Name An Event Handler Of A Private Variable In Following FxCop Rules?
Apr 22, 2010
On one side, in Vb.Net when you add an event handler to an object the created method is named: <NameOfTheObject>_<NameOfTheMethod>.As I like to have consistent syntax I always follow this rule when creating event handlers by hand.On the other side when I create private variables I prefix them with m_ as this is a common thing used by the community, in C# people use to put _ at the beginning of a variable but this is no CLS compliant.
Public Class Utilities Public Shared Function blah(userCode As String) As String 'doing some stuff End Function End Class
I'm running FxCop 10 on it and it says:"Because type 'Utilities' contains only 'static' Shared' in Visual Basic) members, add a default private constructor to prevent the compiler from adding a default public constructor."
I have a form in VB.NET that is used as a dialog in a mainform. Its instances are always locally defined, there's no field for it. When the user clicks the OK button in the dialog, it will fire an event with exactly one argument, an instance of one of my classes. Since it is always a local variable, how can I add an event handler for that event?
Code for the event, a field in MyDialog: public Event ObjectCreated(ByRef newMyObject as MyObject) Code for the main form to call dialog : (never mind the syntax) Dim dialog As New MyDialog() dialog.ShowDialog(Me) AddHandler ObjectCreated, (what do I put here?) //Or how do I add a handler?
Error1Option Strict On does not allow narrowing in implicit type conversions between method 'Private Sub searchResult_SearchFileMatches(sender As Object, e As Jam.Shell.FileMatchEventArgs)' and delegate 'Delegate Sub EventHandler(sender As Object, e As System.EventArgs)'. on RED Text
Im making a site in Visual Studio using vb and I have a variable in page_load but need its value in the event handler of a button for passing on session.
The event handlers in my parent class are never called though the events are raised in the child class.
The Code:
Public Class childForm Public Event checkboxchangedEvent(ByVal checkbox1 As Boolean, ByVal checkbox2 As Boolean) Private Sub checkboxchanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CheckBox1.CheckedChanged, CheckBox2.CheckedChanged
if for example i have two private sub I declared a local variable on private sub a... is there a way that private sub b could use the variable created on private sub a? Im asking because im in a problem in my app were using global variable is not an option to make the long story short
remove an event handler from within the event handler?
I have a class that gets data from a hand scanner. When the scan is complete and the data is validated, the class fires a custom "ScanComplete" event and returns the data in a custom EventArgs.
In the calling program, I'm creating an instance of the scanning class and adding a handler for the "ScanComplete" event. In the event handler I get the data that was scanned and then remove the handler.
It seems to be working but it feels wrong to remove the handler while I'm running inside the handler. Will this cause a problem?
I'm trying to complete this airline reservation application, but having a problem in this part of the question:Creat an event handler for the FlightBindingSource's PositionChanged event: select FlightBindingSource in the class Name combobox then select position changed in method name combobox to creat the FlightBindingSource's PositionChanged event handler. Write a code to access the currently displayed flight object and pass its flightNumber to method DisplayPassengers as a decimal.This Is my code so far:
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Public Class AirlineReservationForm Private database As New ReservationsDataClassesDataContext() Private Sub FillAll()[code].....
When I utilize AddHandler in VB to add my own method to the Click event :
AddHandler Button.Click, AddressOf myButton_Click
I see that my code executes last - after other event handlers for the Button_Click event. Is there a way to insert my event handler in front of other events so that it executes first?
I have a public variable which seems to be going out of scope. I am confused as it has been dimensioned as a public variable: Public xlCell as As Microsoft.Office.Interop.Excel.Range
I originally had all my code in the same module in the same project and it was wrapped within a For/Next Loop (Example 1). I decided to clean up my code and make it more modular (Example 2). All the code is still in the same module in the same project.
Upon doing so, my public variable is not recognized in any of the private subs that I have created. I keep getting the following error: Message="Object reference not set to an instance of an object." When I test the variable using ?IsNothing(xlCell) in the Main Sub I get False in the main sub. this tells me te variable is recognized. However as soon as the Call SelectCaseSub() is triggered, I get a True value for ?IsNothing(xlCell). Why is this? Shouldn't this variable be in scope regardless?
Trying to understand the best way to do this and I'm can't get it figured. Here's basically what I have:
Public Class CardParsingClass Private iAcctIDStart as integer Private iAcctIDLength as integer
[code]....
I've only included 2 of the class level fields here but there are actually 30, so that's why I was hoping to be able to send the name of the field to set and the value to set it at in the SetValue function. So in some other routine in the program I'd like to be able to issue the following call:
SetValue("iAcctIDStart", "3")
But then when I get into the SetValue routine, I'm not sure how to proceed. I thought about a case statement that would basically be this:
select Case strFieldToSet case "iAcctIDStart" iAcctIDStart = cint(strValue)
I come from C# (use VS 2005, .NET 2) and I know that when I declare a private variable I can "extract" from it the corresponding "property". In VB.NET I've declared a lot of properties (in the diagram class designer). Now am I forced manually adding the corresponding private fields?
How to access a variable that is located in a private sub and then display that variable in another private sub located on the same form.
My actual code is: Public Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click Dim strFileName As String strFileName = OpenFD.FileName OpenFD.InitialDirectory = _ [Code] .....
Obviously, the sub in blue has nothing in it currently and so this is the one I would like to access the variable in. The variable I want to use again is 'FILE_NAME'.
I don't know if this has been asked before, but we're having a discussion about it today at my job. Should private variables (that are shared/static) be instantiated when they are dimensioned/defined, or is it a better practice to do this inside of a constructor?
Public Class IpCam Private Const HOST As String = "http://test.com/url/example" Private Shared _Example As New OurClass(HOST)which one to use?
I am planning to use a shared variable to implement a logging facility. Have a look at the code below:
Imports System.IO Public Class TestClass Public Shared objError As New StreamWriter("C:Test.txt") End Class
[Code]....
I think I have found my answer here: [URL] "A static variable continues to exist and retains its most recent value. The next time your code calls the procedure, the variable is not reinitialized, and it still holds the latest value that you assigned to it. A static variable continues to exist for the lifetime of the class or module that it is defined in."
I am not convinced that this is the best way to create a logging facility.
When I've used the remove handler method in my code, I get this warning:The 'AddressOf' expression has no effect in this context because the method argument to 'AddressOf' requires a relaxed conversion to the delegate type of the event. Assign the 'AddressOf' expression to a variable, and use the variable to add or remove the method as the handler.Why do I have to assign the "AddressOf" expression to a variable?
Is it possible to determine using VB.NET whether a certain event has any handlers attached to it? I don't own the event, in this particular case I want to know which of the items in a Windows.Forms.MenuStrip have their ToolstripMenuItem.Click event handled.
I've been looking for a solution to this for several hours now and cannot find a solution.
The Scenario:I have a masterpage baseclass (called basemaster)All of my master pages inherit from basemaster basemaster defines an event 'Public Event HandleClickEvent As EventHandler'I have a masterpage named master1 master1 defines an event handler 'Public Shadows Event HandleClickEvent As EventHandler'master1 has a user control named usr1 usr1 has a button that raises event ButtonClicked when clicked I have a page (thePage) that uses master1 thePage has a button click event handler that it registers like so: 'AddHandler Master.HandleClickEvent, AddressOf HandleTheClick' master1 has code something like:
Protected Sub Usr1_ButtonClicked(ByVal sender As Object, ByVal e As System.EventArgs) Handles Usr1.ButtonClicked RaiseEvent HandleClickEvent(sender, e) End Sub when thePage loads I see it register the handler on master1 when the button is clicked, Usr1_ButtonClicked is fired and I step through the RaiseEvent but HandleClickEvent on thePage is never reached.
how to add one event handler name clearallboxes that handles the TextChanged event for both examples(Customer text box and Total text box ) This event handler should clear the values in the text boxes that display the results.
i have a page which dynanically create a link when it load, after i click on the link it should loop in the database fetch all the record and display another set of link , then when i click on these link it should give me all information about this particular record it like this one
Q: when the page loads, it creates the first link which is associated with an event handler, it fire the first event handler (Getname) but it not firing the second event handler (GetnameDetails)
Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init If ViewState.Item("nameload") IsNot Nothing Then If ViewState.Item("nameload").ToString = "True" Then
I have a form that is derived from a base class. When the form is created a behavior class is also generated that handles event management, bindings, etc...I create a form instance(FormFoo). When the associated behavior class is created it has a method in it with a signature of: grid_EventA(....) Handles grid.eventA
I want to handle EventA in FormFoo instead of the behavior class so I remove the handler that was generated in the behavior class and add a handler that points to a method in FormFoo. This all works just peachy. The event is properly handled in FormFoo only.
Next I instantiate a modal form(FormBar) via a button click in FormFoo. I then close FormBar. Now we have a problem.When eventA fires it is now handled from the Event handler in FormFoo AND in the behavior class associated with form foo(bad).Is the event handler in the behavior class(grid_EventA(....) Handles grid.eventA) getting resubscribed when the form gets focus again? I don't understand how that event is getting resubscribed.
I figured it out I removed the Handles grid.EventA from the method signature:
grid_EventA(....) Handles grid.eventA
Then I added the handler during initialization of the BehaviorClass using:
AddHandler grid.EventA, AddressOf grid_EventA
Once I did that the problem went away. It appears that when you use MethodName(..) Handles that the event bindings get reset when the control comes back into focus.
public event EventHandler Trigger; protected void OnTrigger(EventArgs e) {
[Code]....
Is there a way to do this in VB.NET? Test for null I mean?
MORE INFO
I forgot to mention. I have classes written in C# but I am writing my unit tests in VB.NET.
I am trying this in the unit test...
If myObject.Trigger IsNot Nothing Then ''#do something End If
This is causing a compile time error which says ... "Public Event Trigger is an Event and cannot be called directly. Use the RaiseEvent statement to raise an event."
