how do we implement Finalize to remove an object?i tried this:
Public Sub kill()
Me.Finalize()
End Sub
then this:
Dim g = New Test
g.kill()
MsgBox(g.ToString)
weird the object still exists, i don't get a NullReferencePointer exception
Class ComponentsContainer ' a component contains other components'
Inherits System.ComponentModel.Component
Private foo as New Component
Private bar as New Component
Protected Override Sub Finalize()
foo.Dispose() ' HERE ? '
bar.Dispose()
MyBase.Finalize()
End Sub
Protected Overrides Sub Dispose(disposing As Boolean)
[Code]...
I am able to populate an object and output everything. How do I remove say the name2 object?
la.Remove(Logins("name2")) doesn't seem to work.
Private Sub btnListArray_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnListArray.Click
[code]....
in my datagridview, i have a column where, depending on values in other columns, I declare a new DataGridViewImageCell, set the image and then attatch it to the grid (brief example below):
Dim cell As DataGridViewCell = New DataGridViewImageCell
Dim img As Image = imgList.Images("comments")
Dim i as Col = 1
cell.Value = img
grdHeldOrders(column.Index, i) = cell
When i click on the column header in question to sort, I get the exception "At least one object must implement IComparible". I kind of guess this because certain cells are different types but I'm not sure how to get around the problem and where to implement IComparible. Does anybody have any examples?
I am declaring an IList:
Dim OrigVendors as IList
OrigVendors = new List( of IVendors)
I populate the OrigVendors variable and what I want to do is find all the objects that have the ID I am looking for. Then I need to update a property on that object for only the ones found. Is this do able with an IList or do I need to use some other type of collection? I am using VB.net.
I've now properly started implementing OO into my system (which I probably should have done from the start) but I just want to clear some best practices.So let's say I have a class called Job which contains information such as Description, Project Manager (Employee class), Value etc. at the moment, if I initialise the Job class it will initialise all the information held within it, even if I only want the job description. Is it best practice to do this or is it better to implement the class and access the database for values as and when they're needed? Or is it just better in those cases to just access the database directly?
View 1 Replies(1) I've read a lot of questions about IDisposable where the answers recommend not using Finalize unless you really need to because of the process time involved.What I haven't seen is how much this cost is and how often it's paid. Every millisecond? second? hour, day etc.
(2) Also, it seems to me that Finalize is handy when its not always known if an object can be disposed. For instance, the framework font class. A control can't dispose of it because it doesn't know if the font is shared. The font is usually created at design time so the user won't know to dispose it, therefore finalize kicks in to finally get rid of it when there are no references left. Is that a correct impression?
when i call GC.ReRegisterForFinalize(obj) and changed my mind, i could call GC.SuppressFinalize(obj) and remove it from the list of object that requests finalization. problem is that when i call GC.ReRegisterForFinalize(obj) twice, it registers the object twice in the finalization-listing. i need to remove the object from the finalization-listing but multiple calls of GC.SuppressFinalize(obj) could not remove obj from the list.also, why is it acceptable for this function to be called SuppresFinalize when after calling it Finalize still occurs?
View 2 RepliesI'm looking at some vb.net code I just inherited, and cannot fathom why the original developer would do this.
Basically, each "Domain" class is a collection of properties. And each one implements IDisposable.Dispose, and overrides Finalize(). There is no base class, so each just extents Object.
Dispose sets each private var to Nothing, or calls _private.Dispose when the property is another domain object. There's a private var that tracks the disposed state, and the final thing in Dispose is GC.suppressFinalize(Me)
Finalize just calls Me.Dispose and MyBase.Finalize.
There are no un-managed resources, no db connections, nothing that would seem to need this.
I have a logging class that stores entries in a datatable dt. I then use SQLBULKCOPY to write that dt out to a sql table. Basic stuff. Problem is, I'd like to only call SQLBULKCOPY when there's say 50 entries in the dt. The problem is, what if I'm done (either intentionally or not, like if the code block that's using the log class throws an exception) with the logging object and there are still 15 rows in the dt?
View 1 RepliesIs there a way to Finalize() or Dispose() a Module in VB.NET? Have a situation similar to the following and need to Dispose() itsUnManagedObject.[code]...
View 2 RepliesI am comparing an alternative Dispose pattern to VS2005's default implementation. In doing the comparison I have found several uncertainties with the default pattern which have raised a handful of questions related to sub-class implementations and object Finalization.
[Code]...
why does finalize not get fired when i try to destroy a class until the application is exiting. i feel like because these objects were never actually finalized until the program is exiting that its somehow bogging down the operation of my app VS 2008?
View 1 RepliesGood example using the List(T) object. I need to be able to add and remove items from it.
View 7 RepliesI am writing a app and I have a treeview. This treeview gets populated with parent and children. I also have a panel and a picturebox with a image in the picturebox. On top of the picturebox I and writing some Graphical objects.
See code
Dim theG As Graphics = Graphics.FromImage(PictureBox1.Image)
Dim ComputerName As String = ""
Dim UserName As String = ""
Dim NodeIP As String = ""
[Code] .....
When Afterselect on the treeview item this code runs. However when I select another child/node the code runs again whcih is great it write over the top on the previous text. What is the command or how do I clear/delete/remove the theG.drawStrings from the first AfterSelect from the treeview so the new drwstrings are clear.
Is there a simple way to remove Objects from a List by using a specified value?I add 2 persons to a List, how can now I remove a person by a name without using any Loops? (if possible)
[Code]...
I've been searching and trying out code all day.Nothing errors on this code but it doesn't delete any user accounts.[code]...
View 8 RepliesI would like to overrides the datetimepicker object to remove the texte when the property _clearOnDisabled is true. When _readOnly property is true, I would like to show the text in black not gray. So I tried with WndProc but I seem that every single object go through my function not only my datetimepicker. I get 100% CPU when I put the WM_PAINT message. I also tried to overrides the OnPaint but its not getting in.
Imports System.Drawing
Imports System.Windows.Forms
Imports DTP.WindowsMessages
[code]...
I am considering a piece of code that will manage access to a collection object from multiple threads - add, update, remove, clear. OK ... so I have put a sync lock within each method, but what is not clear from the MS documentation is exactly how the sync lock is behaving. Is it locking the piece of code it wraps? Or is it locking the object? And if it is locking the object a private static object should lock out any code locked on the object within all instances of the object? i.e. if an add operation is underway, an update, delete or clear will wait for the lock to be released.
Finally, if I have multiple threads contending for the sync lock, how is the release managed? First come, first serve? random (from my p.o.v)? Is there a chance that two separate threads could blunder into 'locked' code simulataneously?
I'm making a control and I am trying to finalize my design time properties grid. I have several List(of Class) items as public properties and when I click on the design time menu (while testing the control) there is the word "Collection" and a button with an ellipsis (...) that brings up a neat pop up with the buttons Add/remove and all of the public properties of the collection's class on the right hand side. Basically for a non-collection instance of a class (with public properties) I'd like a similar button to show up. I know I could put all of the properties in the main control class and group them, but I like the pop up box feature. Anyway to duplicate this? (think font grid item etc.)
View 3 RepliesJust had to remove remove statics and use Delegates refering to class. i have got a little problem in one of my project.I need help to resolve it.My application Connect several FTP server with the same Class.I'm using TCPclient for few specifics Commands.The problem : All threads call the same TCPclient wich can't connect several server at once.I would like to create a New TCPclient for each thread.
[Code]...
I'm trying to remove individual nodes from their parent, I tried the Remove method but it doesn't seem to be working. How is this done? Is this a bug or what?
Sub Main()
Dim xml =
<?xml version="1.0" encoding="utf-8"?>
[Code].....
I am somewhat new to object oriented programming and am attempting to flatten a Linq object hierarchy by using a shim class.how to initalize a derived class with property values from a base class?I have two objects, a base object with about 100 properties, and a derived object which inherits from the base object and adds a few additional properties beyond those of the base object. My simple constructor creates the derived object, but I am looking for a way to initialize the derived object properties with values from the base object.Right now I am using reflection to iterate over the properties individually and I suspect there may be a better way. The following example shows my shim class constructor for the derived class, and two properties:
newProperty1 - a new string property of the derived class
flattenedProperty2 - a new string property of the derived class, copied from a 2nd-level object of the base class
Code example:
Public Class derivedObj
Inherits baseObj
Private _newProperty1 As String[code].......
Is this the correct constructor approach to flatten the object hierarchy using a shim class? My second question relates to initialization of properties in the derived class. The constructor above creates the derived object, but what is the best way to initialize the derived object properties with values from the base object? The following code uses reflection to iterate over the properties individually, but I suspect there may be a better way.
Code example:
' property names are in the string array fieldNames
'baseObjQuery is an ienumerable of baseObj
'derivedObjList is a list of derivedObj[code].....
Is there a simple way to initialize values for the properties in the derived object based upon the values of the common properties in the base object?
How can i remove an array item by selecting an item from listobx and press remove/delete button?for an example, if i want remove index 2 from listbox, so the array should remove index 2 item and move the item of index 3 to index 2 and so on.
View 7 RepliesI'm trying to get a ComboBox to remove the 6th string in the ComboBox or an index of (5) but it doesn't remove it here is the function I am using:
if ComboBox1.items.count = 6 then
ComboBox1.Items.RemoveAt(5)
End If
I am getting following error whenever I want to use IIf function inside entity framework query.
LINQ to Entities does not recognize the method 'System.Object IIf(Boolean, System.Object, System.Object)' method, and this method cannot be translated into a store expression.
why the code...
Form1.Controls.Remove(myCustomControl) ...does not remove the control.
Because whenever I remove a control and add it again, it does not Load but rather just changes its visibility from false to true and all the variables are not reloaded.
I tried to use .Dispose() but VB.net tells me thatit can't access a disposed object whenever I try to add the control again.
What do I need to convert?
Dim CEESearchByAppNo = From CEEsearch In dbCEE.tblScanneds _
Where CEEsearch.AppNo = iAppNo
[code].....
How do I calculate the direction an object is facing in degrees, if object A is at x1, y1 and facing object B which is at x2, y2?
View 2 RepliesHow to implement such a feature in vb.net??
View 3 Replies