VB.Net, Listbox.Remove method

Listbox.Remove method

Author	Message
Jim Heave #1 / 6	Listbox.Remove method I created a number of objects and added those objects to a list box. Now when I attempt to use the remove method, it seems to function, but when the form is displayed back, the item is not removed, What gives? Is there something more that I need to do to get it out of the listbox? Your assistance is greatly appreciated!
Sun, 17 Apr 2005 04:28:11 GMT

VBDotNet Team [MS #2 / 6	Listbox.Remove method It sounds like you may be using the properties window to define the listbox entries and then using code to remove an item. If that is the case, when you create a new instance of the form it will grab all the values from your design-time settings in the property grid. You will need to remove the values from the property grid in design-mode. Dave & Jim VB .NET Development -- This posting is provided "AS IS" with no warranties, and confers no rights. Quote: > I created a number of objects and added those objects to a list box. Now > when I attempt to use the remove method, it seems to function, but when the > form is displayed back, the item is not removed, What gives? Is there > something more that I need to do to get it out of the listbox? > Your assistance is greatly appreciated!
Sun, 17 Apr 2005 05:46:52 GMT

Jim Heave #3 / 6	Listbox.Remove method I am adding the entries to the listbox via code and I am removing them by code. The code to add the entries is as follows (pulling the entries from the DataSet - building my object - and then adding the object to the Listbox: Do Until i = DsStockData2.Tables("Company").Rows.Count() Dim obj As StockData Dim exch As Integer If DsStockData2.Tables("Company").Rows(i).Item("Exchange") Is DBNull.Value Then exch = 0 Else exch = DsStockData2.Tables("Company").Rows(i).Item("Exchange") End If obj = New StockData(DsStockData2.Tables("Company").Rows(i).Item("Comp_ID"), _ DsStockData2.Tables("Company").Rows(i).Item("Name"), _ DsStockData2.Tables("Company").Rows(i).Item("Symbol"), _ exch, _ DsStockData2.Tables("Company").Rows(i).Item("TotalHeld")) lstCompanyNames.Items.Add(obj) i += 1 Loop Here is the code to remove the item from the listbox.... MsgBox("Total items before the delete of item in listbox = " & lstCompanyNames.Items.Count) lstCompanyNames.Items.Remove(lstCompanyNames.SelectedIndex) MsgBox("Total items now in the listbox = " & lstCompanyNames.Items.Count) The row count before the delete is 12 and the rowcount after the delete is 12. Quote: > It sounds like you may be using the properties window to define the listbox > entries and then using code to remove an item. If that is the case, when > you create a new instance of the form it will grab all the values from your > design-time settings in the property grid. You will need to remove the > values from the property grid in design-mode. > Dave & Jim > VB .NET Development > -- > This posting is provided "AS IS" with no warranties, and confers no rights. > > I created a number of objects and added those objects to a list box. Now > > when I attempt to use the remove method, it seems to function, but when > the > > form is displayed back, the item is not removed, What gives? Is there > > something more that I need to do to get it out of the listbox? > > Your assistance is greatly appreciated!
Sun, 17 Apr 2005 08:50:25 GMT

JimM #4 / 6	Listbox.Remove method I wouldn't swear that this is your solution, but are you using an underlying datatable as the source for the listbox, you'd have to delete the record from the underlying datatable and perform and update before the item would be omitted. I may be reading this too simplistically tho... --- Jim --- Quote: > I am adding the entries to the listbox via code and I am removing them by > code. The code to add the entries is as follows (pulling the entries from > the DataSet - building my object - and then adding the object to the > Listbox: > Do Until i = DsStockData2.Tables("Company").Rows.Count() > Dim obj As StockData > Dim exch As Integer > If DsStockData2.Tables("Company").Rows(i).Item("Exchange") Is > DBNull.Value Then > exch = 0 > Else > exch = DsStockData2.Tables("Company").Rows(i).Item("Exchange") > End If > obj = New > StockData(DsStockData2.Tables("Company").Rows(i).Item("Comp_ID"), _ > DsStockData2.Tables("Company").Rows(i).Item("Name"), _ DsStockData2.Tables("Company").Rows(i).Item("Symbol"), - Hide quoted text - - Show quoted text - Quote: > _ > exch, _ > DsStockData2.Tables("Company").Rows(i).Item("TotalHeld")) > lstCompanyNames.Items.Add(obj) > i += 1 > Loop > Here is the code to remove the item from the listbox.... > MsgBox("Total items before the delete of item in listbox = " & > lstCompanyNames.Items.Count) > lstCompanyNames.Items.Remove(lstCompanyNames.SelectedIndex) > MsgBox("Total items now in the listbox = " & lstCompanyNames.Items.Count) > The row count before the delete is 12 and the rowcount after the delete is > 12. > > It sounds like you may be using the properties window to define the > listbox > > entries and then using code to remove an item. If that is the case, when > > you create a new instance of the form it will grab all the values from > your > > design-time settings in the property grid. You will need to remove the > > values from the property grid in design-mode. > > Dave & Jim > > VB .NET Development > > -- > > This posting is provided "AS IS" with no warranties, and confers no > rights. > > > I created a number of objects and added those objects to a list box. > Now > > > when I attempt to use the remove method, it seems to function, but when > > the > > > form is displayed back, the item is not removed, What gives? Is there > > > something more that I need to do to get it out of the listbox? > > > Your assistance is greatly appreciated!
Sun, 17 Apr 2005 23:52:41 GMT

Jim Heave #5 / 6	Listbox.Remove method I do have a data table which provides the information that I am using to build my objects, but then after that, there is no relationship between my data tables and the list box. If I had bound my datatable to the list box control, then, as you have suggested, the problem would be in deleting the row from the datatable and then that supposidly would have made the list box correct.....but this is not the situation! Still lost to explain why the row still remains.... Quote: > I wouldn't swear that this is your solution, but are you using an underlying > datatable as the source for the listbox, you'd have to delete the record > from the underlying datatable and perform and update before the item would > be omitted. I may be reading this too simplistically tho... > --- Jim --- > > I am adding the entries to the listbox via code and I am removing them by > > code. The code to add the entries is as follows (pulling the entries > from > > the DataSet - building my object - and then adding the object to the > > Listbox: > > Do Until i = DsStockData2.Tables("Company").Rows.Count() > > Dim obj As StockData > > Dim exch As Integer > > If DsStockData2.Tables("Company").Rows(i).Item("Exchange") Is > > DBNull.Value Then > > exch = 0 > > Else > > exch = DsStockData2.Tables("Company").Rows(i).Item("Exchange") > > End If > > obj = New > > StockData(DsStockData2.Tables("Company").Rows(i).Item("Comp_ID"), _ DsStockData2.Tables("Company").Rows(i).Item("Name"), - Hide quoted text - - Show quoted text - Quote: > _ > DsStockData2.Tables("Company").Rows(i).Item("Symbol"), > > _ > > exch, _ > > DsStockData2.Tables("Company").Rows(i).Item("TotalHeld")) > > lstCompanyNames.Items.Add(obj) > > i += 1 > > Loop > > Here is the code to remove the item from the listbox.... > > MsgBox("Total items before the delete of item in listbox = " & > > lstCompanyNames.Items.Count) > > lstCompanyNames.Items.Remove(lstCompanyNames.SelectedIndex) > > MsgBox("Total items now in the listbox = " & lstCompanyNames.Items.Count) - Hide quoted text - - Show quoted text - Quote: > > The row count before the delete is 12 and the rowcount after the delete is > > 12. > > > It sounds like you may be using the properties window to define the > > listbox > > > entries and then using code to remove an item. If that is the case, > when > > > you create a new instance of the form it will grab all the values from > > your > > > design-time settings in the property grid. You will need to remove the > > > values from the property grid in design-mode. > > > Dave & Jim > > > VB .NET Development > > > -- > > > This posting is provided "AS IS" with no warranties, and confers no > > rights. > > > > I created a number of objects and added those objects to a list box. > > Now > > > > when I attempt to use the remove method, it seems to function, but > when > > > the > > > > form is displayed back, the item is not removed, What gives? Is > there > > > > something more that I need to do to get it out of the listbox? > > > > Your assistance is greatly appreciated!
Mon, 18 Apr 2005 05:12:11 GMT

Jim Heave #6 / 6	Listbox.Remove method OK, I figured it out. The "Remove" method apparently wants the value to be removed and not the index which contains the value to be removed. I would have thought that the method would a failed or something along those lines if you attempted to remove something which was not there, but that apparently is not the case. The RemoveAt version provides for you to delete a specified item based upon the index. I will use this method. So I found my error. Thanks for everyone's assistance. Quote: > I do have a data table which provides the information that I am using to > build my objects, but then after that, there is no relationship between my > data tables and the list box. If I had bound my datatable to the list box > control, then, as you have suggested, the problem would be in deleting the > row from the datatable and then that supposidly would have made the list box > correct.....but this is not the situation! > Still lost to explain why the row still remains.... > > I wouldn't swear that this is your solution, but are you using an > underlying > > datatable as the source for the listbox, you'd have to delete the record > > from the underlying datatable and perform and update before the item would > > be omitted. I may be reading this too simplistically tho... > > --- Jim --- > > > I am adding the entries to the listbox via code and I am removing them > by > > > code. The code to add the entries is as follows (pulling the entries > > from > > > the DataSet - building my object - and then adding the object to the > > > Listbox: > > > Do Until i = DsStockData2.Tables("Company").Rows.Count() > > > Dim obj As StockData > > > Dim exch As Integer > > > If DsStockData2.Tables("Company").Rows(i).Item("Exchange") Is > > > DBNull.Value Then > > > exch = 0 > > > Else > > > exch = DsStockData2.Tables("Company").Rows(i).Item("Exchange") > > > End If > > > obj = New > > > StockData(DsStockData2.Tables("Company").Rows(i).Item("Comp_ID"), _ > DsStockData2.Tables("Company").Rows(i).Item("Name"), > > _ > > DsStockData2.Tables("Company").Rows(i).Item("Symbol"), > > > _ > > > exch, _ > > > DsStockData2.Tables("Company").Rows(i).Item("TotalHeld")) > > > lstCompanyNames.Items.Add(obj) > > > i += 1 > > > Loop > > > Here is the code to remove the item from the listbox.... > > > MsgBox("Total items before the delete of item in listbox = " & > > > lstCompanyNames.Items.Count) > > > lstCompanyNames.Items.Remove(lstCompanyNames.SelectedIndex) > > > MsgBox("Total items now in the listbox = " & > lstCompanyNames.Items.Count) > > > The row count before the delete is 12 and the rowcount after the delete > is > > > 12. > > > > It sounds like you may be using the properties window to define the > > > listbox > > > > entries and then using code to remove an item. If that is the case, > > when > > > > you create a new instance of the form it will grab all the values from > > > your > > > > design-time settings in the property grid. You will need to remove > the > > > > values from the property grid in design-mode. > > > > Dave & Jim > > > > VB .NET Development > > > > -- > > > > This posting is provided "AS IS" with no warranties, and confers no > > > rights. > > > > > I created a number of objects and added those objects to a list box. > > > Now > > > > > when I attempt to use the remove method, it seems to function, but > > when > > > > the > > > > > form is displayed back, the item is not removed, What gives? Is > > there > > > > > something more that I need to do to get it out of the listbox? > > > > > Your assistance is greatly appreciated!
Mon, 18 Apr 2005 13:16:11 GMT

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