VS 2008 Removing Handlers Associated With A Method?
Jun 8, 2010
in my class i have a user defined event and i use the addhandler clause to link the event to a methodAgain this is for a download manager application im working on, and like download managers when u select an item (a download task) from the listview you want its thread log to show and be linked to the thread log so that every time the download task has new information it will be updated directly on the thread log.So addhandler clause worked perfectly for this. But now the problem im having is with removing the handle from previously selected tasks.
i am finding it hard to remove the event handle of the previously selected download task when a new download task gets selected because the previously selected task is variable. I can add a public dimension which corresponds to the previously selected task and that way be able to remove the handler everytime a new job is selected, but it seems abit sloppy to me. Actually i have other events specific to when each thread in a download changes so to remove those handlers i would need an array of the previously selected threads (and that seems even sloppier).
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Apr 2, 2009
I have two forms, A and B. A shows B modally. B can exit normally, or can exit because of an exception. Therefore, I have this code in a method in A:
Dim nf as New B
Try
nf.ShowDialog
Catch ex as Exception
'Whatever
End Try
Now, B has some event handlers that handle an event that is raised when a certain value changes. I just found out that if B exits because of an exception, rather than a normal exit, the event handlers are still hooked up. To figure this out, I added a private string variable, and in the constructor of B I added a line to put a GUID.NewGuid.ToString into the variable. When I run this, I can pause in the event handlers I mentioned earlier, and look at the private variable to tell which instance of B is actually handling the event.
Under normal operations, there is only one instance of B. However, if B exits due to an exception, I find that the instance of B which died due to the exception, handles the event before the new instance of B is even created. At a slightly later date, the user presses a button that will cause the event, and, due to something hard to explain, the event gets raised six times, three each from the old, undead, instance of B, and three times from the new, visible, instance of B.
I think that the entire problem I am having is that the event handler is triggering things that cause the two instances to pinball events back and forth between the two of them in a complex recursion. My problem is how to get rid of that undead instance of B so that it stops handling the events that are raised. I tried putting nf.Dispose in the Catch handler of the above snippet, but that did nothing.
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Aug 1, 2009
I created a custom class which creates a PictureBox.
The Class looks like this:
Public Class Layer
Dim pb As New PictureBox
Public Sub New(ByVal parentPB As Panel, ByVal parentContex As ContextMenuStrip)
[Code]....
How do I add event handlers to this picture box?
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Jun 16, 2009
to know if a control have any handler. I have a dgv and in the editing control Showing event i add an event handler like this: VB AddHandler e.Control.KeyPress, AddressOf Grid_KeyPress_NumbersOnly This event it's added in some of the columns and for the other ones i remove it... The problem it's when the user, for example selects 3 columns where the event it's added, then if the user selects one where the event it's removed, it doesn't remove all handlers... So i have 2 solutions, when removing i put multiple removes or the other check if the event handler it's added doesn't add again. I prefer this second option, but i don't know how to check if the event it's added?
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Jan 28, 2009
i want to automatically add all the events of the activeform under try catch block.i am using a simple code which puts the selected code of ActiveDocument under try catch ( using DTE.ActiveDocument.Selection )i have to manually select each event's code and apply the macro, which does not seems to be a very good idea.
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Mar 6, 2011
is it allowed to use more than one Sub to handle the same event ? For example , may I have 2 separate subs to handle the Load event of a form ? Will they fight each other ?I have tested it and it seems to work fine , nevertheless I thought I'd ask you . In case you wonder , there is no great deal , I just want to copy the same lines of code in more forms so I am doing it just in favor of the looking aspect .
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Oct 19, 2010
Consider a MyForm class that contains a shadowed implementation of Show(). It also contains a CreateForm() method, which accepts an instance of the form and calls the shadowed sub:
[Code]....
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Oct 21, 2009
How would I remove certain text from a textbox? I want it to be something like this.
Dim NewText as String = TextBox1.Text.Remove "1" Also, if there is no text, how can I keep it from crashing?
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Aug 20, 2009
How do i remove all the items from the combobox?i triedVB.NET omboBox1.Items.Remove(ComboBox1.Items)
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Aug 31, 2009
I have a button that when pressed I want it to remove all the ending urls that have ending with / just to remove / item on the end so it will live me a url with out / on the end if u know what I mean. [Code]
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Dec 25, 2009
Is it possible to put a label on a form and automatically have it removed after a certain date?
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Feb 16, 2010
I am using the follow code to obtain source code from my site:
Dim downloader1 As New Net.WebClient
Dim source1 As String = downloader.DownloadString("[URL]")
But there is code in the file which I am loading, something like:
<!-- load time: 0,05ms -->
<!-- Queries: 25 -->
But I want to remove all the <!-- --> lines from source1.
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Aug 2, 2009
I'm wondering what the proper way to remove an item from an array is. The way i am doing it at the moment is:MyArray(0) = NothingIs this the best way to do it as i'm having problems with my programme and i think it may be something to do with this
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May 26, 2009
I have two text boxes with a word in each. I am trying to remove both these words from another textbox.
so say for instance
textbox1.text = helllo
textbox2.text = world
[code].....
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Jun 12, 2011
I Put together this bit of code. What the problem im having is Removing a Label after i place the code its in a select end slecte code . The Problem is in red.
the code
Dim Animals As String = (TextBox1.Text)
Select Case Animals
Case "Apples"
[Code].....
Everything works Accept the remove selection ... I think it has something to do with Dim LB As New Label() ... And ... Me.Controls.Remove(LB)
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Mar 24, 2011
I have 3 list views: (steps)
1...One column listview_AllAddresses, read from several .txt files containing email addresses (creating a list with duplicate entries)
2...One column listview_RemoveFromList, containing email addresses populated by textbox add or drag and drop from listview_AllAddresses (working)
3...One column listview_DuplicatesRemoved, where final list is to be diplayed without duplications entries and (no code yet) items from listview_RemoveFromList removed as well
4...Write to a .txt file containing adjusted list of email addresses
Private Sub Button_ImportSource_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button_ImportSource.Click
Try
OpenFileDialog1.Reset()
OpenFileDialog1.Filter = "txt|*.txt"
[code]....
Results are that I get is an exact list moved from ListView_AllAddresses to ListView_DuplicatesRemoved.
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Oct 17, 2009
I have a textfile called Set.txt and what I want to do is to remove all multiple chars in the file.[code]I figured this is possible to do either checking for double letters and running a loop or maybe some regex, but i would like to know what you think the best way of doing this is.
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Sep 28, 2009
I first noticed this problem using C#, but I thought at that time it was something that did not happen in VB, so I posted a similar question in the C# forums. I never saw it happen before, but it seems it does happen in VB too, so I decided to post the question again here in the hope that VB at least has something that helps me..The problem is that I have many (around 30) instances of a custom control on a Form. The custom control is just a class inheriting from Panel with some new properties. I decided to create two BackgroundColor properties (1 and 2) to allow for gradient backgrounds. I'm not sure if this matters, but I simply left the second BackgroundColor property empty (never initialized it), because I was not using it yet.After placing around 30 instances no my form, all in different levels of nesting in different FlowLayoutPanels (took me an hour at least to get everything right), I tested it out and decided it looked ok, and it didn't need a gradient background color after all.So, I went in the custom control code and simply deleted the second BackgroundColor property.The result was 30 errors in the form's Designer.vb file. It seems each control was still trying to set the property (to Color.Empty), but obviously could not find it.I could no longer access the form's design view, except if I click the 'ignore' button and lose all the controls.
Is there no way I can 'safely' remove a property from a control that is already on a form, so that the designer file updates itself accordingly and no longer tries to set the removed property?It seems foolish that I have to remove the 30 errors (actually 120, because I still need to remove 3 more properties) manually from the designer file, when I know the editor is perfectly capable of finding all references to some name and for example renaming them (the context menu Rename function), so why not delete them?I am sure I'm simply missing something basic here that I somehow never learned and never needed before in 2 or 3 years of using VB.NET.If not, do I really have to remove 120 lines manually, each hidden deep in the designer code in different lines?!I know I could simply remove all controls and re-add them, that would get rid of the errors, but it will take me forever to set them up again correctly, including the events etc..
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Feb 19, 2009
I first noticed this problem using C#, but I thought at that time it was something that did not happen in VB, so I posted a similar question in the C# forums. I never saw it happen before, but it seems it does happen in VB too, so I decided to post the question again here in the hope that VB at least has something that helps me...
The problem is that I have many (around 30) instances of a custom control on a Form. The custom control is just a class inheriting from Panel with some new properties. I decided to create two BackgroundColor properties (1 and 2) to allow for gradient backgrounds. I'm not sure if this matters, but I simply left the second BackgroundColor property empty (never initialized it), because I was not using it yet.
After placing around 30 instances no my form, all in different levels of nesting in different FlowLayoutPanels (took me an hour at least to get everything right), I tested it out and decided it looked ok, and it didn't need a gradient background color after all.
So, I went in the custom control code and simply deleted the second BackgroundColor property.The result was 30 errors in the form's Designer.vb file. It seems each control was still trying to set the property (to Color.Empty), but obviously could not find it.I could no longer access the form's design view, except if I click the 'ignore' button and lose all the controls.
Is there no way I can 'safely' remove a property from a control that is already on a form, so that the designer file updates itself accordingly and no longer tries to set the removed property?It seems foolish that I have to remove the 30 errors (actually 120, because I still need to remove 3 more properties) manually from the designer file, when I know the editor is perfectly capable of finding all references to some name and for example renaming them (the context menu Rename function), so why not delete them?
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Apr 2, 2009
I have a table with many values inside of it that might have single quotes around them. I need to create a duplicate table without those single quotes. I can't modify the original table as I need to use it, 'as-is' later.
I've done this with a table.Clone and using a foreach to loop through the rows and columns removing single quotes as I need and then putting that new row into the new table. It works and it's straight forward.....but
I'd like to do the same thing using LINQ. This was my attempt....
Dim myResults = From myRow In dtTable _
From myItem In myRow.ItemArray _
Where TypeOf myItem Is String AndAlso _
myItem.ToString.StartsWith("'"c) AndAlso _
myItem.ToString.EndsWith("'"c)
As you can see - I didn't get very far. I had trouble finding examples that weren't looking at a specific column in the DataRow. It looks like my code does pull back all the matching results - but I'm at a lose for how I can create a duplicate table/modify the values.
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Dec 14, 2009
How would I remove files that are already added into the listview?
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Nov 10, 2009
I have a userform which allows my users to go through numerous comboboxes to select a combination of items they want displayed in a datagridview. My datagridview is populated from sql queries to my database(s), depending on the choices made in the comboboxes. The first column has checkboxes so my user can pick which rows they want to keep. Once they've chosen what they want, they click a button to save those rows into a seperate sql table.
All this works well, but here's my problem. After they click the button to save to the table, or another button which simply clears the datagridview without saving to the table, I want to clear my datagridview. While it seems to work, after all my comboboxes are cleared, and I go through another iteration of choices, and I display all the rows again in the datagridview, I get a second column of checkboxes.
Right now the checkbox column is added right before the datagrid's datasource is set. I've tried adding this column outside the subroutine that populates the grid, but it doesn't work.And I've tried numerous ways to delete this column so it will be regenerated when the datagridview is repopulated. Different things either give me errors or bomb when I compile.how to remove a checkbox column from a datagridview for good?
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Nov 8, 2009
suppose I have the following hirarchy:
Public Class PrimalClass
Public Event SomeEvent()
End Class
Public Class BaseClass
[code]....
this code compiles and runs.what I want to do, is remove the event SomeEvent in BaseClass so that DerivedClass won't be able to register a handler to it.
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Apr 5, 2009
Whilst playing around with DataGridViews in VS I've accumalated quite a few TestDataSets within my project.
Can someone please tell me the correct way of removing these cleanly? At the moment I've been Right Clicking a DataSet (from within Solution Explorer) and either clicking 'Delete' or 'Exclude From Project'
Doing this throws up Errors in the Error list such as;
TestDataSet is not defined
TestDataSetTableAdapters is not defined
TestDataSet is not defined
TestDatasetTableAdapters is not defined
I then double click each error in turn which takes me to the actual code with the error and delete this.
I have quite a lot of TestDataSets and I'm hoping there is another way to do this much cleaner.
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Dec 3, 2009
I need to add a reference for excel. But to do that i need to remove an earlier version i added.
How do i remove what i have already added so i can add another version?
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Jun 12, 2010
I've searched on the Internet and I can't find a solution to this simple problem. I've also looked on Microsoft's MUCH improved MSDN site and haven't found a solution, so here it goes. I'm trying to remove an entry from a list of class and it doesn't get removed. Here's a sample of the code I'm trying: (I renamed the class and variable names to make it a simple example)
Dim lstClass As New List(Of TheClass)
Dim mClass As TheClass
I tried this first
mClass.filename = "The Entry to Delete"
lstClass.Remove(mClass)
[Code]...
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Nov 30, 2009
I'm trying to build an app that would search a text file for a string entered by the user, and delete the line of text containing that string. Here's the code I have. The code works, but since I'm relatively new to VB and programming as a whole, I was wondering if there's a better method out there. he strFilePath is handled by the openfilediaglog
Dim strSearch As String = Replace(MaskedTextBox1.Text, "-", "")
Dim strLine As String = Nothing
Dim strAllText As String = Nothing
[code].....
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Jul 5, 2009
why my code isn't deleting the selected row in my ListView from my SQL table? it says it works fine in run time and removes the seleced row from the ListView but when i restart the program its there again.
Obviously this is because my code isnt actually deleting the data from the SQL table but i cant work out why not? the code for my delete button is as follows
Private Sub btnDeleteTask_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDeleteTask.Click Dim delete As DialogResult = MessageBox.Show("Are you sure you want to delete this customer?", "Delete Customer", MessageBoxButtons.YesNo, MessageBoxIcon.Warning)
[Code]...
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Nov 24, 2009
I have a byte array with contents from a file in it, but I want to trim / remove the first element from it [byte(0)]. I've searched for days and experimented with a hundred different methods but they don't work.
[Code]...
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Dec 18, 2010
I've got a webservice and the WSDL file it pointing to a local file for testing reasons, is there a way of changing this when deploying my app without removing and readding them all?
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