Add Item To Generic List Change Value Of All Previous Added Items To Last?
Oct 27, 2010
I'm writing code some that is supposed to be creating a list of objects pulled from a data base. The list returned has every item containing the value of the last one added. When I debug the code is VS2008 I can see each time that the list.add is performed every other item in the list being changed to the one just added. Here is the code I running. The line containing ListAKAs.Add(itemAKA) is the one where the entire list of objects is changed to be identical to the one just added.[code]....
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Jun 19, 2009
I have several custom classes in a VB.NET (VS2008) project which are related to each other through generic list collections. The lower tier classes refer directly to some of the parent classes (to make it easier to refer backwards up the chain). My question is, is it possible to add the reference to the parent class when the item is added to a collection, when that collection is a property?
Below is some sampling of code to illustrate.
Public Class FlexServer
Private m_FlexLicenses As List(Of FlexLicense)
Private m_Modules As List(Of FlexModule)
Public Property FlexLicenses() As List(Of FlexLicense)
[code] .....
In the code above I have the FlexServer class which refers has two lists as properties, one for FlexLicense and one for Modules. The FlexLicense class has a property to refer back to the FlexServer class that "owns" it. In order to update this property in code, I have to add the FlexLicense to the FlexServer.FlexLicenses list AND set the FlexLicense.FlexServer property. What I am looking for is, is there a way (in the property definition or wherever) to both add the item to the list and alter it at the same time?
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Nov 29, 2010
I have an XML node which I am adding to a generic list of xml nodes:
ListXml.Add(myXmlNode)
Now whenever I change the node afterwards, all members of the list turn into copies of the node. Why would the list keep track of this and more importantly how am I supposed to 'detach' my work node from that list?
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Mar 23, 2011
Public Class notifierMain
Public Class Contacts
Inherits List(Of row)
Public Sub New()
[code]....
When I debug this winforms application I get curType = "notifier.notifierMain+Contacts+row" I want to the Validate function to know it is in MyContacts. How do I do this?
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Oct 1, 2009
I'm looping all the properties in an object via reflection:
For Each p As PropertyInfo In values.[GetType]().GetProperties()
If p.CanRead Then
'Do stuff
End If
Next
how to determine whether the property in question is a generic List(Of T)? If it is I need to loop the list itself.
I've experimented with GetType and TypeOf but have not managed to get anything working.
To clarify, I want to keep this generic. I do not want to specify the type of T, I need to loop the list items and call the ToString method on each item. T could be one of a number of different types (application specific reference types). Is it possible to do this without specifying types?
(VB.NET 2005 with .Net 2.0)
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Jan 25, 2010
how can i highlight my item after i added it to a listview that contains other items.
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Jan 17, 2011
I have a problem with adding items to generic list, problem is when I add 1. item to the list, everything is ok, but when I add second, first and second has the same values...
This is code (asp.net 4.0):
Partial Class _Default
Inherits System.Web.UI.Page
<Serializable()>
Public Class Product
Shared Property Material As String
[URL]
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Jun 22, 2010
The idea with this form is to add the futures which is calculated when the button is pushed but I need the list to update every time and show the values each time to which the previous value is added to the new calculation, e.g. of what it should look like in listbox:
Year 1: $1,290.93
Year 2: $2,724.32
Year 3: $4,350.76
etc....
I have been working on this a while and I am at a standstill, I was given a function to clear the form everytime it calculates but I don't know how to implement it, I am new to VB. Here is what I have so far:
Public Class frmFutureValue
Private Sub btnCalculate_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles btnCalculate.Click
[code]....
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Jun 2, 2011
Does anybody know how to pass a reference to the current item in a generic list, when processing that list? In VB.NET you have to use a delegate wrapper to pass parameters in a delegate, which I have set up OK, but I don't know how to get a reference to the current item that would be the parameter used at in the example below. Using the Current property of the list enumerator doesn't seem to work, but how else could this be done?
[Code]...
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Oct 13, 2010
I want to check if a refdes already been added to the generic list.And if so he must not be added..How do I do this I looked every where and can not fins a solution. [code]
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Sep 30, 2009
I've created a custom control that I insert into my window with the following code
Code:
<controls:ListExpander Text="Class Diagrams"></controls:ListExpander>
The control in question contains several subcontrols, among others, a list. How can create the setup, so I can specify items that should be added to the list?
Code:
<controls:ListExpander Text="Class Diagrams">
<SomeItem>data<SomeItem>
<SomeItem>data<SomeItem>
<SomeItem>data<SomeItem>
<SomeItem>data<SomeItem>
</controls:ListExpander>
In which case the SomeItem objects should be added to the list in the ListExpander:
Code:
<ListBox Name="lstItems" Background="LightGray">
<ListBox.Items>
// Items should go here
</ListBox.Items>
</ListBox>
I'm quite new to WPF, but I suppose it's something along the lines of creating a dependency collection on ListExpander that takes object of the type SomeItem? I simply want to be able to give the control a few arguments which it can translate into items in the listbox contained within the the control.
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Jun 11, 2010
I have two datagridviews in my app. They're related. When there is no record in the parent datagridview, I select the "New Row" and then press the Add Button in the child datagridview's bindingnavigator. Then I get that exception:
InvalidOperationException: Item cannot be added to a read-only or fixed-size list.
I know why this happens.When I add new record to child datagridview, parent datagridview's new row loses focus and then delete row. So this error occures.How do I prevent my program from this exception. Remember, it's only occures if there is no record in the parent datagridview.
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Jan 18, 2009
How can i change the order that the items are added into the listbox? This is the original order:
[Code]....
And so on... What i want to do, in other words, is for the newest added item to be at the top of the list.
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May 20, 2011
in what situation will an item in System.Collections.Generic.List not be removed successfully?url...The way they phrase it makes me think that it is possible that a Remove operation on an item found in the List(Of T) could actually fail.
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May 5, 2010
i want to search item A (from a list of X items) in list B but i want to get the item not found example Search ITEM A in LIST B if not found then return a print....if found continue with ITEM B..and so on.
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Aug 7, 2009
I added a few items in the combobox dropdown list at the form load event. [code] At the runtime I dont want to allow the user to write something in the combobox as a text.The user can only select an item from the dropdown list of the combobox.
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May 1, 2012
I am working on a project for a class, and am having trouble getting my program to automatically calculate the subtotal every time an item is added to the shopping cart list. I've tried sub procedures and functions, but I can't seem to get it to work.
[Code]...
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May 30, 2011
I have a List(Of MyObj), and I want to iterate through that list and compare each element to all other elements in the same list, excluding (if possible) the same element. I have a solution that works, but it's slow and uses double For loops. It may possibly have also summoned Cthulhu from his sleep. This below is a sanitized version of what I have:
Dim MyList As New List(Of MyObj)({Obj1, Obj2, Obj3, Obj4, Obj5, Obj6})
If MyList.Count > 0 Then
For i = 0 To (MyList.Count - 1) Step 1
[code]....
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Nov 15, 2011
I want to know how to test the 1st list box if it has items more than the other list box but by one item, here is what i have: If lstInvisibleTv. Items.Count > lstInvisiblePc.Items.Count Then it works good if the lstInvisibleTv list box is greater than the other list box by one but it also works if it is greater the other one by one or more which I do not want. I want it to work just by one.
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Aug 21, 2011
Ok what I have is a combo box with a set of default items but i want the user to be able add new items to the combo box's item list. i currently have a text box and a command button for the user to use to add new items to the list with this code attached
ComboBox1.Items.Add(TextBox1.Text)
when the program is closed the item is no longer in the combo box items list.
so what i would like to know is the correct code to make the additions to the combo box's items list permanent or at least until the user chooses to remove them.
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May 27, 2012
I have a program that will compare an array of grocery list items glist and an array of coupon item clist.When I compare the two and if there is a match somewhere in the array I want to have a picturebox visible.When there is no match, I want the picture box not to be visible. [code] The code seems to work great until I come to the else statement.When the code finds a match it displays the picture box and the msgbox without error, but as soon as the message box is cleared, even though i've input it as an ELSE statement, the picturebox goes false again.Does anyone have any idea of how I can "hold" the picturebox to stay visible while the match between the arrays exists?
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Jul 5, 2010
In my application I have a listbox and SelectionMode should be MultiSimple because users need to see which items they selected. In another tab we have another listbox this one should show all the selection users had done in first tab. Private Sub
[Code]....
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Mar 14, 2011
I have a program that displays all of prisoners details.I use a form to add all of the details and then on another form it shows them, i have a search so that when you type the prisoner number in it will find that specific prisoner.When i add a prisoner a count in a textbox moves up 1 to show how many prisoners in the system.When i have added all of the prisoners i need to be able to go through them using a next and previous button.Can someone help me with the coding for these two buttons?
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Dec 6, 2011
how to write a program for a list box having 10 items in that just by a single click on one of the item it should be written on the button if a list is containing notepad than by clicking on the button it should open the notepad?
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Apr 5, 2011
I have a class called solution. This class has a property named cost. I also have a class called solutionList that inherits List(Of Solution). I have an instance of the solutionList class in another class called solutionGroup. Within the solutionGroup class I have a property called totalCost that sums the solution.cost property for all solutions in the solutionList.
But, I need a way to know when the cost has changed so that I can recalculate the solutionGroup.totalCost. I've added events to the methods that add or remove solutions from the list but I need a way to know if someone does something like
SolutionList.Item(0).cost = 100.
How to raise an event when the cost property of a solution that is in the solutionList is changed but with no luck.
Here is my solutionList class:
Public Class solutionList
Inherits List(Of Solution)
Friend Event listChanged(ByVal sender As Object, ByVal e As EventArgs)
Public Sub New()
End Sub
[Code] .....
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Feb 15, 2012
i i have a listbox and 1 button in my application thing i want is when i click on some listbox item auto press that button or when i click on some item in list box it remove selected items from list box just with mouse click
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Jul 26, 2010
I want to rearrange a list of items in different orders for few times; ie: the 2nd in the list becomes the 1st & the previous 3rd becomes the 2nd, ... then the Last one becomes the penultimate one.In the next round, the 3rd of the original list becomes the 1st & the 4th of the original becomes the 2nd and so on. (That is, each item moves one rank above & the Top one goes to the Bottom)Given below is an example.Here, I took only 6 items & rearranged for 5 times only. (I should be able to use several Items and to rearrange for many times).The Original List:
(1) Alpha, (2) Beta, (3) Gamma, (4) Delta, (5) Epsilon, (6) Zeta
2nd List:
(1) Beta, (2) Gamma, (3) Delta, (4) Epsilon, (5) Zeta, (6) Alpha
[code].....
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Jun 30, 2011
I am trying to create a list of a generic type in vb.net 2.0 framework.
This is the generic type definition:
Public Class GenericParamMap(Of T)
Public Sub New(ByVal pParamName As String, ByVal pPropValue As T)
mParamName = pParamName
[Code]....
The compiler does not allow a "T" in the method's parameter because it's not defined, but I'm not sure how or where to define it. I thought it was okay to have a generic method definition.
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Apr 20, 2010
Function runs fine on the listbox until i use the btnUp_Lanemgr click event
throws an exception in function (below in bold) "Unable to cast object of type system.string to type namespace.myitem"
what i can do to make this work?
'Button moves selected listbox item up
Private Sub btnUp_Lanemgr_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnUp_Lanemgr.Click
[Code]....
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May 1, 2012
CODE:
Is there anything I need to change about this code to let me insert list items to a listbox on the UI thread?
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