VS 2005 - Controlcollection - Make A Collection Of Controls That I Can Loop Through
Mar 2, 2010
I am trying to make a collection of controls that I can loop through. So I have this code in my form... Dim WizardFrameCollection As New Control.ControlCollection(Nothing)
I then try to add controls to the collection by I get a error "Object reference not set to an instance of an object." WizardFrameCollection.Add(Me.GroupBox1) I am not sure why I am getting this error. Groupbox1 is a groupbox that is on the form.
I have a Collection, the keys are strings and the values are Collections. In the sub Collections the keys are strings and values are Singles/Floats. How would I loop through all of the data? I need to get the keys and values not just the values. I've tried this but it produces a cast error:
I often use a for/next loop to cycle through a collection to find a particular member of that collection based on some criteria. This works fine in every case except one: when I want to then erase the very member of the collection I just found. For example, if I wanted to give the heave-ho to every obect in a collection class that has a member veriable Color equal to Red:
[Code]...
The problem is once the collection class member is erased it makes to loop invalid because taking out the member reduces the total count of the collection in the middle of the loop. Eventually I get a "Index is out of range" error.This circumstance has bothered me every so often; I bet more experienced programmers have a different type of loop system that works better than this when you want to erase a collection member.
I have a BackgroundWorker and the DoWork event, calls a function called "JustMe", it executes a loop to make visible all the controls on a panel, but does not work vb.net
Private Function JustMe As Boolean For Each ctr As Control In Panel1.Controls ctr.Visible = True Next Return True End Function Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork JustMe() End Sub
I have an ASP.NET app with lots of textboxes all over the page that need updating at various points through program execution. These textboxes actually belong to a certain class, so for easy updating I thought I could create a Dictionary(Of string, object) and add the control.ID and the control to it and then for updating do something like this:
I define a new instance of a forms control collection, but at runtime, the collection is empty. It works for one load button on the form, but not another. The code is exactly the same, but one works, the other doesn't. Here is the relevant code:
Private Sub miFLoad_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles miFLoad.Click Dim FilePath As String = "C:FListFList.flt"
I have been researching for a couple of days now and to no avail. Does Anyone know how to make a custom collection that take advantage of the collection editor? I would like to be able to have 3 Color Values, 1 Boolean and 1 String.
I have aspx form with several textboxes.They are populated with values from a table via retrieval of a dataview.If the row count for the dataview is 0, then I'd like to reset the values in all textboxes. How can I loop through all the textboxes and set a default value?I've tried the following, but no sucess.
For Each ctrl As Control In Page.Form.Controls If TypeOf ctrl Is WebControls.TextBox Then CType(ctrl, WebControls.TextBox).Text = "" End If Next
My first For Loop was using Page.Controls but it returned only 1 count.The textboxes are inside a tabpanel (ajax), so do I have to locate the tabpage and then find all it's controls (for each tabpage)?
I am rather irritated at this. I have no clue why looping through controls on a form and in groupboxes leaves out 75% of the controls.
Here's the code I have:
Dim settings As String = "" Dim gbControl As Control Dim gbbox As Control
[Code]....
I want to have setting save all settings to an ini file, and not have to reprogram the saving routine when I add a group box or control. At random times, any number of controls can be disabled, checkboxes can be checked and unchecked, radiobuttons can be checked and unchecked. Regardless of the state of the control, I want the control to show up in the loop. But they don't. Only controls that are enabled and only checkboxes that are checked, every other control state is ignored. That's crap, and is definitely not what is needed by any programmer of any type. We're capable of determining if a control is enabled, hidden, checked, visible, and otherwise.
How do I get the controls to be included in the loop regardless of their state?
I have a simple Dictionary(of String, Object) that I need to iterate through and change items depending on some conditions.As I can't modify a collection that I'm iterating through, how do I achieve this?For example, the following obviously causes an Invalid Operation Exception:
Dim mOptions As New Dictionary(of String, Object) mOptions.Add("optA", "A") mOptions.Add("optB", "B") mOptions.Add("optC", "C")
In an application I am working on I have created a product class which represents an inventory item. I have also created an inventory class which represents a collection of product objects. In the constructor of the Inventory class I load 4 products into a product collection. Each product consists of a code, description price and quantity.
I'm trying to just iterate through this xml and grab all of its data and add it to my collection(_personOC). Right now it's not working. How can I do this without having to specify the id? All I did was make a dataset with a person table and saved it as a xml.
Public Property personOC As ObservableCollection(Of Person) Get Return _personOC
I decided to go back to the VB6 book, "Learn to Program Visual Basic Objects", so I can code it in VB2010. This has been a great learning experience. However I've run into a problem. I'm getting an error with a For....Each loop for a collection class. The error message states, Expression is of type 'China.Order', which is not a collection type." From what I've deduced the problem deals with an enumerator. I could be wrong.
I'm trying to loop through a collection object in vb2010.The code was originally used in Vb6 The book said that I needed to code a NewEnumerator method first in order to be able to loop through my collection. I coded the following:
[code]...
It gives an error for IUnknown, staging that IUnknown is not accessible in this context because it is a 'Friend'.In the line in the function I removed the Set since it's no longer needed.The error message for this line is '_NewEnum' is not a member of 'Microsoft.VisualBasic.Collection'What are these messages and how do I fix this in VB 2010?m_colCourse is not a system collection.
I want to display a list of open windows on my computer in a rich text box. So, I'm trying to store the names of all windows in myString, and then set RichTextBox1.Text = myString.
Here's the code
Imports System Imports System.Collections.Generic Imports System.Collections.ObjectModel
I'm a bit confused here. I'm copying all the controls from one form to a panel on the main form and for some reason only about half of them copy.
Private Sub switchComponent() Dim selection As String = TreeView1.SelectedNode.Text Panel1.Controls.Clear()[code]....
When stepping through the code, serverDic(selection).Controls has 12 elements, but only 6 of them get copied. Next time this gets called, only 3 get copied. Does Panel1.Controls.clear() somehow kill the references?
EDIT: Just to show that there are infact 12 elements in the collection:
I often see code snippets for handling each control of a certain type on a form or panel, etc.They always start with For Each ctrl and the do a test for control type.Many .NET users are not aware, as I was not until I tried it recently, that we can LINQ on the controls collection.Below is a simple sub I created for resetting every checkbox on a panel I use as a validator.
Private Sub ResetCheckBoxes(ByRef pnl As Panel) Dim ctrls as System.Collections.Generic.IEnumerable(Of Object) ctrls = From c In pnl.Controls Where TypeOf (c) Is CheckBox
I am trying to use a Web Service to return Json for a Collection of Users from a Database Table. I'm only new to .NET (< 1 week experience), and I don't want to use the UpdatePanel for AJAX. I have tried using the JavaScriptSerializer as well as Json.NET to serialize. Both cases seem to spawn an Infinite Loop.[code]
Is there a way to to combine line's 1 and 2? I only want to loop through a list of the selected items in this listbox. This works just fine, I just wondered if there was a collection of selected values returned that I could use to avoid having to do it this way.
For Loop1 = 0 To MyListBox.Items.Count - 1 If MyListBox.Items(Loop1).Selected = True Then ... End Next
I am constructing a program, i am new to Visual Basic, but i have past programming experience. I was wondering if anyone knew how to form a loop that could...lets say calculate the answer when two numbers are added together,and it would repeat this thousands of times, etc. And if there is a way, would it be possible to calculate the time taken to complete this loop.
Does anyone know how I can access the FontDialog's controls collection? I would like to disable the Font Style ListBox, set the Font Style's TextBox to readonly and disable the UnderLine and StrikeOut CheckBoxes.
Maybe if I knew the right termanology, I could find the answer myself.. I am going to run a fairly long list of "If"s that will determine if certain controls appear on the form or not. In it's simplest form would be:
I am writing a simple control translation function that reads an XML file containing control names and their localized text. Within the application, each time a form is loaded, it iterates through every control and tests to see if that control is defined in the XML file. If it is, it then sets the control text to whatever localized text is defined in the XML file.
There are some tests and additional requirements (i.e. nested loops) for TabControl and MenuStrip etc., but the control that is giving me the most trouble is the ContextMenuStrip.[code]...
This is weird. I have a class that inherits from IEnumrable whose Count property is reporting 0 (zero) elements but the For Each loop steps into the loop body and tries to use the variable where it should just be moving on. My code:
On Error Resume Next Dim d As Foo For Each d In fooCollection ' use d and throws an exception Next d
Weirder still, every time d is accessed i get an exception thrown in the output window:
A first chance exception of type 'System.NullReferenceException'
but i'm not stopping on the exception (not in a try/catch block).Is "On Error Resume Next" causing this weirdness?
Weirdness found:Per Rowland's and JohnH's comments i checked the Foo class:The GetEnumerator method inside of Foo didn't actually return anything! It had an empty body. That coupled with the On Error Resume Next before the loop caused the havoc! Wow this was ugly.
I would like to be able to save to a db and send task to email or as text msg for instance nevermind that.. I have two variables of type ArrayList they are "_mList1" , "_mList2" and "_mList3"
_mList1 stores the list of Telephonenumbers , _mList2 stores the list of StaffIDs and _mList3 Some concatenated string.
theses variable lists will hold some data in runtime as explained and i would like to use them to populate a DB table again mentioned
