C# - Pattern For Managing Reference Count And Object Life
Mar 18, 2010
We have a serial port which is connected to hundreds of physical devices on the same wire. We have protocols like Modbus and Hart to handle the request and response between the application and devices. The question is related to managing the reference count of the channel. When no device is using the channel, the channel should be closed.
I have recently created an application to play videos using theAxWindowsMediaPlayer object. I was able to set good part of the controls but I'm still struggling with the audio track functionality. In order words, I was not able to find a method or even a property that allows me to select which audio track should play with the movie. If the movie has more than one, the audio tracks are played all together when the play method is executed.
Iam maintaining a large code base I have inherited (ported from vb6 to C#.net 1.1, then to .net 2.0/c# and so on). I have this scenario.My main project references two DLLs - DLL-A and DLL-B
DLL-B references DLL-A. Both dll's and my main project are in 3 separate namespaces.
1) Are 2 copies of DLL-A being loaded in memory ? (dll ref count)
2) How do I find out how many copies of a .net dll is loaded in mem ? (which tool is normally used)
Is there a way to iteratively reference an ASP.NET control based on it's name pattern? Perhaps by a "pointer" or something?What I have are a large set of comboboxes (each with an associated DropDownList and TextBox control). The DropDownList always has an item selected by default, but the use may wish to submit a NULL value. I come up with the following code to handle three cases: NULL, Existing Item, New Item.
'TextBoxControl & DropDownListControl should iteratively reference their ' respective TextBox & DropDownList controls by the actual control name
[code]....
The problem is, with so many comboboxes, I could easily end up with hundreds of lines of code. I wish to handle this in a more dynamic way, but I do not know if it is possible to reference controls in this way. Say I wanted to reference all the TextBox Controls and DropDownList Controls, respectively.
I can do string formatting with a given naming pattern to generate a name ID for any of the controls because they are all named with the same pattern. For example by attaching a specific suffix, say "_tb" for TextBox Controls and "_ddl" for DropDownList Controls:
Can this sort of thing be done in VB? Ultimately, my goal is to take the value entered/selected by the user, if any, and send it to a stored procedure on SQL Server for insertion into the database.
The book "Beginning ASP .NET 4 in VB 2010" contains the following:NOTE: TaxableProduct inherits from Product.You can also cast in the reverse directionfor example, cast a Productreference to a TaxableProduct reference. The trick here is that this
Private Sub SpellChkMenuItem_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles SpellChkMenuItem.Click Dim activeRichTextBox = TryCast(Me.ActiveControl, RichTextBox) 'clsFS.CheckSpelling(activeRichTextBox)[code]....
When I am in the rtb and click on spell check button it tells me the error "Object reference not set to an instance of an object." On this line
SpellChecker.Text = activeRichTextBox.Text
But it is suppose to be getting the focused rtb correct? So why is it not referenced
I am receiving this error: Reference to a non-shared member requires an object reference on the code I've bolded within the code body. Here is my code:
I get this error:Reference to a non-shared member requires an object reference.When i compile on the following code section:
Private Sub statusBarToolStripMenuItem_Click(ByVal sender As Object, ByVal e As EventArgs) ToolStripMenuItem.Checked = Not ToolStripMenuItem.Checked statusStrip1.Visible = ToolStripMenuItem.Checked
I have written a base class from which I wish to derive several child classes (in this case Windows Form classes), and I'm using a Factory pattern in order to maintain a collection of the child instances, so that a form can only have one instance per primary key value. (sort of a mash-up of Factory and Singleton patterns.)
I'm using the following code in the base form class[code]...
I am opening frmB (variable for FormB - the actual form) from frmA. From btn1 I open frmB like this:
frmB = New FormB() frmB.Show()
From btn2 (frmB is already open) I bring frmB to the front from behind frmA:
FormB.Show() FormB.BringToFront().
No problem so far. Now I need to pass an arg to frmB. This is where I am having the problem.
from btn1 (in frmA) I do this:
frmB = New FormB(myArg) '--pass myArg to constructor of FormB -- no problem here frmB.Show()
then from btn2 -- this is where I have the problem
FormB.Show() FormB.BringToFront()
I tried placing myArg in FormB.Show(myArg) but that did not fix the problem. What is the correct way to pass myArg to FormB (frmB) in this scenario? Do I need to share FormB or frmB? How do I do this? "frmB" is frmA level variable.
why i am getting an "reference to a non-shared member requires an object reference" error on format.Yesterday gets the previous days date and presents it in a yyyyMMdd format.vsettlementDates takes the "Yesterday value and requests data from it.
Dim Yesterday As String = format(Today.AddDays(-1), "yyyyMMdd") Dim vSettlementDates As String = (Yesterday)
Error 1 Reference to a non-shared member requires an object reference. (on WindowsIdentity.Groups)
Here's my code from that uses the WindowsIdentity.Groups property to display the identity references for the groups the current user belongs to. This code is part of a larger example provided for the WindowsIdentity class.
Public ReadOnly Property Groups As IdentityReferenceCollection Get Dim irc As IdentityReferenceCollection
I have the following code below, how the line where it says : For Each c As councillor In councillorList i get the error: reference to a non shared member requires an object reference. Can someone please advise where i am going wrong? [Code]
Alright, so im getting this error:Reference to a non-shared member requires an object reference.This is the bit of code the error is pointing to:My.Settings.Bookmarks.Add(WebBrowser.Url.ToString)Why is it giving me this error?Its saying WebBrowser.Url is the problem.
im sure it is something really simple. Im by no means comfortable with VB. The below code is not mine but i have altered it for my needs. However im getting a couple of errors.
Reference to a non-shared member requires an object reference. I have underlined the errors in the code and they all refer to the above description
Im trying to create a login page which accesses a mysql database I keep getting this error: reference to a non shared member requires an object reference
I am getting the following error when I call another form from Form1 and fill out the text boxes and Press Ok button. For some reason I cannot access the datatable (dt) from Form1. It gives me the following error: Reference to a non-shared member requires an object reference
I have added one class under namespace BusinessLogics. I have inherited System.Web.UI.Page to class and showing error as 'end expected' in System.Web.UI.Page
Namespace BusinessLogics Public Class BllUploadImages Inherits System.Web.UI.Page End Class End Namespace
I'm getting this message in the IMMEDIATE window when I try to look at the value of public variables from my main form.[code]Reference to a non-shared member requires an object reference.But it steps into the IF statement without error - so the boolean is TRUE.
i'm using this add reference of a certain software to the libraries of VB it doesent work.i just recently notice that the zenon. application. projects. item("fdgdgd"), give this coment "reference to a non-share member requires an object reference"
This is the first time I made a DLL file (talk about being obsolete). So I made this dll file containing all functions I need for Input Handling, I named the file "CommonTools" and added an "InputHandling" Class on it... I then created a new project, added "Common Tools" as a reference and made this code for my main form to test it: