies from the VB.NET code.There are three relevant classes in VB.NET:
[Code]...
View 3 Replies
May 30, 2012
Is this possible to use <Attributes> on a method in a Class extension ?Here is a Class A
Public Class Goblin
Inherits Monster
Enum goblinsRole
[code].....
View 1 Replies
Oct 7, 2011
Python has a setattr to set public attributes for any class on the fly.
So, how to do that with VB.net ?
[Code]...
View 2 Replies
Sep 1, 2009
How can we apply attributes to class fucntion using AOP in C#?I am slightly not clear in what context AOP should be used? As we can use AOP for logging purpose, security(Authentication), please suggest some other scenarios where we can take benefit of AOP.Is AOP can be use to share data among different running threads in application process?
View 2 Replies
May 29, 2012
I want to invoke a method on a class that i have a reference to. The method that I want to call has a custom attributes. Currently I can find this attributes and call the property of my class Attribute.
is there a way to invoke that method ?
PS/ The project is written in vbnet, but I think the solution is the same in c#.
View 1 Replies
Oct 27, 2011
Given the following class
[Code]...
How can I read the custom attibutes of the CustomerID or any other property?
View 1 Replies
Sep 27, 2011
I have an API that I created and currently utilize successfully in C#. I am trying to create an example of interacting with the API in VB.NET (so that the QA without C# experience can still utilize it for creating automated tests).
In C# I do the following
[TestingForm(FormName= "Land Lines", CaseType= _caseType
, Application= ApplicationNameCodes.WinRDECode, HasActions= true)]
public class LandLines : RDEMainForm
[Code]....
This gives me a compile time error because it claims that FORM_NAME and CASE_TYPE is not defined, even though the class has it defined inside.
How can I use the defined constants inside the class in the class attributes?
View 1 Replies
Jan 4, 2011
I am trying to retrieve the Attributes of a class's property specifically. So for example. Let's say I have a class called "Employee", and a custom attribute called CustomLabelAttribute with a string value. What would I need to do to retrieve the value of CustomLabelAttribute for Employee.FirstName specifically? I assume I will need to use reflection, but it's kind of new to me, and I've just recently started using it on any level.
[Code]....
View 3 Replies
Nov 1, 2011
Simple thing, well, I think it is.I need to Add a class to an element within an asp:repeater under certain conditions, using VB.
So, I can do
ITEMID.Attributes.Add("class", "classToAdd")
But this removes the existing classes and therefore screws up my CSS.
[code].....
View 2 Replies
Apr 7, 2011
I've added a new class1.vb file to my vb.net project containing:
Namespace MyFunc1
Public Class MyFunc2
Public Function Add(ByVal n1 As Int16, ByVal n2 As Int16) As Int16
return n1 + n2 ' Edited from: "Add = n1 + n2" (same thing)
[code]....
In form1.vb I thought I used to be able to call my functions with:
n = MyFunc1.Add(15, 16)
The error says "it's not a member".These also don't work as expected:
n = MyFunc2.Add(15, 16)
n = MyFunc1.MyFunc2.Add(15, 16)
n = Add(15, 16)
I thought for sure, this used to work:
n = MyFunc1.Add(15, 16)
View 2 Replies
Nov 10, 2010
I have two user controls that need to add a class atribute to the body tag of my page, however they currently over write one another if I just use Body.Attributes.Add("class","value") So I need to check if the class attribute exsists and if it already contains the value Im going to add.
If Not Body.Attributes("class").Contains("value") Then Body.Attributes.add("class", Body.Attributes("class") + " " + "value") End If
EDIT: The contain constraint doesnt return the expected value, resulting the the class not been concatinated, Example: add class "dog" then I a different instance of the same control tries to add "dog" but the contains("dog") returns false
View 1 Replies
Dec 10, 2010
I have the following XML file
<Test>
<Modules>
<Module Name= "Test1">
<QueueName Name="Test1Active1" Active="True"></QueueName>
<QueueName Name="Test1Active2" Active="True"></QueueName>
[Code]...
View 1 Replies
Mar 6, 2010
I am trying to have an optional Date value in one of my sub but since you cant set Date to nothing, this doesn't work. And i cant set it to the Date.minvalue inline.
Private Sub abc (ByVal A As String, Optional ByVal B As Date = Nothing)
End Sub
So, i went and set it to some date in the past.
Private Sub abc (ByVal A As String, Optional ByVal B As Date = #1/1/2001#)
End Sub
what would be the proper way to handle the default value for an optional Date?
View 3 Replies
Oct 12, 2011
I am having an issue trying to figure this out. I am writing a script editor that uses tabs (a tab control) and I want to implement syntax highlighting. My issue is that every sample I can find on syntax highlighting uses
Private Sub RichTextBox_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles RichTextBox1.TextChanged
View 1 Replies
Dec 16, 2009
Can any one translate the following syntax to vb.net.
m_TextBox.Loaded += TextBoxLoaded
m_TextBox.Loaded -= TextBoxLoaded;
private void TextBoxLoaded(object sender, RoutedEventArgs e)[code].....
View 4 Replies
Jun 26, 2012
I'm trying to convert come vb.net code into C# from another programmers old work but came across optional in one of the functions.[code]...
It seems like instead of using overloading, VB.Net has an option to create it into one method/function. Does C# have a similar equilvalent or do I have to create a method for each possbility?
View 3 Replies
Dec 21, 2009
I have a third party dll that contain a class, SampleClass1
Public Class SampleClass1
Public SomeValue As Double
Public Function Test() As Double
[code]....
My intention is if the dll is found, use it. Else ignore it. However, if the dll is not found, the program throw an Invalid OperationException.
View 7 Replies
Jan 27, 2010
I have an application that does a search of our database (exposed via EF) for records meeting certain conditions. We have two main tables (Jobs and Recipients). Recipients are linked to the Jobs table by a Job ID.The job record has various fields (Process Date, NameJobType). The recipient has a lot of Name and ID fields (e.g. Account Number, Surname, etc)
View 1 Replies
Oct 15, 2009
I currently have this XML schema :
<PSC5>
<POI_ORI>
<CIT>LIM</CIT>
</POI_ORI>
</PSC5>
if user want to add a new option, the final schema will be :
[Code]...
View 3 Replies
Mar 30, 2012
I'm looking at an old module to add some new features. I noticed this in a subroutine declaration:sub foo(...,optional fum as integer = 0)the later if not isnothing(fum) then <do something>I'm wondering, will <do something> ever be executed? I'm guessing not, since fum has a default value, but I want to be sure I'm getting this correctly.
View 12 Replies
Mar 16, 2011
It says that I can't have structures as optional arguments.That's really annoying for my program. Isn't there any way to circumvent this?
Sub fa(Optional ByVal colz As System.Drawing.Color = Color.AliceBlue)
End Sub
This example cannot compile
View 14 Replies
Apr 25, 2012
I have an application that does a search of our database (exposed via EF) for records meeting certain conditions. We have two main tables (Jobs and Recipients). Recipients are linked to the Jobs table by a Job ID.The job record has various fields (Process Date, Name, JobType). The recipient has a lot of Name and ID fields (e.g. Account Number, Surname, etc)I want to present a search screen where they see a list of fields to search on. The ASP.net code then sees which textboxes the user typed in (or selected), and builds a query based on that. [code] Where I'm stuck is figuring out how to add in additional where clauses. Should I just use Entity SQL?Can this return strongly typed EF objects as well? And is it possible to return both the Jobs and Recipients objects?
View 1 Replies
Mar 3, 2010
I have a method written in VB.NET. It looks like this:
Shared Sub SomeMethod(ByVal Id As Guid,
Optional ByVal str1 As String = "foo",
Optional ByVal str2 As String = "")
I want to call this method from C# 3.0 and I want it to use its default arguments. I tried passing System.Reflection.Missing.Value, but I cannot cast it as String. Is there any way to do that?
View 3 Replies
Aug 6, 2010
However, I am wondering if there are any workarounds or plans for incorporating this feature into VB.NET in the future?What I'd like to do:
Public Delegate Function Deserializer(Of T)(ByRef Buffer() As Byte, optional ByRef BufferPosition As Integer = 0) As T
'Implementation of a func that matches the delegate'
Class A
Public Function Deserialize(Byref Buffer() as Byte, optional Byref BufferPosition as integer = 0)
....
In the absence of specifying "optional" inside the actual delegate itself, it'd at least be nice to be able to do it in the function implementation only:
Public Delegate Function Deserializer(Of T)(ByRef Buffer() As Byte, ByRef BufferPosition As Integer) As T
'Implementation of a func that matches the delegate'
Class A
Public Function Deserialize(Byref Buffer() as Byte, optional Byref BufferPosition as integer = 0)
....
At least this second way, the functions for the delegate will always have a value mapped to each parameter, although some may come from the function side and not the calling side.
View 2 Replies
Mar 14, 2012
How can i create a optional parameter in C# as we create in VB.Net
Public Sub Demo(ByVal a As Integer,Optional ByVal b as integer=3)
End Sub
I want to declare this in C#
[code].....
View 2 Replies
Feb 23, 2012
I am retrieving several properties of a control. Here is how I used to retrieve properties (with pinfo of type PropertyInfo):
value = pinfo.GetValue(obj, nothing)
That worked well, but now I am facing a property that has a optional value, and I get an error message telling me that the number of parameters is incorrect. So I changed my code by this one:
Dim index As Object() = {Nothing}
value = pinfo.GetValue(obj, index)
At this point, I didn't get any error message, but this code doesn't retrieve the good value. It only works if I replace Nothing by the default value provided by the property accessor...
But I don't know in advance what this default value is! And this code is within a function that retrieves properties that doesn't have optional values, so I cannot change the code especially for one case or another..
I am working on .NET 2.0
EDIT: More precisions about the case leading to the problem
Here is an example of property leading to the problem:
ReadOnly Property Foo(Optional ByVal Number As Integer = -1) As String
Get
If Number = -1 Then
[Code]....
With this kind of property, none of the codes above retrieve the good string.
My best guess would be to try the first code for general purposes, catch the appropriate exception, and then dynamically retrieve the default value of the parameter (Number in that case) and its type, so that I can call getValue with this default value.
So, How can I retrieve the default value of the optional parameter?
View 2 Replies
Dec 21, 2010
I tried DbNull.Value but no luck. How do I assign a default value as null to a string parameter that is null in VB.NET? Its litte strange to see that VB does not have anything like plain null as most of the other languages do. Also what is the difference between null and DbNull and Nothing.
View 3 Replies
