Is there ever a situation where I should do the following in .NET instead of using a property with read/write capability?
private S as string
public function GetS() as string
[code]....
Do properties simply provide a more efficient way for doing the same thing?Will properties be any slower than the above accessor functions in a high performance application?
I'm using LinqToSql classes in an ASP.NET website and let's say I have an entity named Testimonials. Two pages utilize this type - the first being a list of all existing Testimonial records and the second being an add / editor with which to manage the records. [Code] This allows population a DataGrid with the returned items, however on the add / editor page we alter the query ever so slightly: [Code] This query dies, prior to even trying to populate anything, with the following message: [Code]
I have pretty much identical methods for other data objects which have been and still are executing just fine. One immediate difference I can think of is that this table has been recently updated in the database, removed from the dbml designer and re-added to the dbml designer. None of the other tables have undergone this process for some time. [Code] Why is this exception occurring and how can I configure my project appropriately to correct the issue?
I have been wondering for a while what the difference is between the following two:
Public Property ProgressMaxValue() As Integer
Get
Return maxval
End Get
[code]....
What are the pros and cons of using the checkboxes checked property vs the CheckState property for databinding?
View 1 RepliesThese two snippets do the same thing - is there one that's better than the other, or is it just a matter of preference?
Using context As MyDatabaseDataContext = New MyDatabaseDataContext()
Dim test = context.Employees.Count
End Using
vs.
Dim context As MyDatabaseDataContext = New MyDatabaseDataContext()
Dim test = context.Employees.Count
Now I have the need to get a current value from a bindingsource in a property of a user control.In a previous thread I had tracked down the "Object variable or With block variable not set" to the return in the Get block of a property. At the time I was only using the Set so I just commented out the offending code until I needed it.
[Code]...
The error does not occur during a system compile, only upon saving the container object of the user control. As I said the Set works correctly, only the Get causes the error.I would like to know what I am missing/misunderstanding and am open to other suggestions of handling retrieving the current value of a bindingsource in a user control.
I want to assign an object property by referencing the property dynamically, with a variable name
i.e.
dim propName as string
staticObjectName.propName = 'whatever
just want to know what is the difference between these date values?Once some one told me that its difference is server date and client date but not sure which one he meant.Below is 3 type of date currently I'm using and don't know what is the difference between them.
DateTime.Now is from System.DateTime.Now
Now is from Microsoft.VisualBasic.DateAndTime
Today.date is also from System.DateTime
Public Class Form1
Dim x, c, number(0 To 19) As Integer
Dim s As Integer
[CODE]...
The variables in the brackets [example] do not actually have brackets in them in the original code. These are where the issues are. For both variables, it says, "The type for variable [variable] will not be inferred because it is bound to a field in an enclosing scope. Either change the name of [variable], or use the fully qualified name (for example, 'Me.[variable]' or 'MyBase.[variable]')." Now, I'm not entirely sure if this is a stupid question or not, as I'm used to VB '98 because that's what we use in my programming class at High School. let me know why this won't work.
-Note: The intention of this program is to continually loop the generation of numbers for this list until I tell it to stop. Button1 ends the program, Button2 generates the list one time only, Button3 is supposed to loop the generation of the list, and Button4 is supposed to end the loop, but not the program.
I have the following code that I am using to parse out a test file. I am getting variable conversion error in Sub Main() when I assign file = Read(). The return value of Read() is a TextFieldParser type. How do I assign the proper variable type to "file" so I can write the output to a text file?
Function Read()
Using MyReader As New FileIO.TextFieldParser("C:UsersColinDesktopParse_Me.txt")
Dim currentRow As String
[Code].....
I'm currently working with a client's VB.Net code, which was developed for them by a small development shop a few years ago and which they purchased and have been maintaining and uprgrading since. This client's primary developer is out on indefinite (likely permanent) medical leave and I'm now filling in until they bring in a full timer (as I'm a contractor here). My current task is to add some functionality to a the VB.Net code they purchased. I'm finding practices and techniques in the code that absolutely baffle me and can't make the code do what I want. I'm starting to wonder if it's me and was hoping to get some thoughts on the code I've encountered.
For example: Setting a variable to accept the result of a function by calling the function with many parameters, clearing the parameters in the function, setting them to some value, calling another function with those new values, then never using the values returned by the functions. I'll add a code snippet in the first comment since this is already getting long.
I am working on a application that has quite a few functions involved and have been thinking of the following: If I have a function that has a few paramaters, is it more efficient to pass the objects to the function(Example 1) or reference the objects in the parent(Example 2)? Does it matter if the objects are large or not?
Example:
Class mainform
Public myGenericList As New List(Of String)
Public myDatarowArray() As DataRow
[Code].....
I have created getter setters before. But how do I make a read only accessor in VB.net? I want a value to be read, but not to be set.
View 4 RepliesI'm trying to make alterations to an existing project, and I've found a project in the solution which is full of generated classes.Problem is, nobody here can tell me what generated them, so I'm pretty much left with pasting one of the classes in here and hoping someone will be able to tell me where they came from.
The solution I'm working on uses Expression Blend 3 and Visual Studio 2008. Dunno if that's relevant, but I'm trying to give as much information as I can think of... As well as this class, which appears in its own file, there's an "SPResults" file, which contains about 5000 lines of accessor classes of this type. Not quite sure why EndCustomer is in its own file...
From what I can see for myself, there's a stored procedure in one of the databases this program links to, and that SP's name is "GetEndCustomers". Something has then created a class called "EndCustomers" to represent the return type of this procedure.
The first part is a function from a class named Database, which returns a collection of the objects in question.
<FunctionAttribute(Name:="dbo.GetEndCustomers")> _
Public Function GetEndCustomers(<Parameter(Name:="Dummy", DbType:="VarChar(1)")> ByVal Dummy As String) As ISingleResult(Of Data.EndCustomer)
Dim result As IExecuteResult = Me.ExecuteMethodCall(Me, CType(MethodInfo.GetCurrentMethod, MethodInfo), Dummy)
[Code]...
So, yeah, can anyone tell me what has been used to generate this class? It could be something in Visual Studio, Expression Blend, SQL Server Management Studio, or some obscure bit of software I haven't even noticed is on the PC. Any clues, anyone?
I have created a structure with the following elements:
<StructLayout(LayoutKind.Sequential)> Public Structure person
Public userid As Integer
Public age As Integer
[code].....
I'm designing an application for a class where the user inputs three values and the program tells them whether it is a right triangle, equilateral triangle, or neither.I'm trying to figure out how to test for a right/equilateral triangle in my get accessor.... Here is the code so far for the class:[code]......
View 1 RepliesI've got a basic logon form where if you enter the right password/username, it redirects you to the "MainMenu" Form How can I make a function called "checkLogon" that checks the username/password text to a variable in that function?
View 3 RepliesI have a web service created with vb.net in vs 2010. Here is a look at my property
Public Class MyClass
Inherits ConfigurationSection
Protected _score As Integer
[code].....
When I try to add this as a service to a web app, also done in vs2010 with vb.net, I get the error in the title. Please help with this. I am not sure what is needed in order to implement a default accessor.
I have a Property of City/Town. My objectdatasource will not recognise this as a property variable ?
View 5 RepliesI have the following
Public Structure Foo
dim i as integer
End Structure
[code].....
I have a project in WPF 4 and VB.net 2010. I want to bind the volume property of a mediaelement to a variable in another module. Mind you, the variable is in the correct data type, so no conversion is necessary
View 1 Replies[code]...
In the above code i have created a reference to class B from class A. The reference variable "refB" created as a attribute. But i need to encapsulate this reference variable in a property also i need to ensure than instantiation reB = New B() is done even after the use of properties.
1. How do i encapsulate the class reference variable "refB" in property?2. If i hide this class variable "refB" in a property, how do i write the code code initilize "refB" in "A"'s constructor?
I am working in VB.Net 2010 framework 2.0. Suppose i declares a property
[Code]....
In the form designer, the property "MyColor" will be seen the value as 150, 145, 145. I want to see this value as "NewColor" in form designer. This is the same like ControlDark, ActiveBorder etc. system colors. I want that instead of the color value, designer should show the variable name. The .Net framework also use the above implementation for System Colors and same i want to do.
How can I make an event that is raised when a variable or property is changed (or can I just put the code I would put in an event in the Set section of a property?
View 5 Repliessay i have an auto property Public Property P As Integer and everytime I want to read this variable P in a function, i will declare a local variable as such: dim _p = P then read _p instead of P. I'm wondering does it make sense at all? will it actually make things slower (which of course isn't my intention).Btw if we change the question to Public Property P As Object is there any change in the answer?
View 7 RepliesI have in my My.Settings four settings [code] now I want to get the value of the current setting from the My.Settings.SettingName. [code]
View 1 RepliesSo Im iterating through the properties of a class. For each property Im iterating through a datatable until I find a column name with the same name as the property.
No worries so far, here's the isse: Once I've found a match I want to set the class's property to the value in the datatable but I'm having difficulty referencing the property as it has to be done through a variable.
Code:
Dim per As New Person
Dim t As Type = per.GetType
For Each p As PropertyInfo In t.GetProperties
[Code].....
In the application I'm documenting, sometimes a value is stored in a Public variable & other times it's passed to/from a Public Property which does nothing except store it in/retrieve it from a Private variable. (And in one memorable exception, the Public Property stored it in a Public variable-I'm almost certain that was an oversight by the original programmer though.)
I know that passing it to/from the Public Property has the potential for better validation, but if the Property doesn't actually do anything except store/retrieve it is there any benefit to declaring it as a Property? (Or maybe I should put that the other way around. Personally I'd declare them all as properties because that will allow adding validation later-but I'm not rewriting this, I'm just trying to document it and, in this case, trying to figure out why sometimes it's done as a property & sometimes as a Public variable.)
Public Class Command
Public Property CFunction as ?Function?
Public Sub CallFunction()
[Code]....
I was wondering if there was a way to get the name of the property my statement is in, like I can get the name of a function in PHP with the magic constant __FUNCTION__. Is there a way to get that property name, and more in general, also for functions and methods?
View 1 Replies