Getting Events To Bubble Up In Nested Objects
Oct 16, 2010If you have a class that is a combination of other classes how are you to get the events to bubble up to the parent class?
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Events In Nested Objects?
Oct 17, 2010I can't seem to find a lot on how to use events in nested objects. I suspect that I should have access to the events in the nested objects through intellisense if I had done things right. I have many objects with 50 or so properties and I would like to access them with out adding handlers for each one and additional events in parent objects.
Example:
Public Class Form1
Dim WithEvents myCombinedClass As New CombinedClass
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Bind Objects With Nested Objects?
Jul 21, 2009I am tring to bind a class to a form where the class contains other class variables. For example:
Class Character
Private _name as String
Property Name as String
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Array Of Child Objects In Nested Classes And Accessing Child Objects In .Net
Jan 3, 2012I have a nested class, let's call it class1 and it has class2 inside it; VB.Net eg:[code]
1) How can I define X number of Class2 objects[let's call it: Node(x) array]** with NEW() subroutine called?' this raises error: dim cls2(n) as new class2 end sub.
2) How can I return actual number of Node() array? [code]Outside my class in main project I define cls1 object:[code]Now an array of class2 is created inside cls1.
3) Now,How can I access All of them[node(x) array which is created inside cls1] with all properties and methods available?
I remember I wrote a ProcessManager class with this functionality in .net 2003, nearly 4 years age, I don't have the code now.
Child Objects Raising Events In Parent Objects?
May 1, 2009long story short, I have created a ListView type control, using UserControls for the parent control and the ListViewItems. Most the of the control is written and works fine, right up to the point where I tried to replicate the 'Control.SelectedItems(0).Index' property and the 'SelectedIndexChanged' event.
Each child object knows its index value, and could pass this value via the SelectedIndexChanged event (assuming this is how it works in a normal ListView control -- user clicks on an item, and that item fires an event updating the selected index value in the parent object).
How does the child object raise an event in the parent object? I have a feeling this could be done with Delegates, but I'm still learning about their usage.
.net - Nullable Nested Objects And The Maybe Monad?
Sep 19, 2011I'm struggling to implement a maybe monad - which I've called Nullable in this example.
The Nullable Class is implemented as follows: Public NotInheritable Class Nullable(Of TClass)
Private _value As TClass
Private _hasValue As Boolean
Public Shared Function Create(ByVal value As TClass) As Nullable(Of TClass)
Return New Nullable(Of TClass)(value)
End Function
[Code]...
The way the monad is implemented at the moment I would need to issue the following to access a property on the nested child class dim id = MyParentClass.ChildClass.Value.ID
but ideally what I'd like to be able to do is to have the following statement dim id = MyParentClass.ChildClass.Id and if the ChildClass is null then just return a default value for the property type.
I tried implementing this using Default Properties and setting the Value as default via an attribute but it wouldn't compile. Is that going to be possible or perhaps there is a better way of architecting it - or maybe I just haven't 'got' the maybe monad?
Bind/update Two ListBoxes To Nested Objects?
Apr 21, 2010I have two nested objects, and the form has two ListBoxes, where I want the last to respond to the selection of the former. It can even be some times deeper than 2 levels, which can make it a bit cumbersome. I solve it by raising events in any method that makes an add/delete/rename of these objects, and the form listens for these events, and when fired, clears it's lists, and loops through these objects to populate the lists again. binding lists, but this seems to introduce a few issues. First I need to keep a set of extra lists in the main BLL class, but more importantly, I feel I'm violating the layered structure between the BLL and the form, as in this case, the BLL needs to keep track of the current selected indexes of the listboxes in some variable. So that doesn't feel right, as it makes the BLL vulnerable to what the form does, and I assume is simply principally incorrect.
Following is example of object structure, where two ListBoxes should display "Company Names" and "Employee Names", and the Employee name listbox obviously change according to the selection in the Company Name listbox.
Public Class Form1
private _main as New Main
...
End Class
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.net - Handle Null Nested Objects In RDLC Report That Is Bound To Custom Assembly Object Datasource?
Aug 27, 2009I have an RDLC report that I am rendering directly to the Response Stream as PDF (rather than using the ReportViewer). In the code that renders the report, it's DataSource is bound to a List(Of ClassA) objects defined in a custom assembly. This seems to work for the most part. My problem is that I can't seem to handle the situation where a nested object is null. For example, given ClassA and ClassB (the nested object) defined as follows:
Public Class ClassA
Public Id As Integer
Public Name As String
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the report displays "#Error" if TheNestedObject is null. If TheNestedObject is not null, it correctly displays the Name.
.net Creating Objects In An Array With Events
Jul 25, 2011I'm having a problem at the moment developing my application. What i need to do is find out how many modems they are connected to my system and send data to each one in turn. I have the programme working for one modem at the moment.
So I can send data to a modem that i specify, for example a modem on COM port 1. I have functions already that will give me a list of COM ports that I need to open.My problem is that i want to dynamically create a new modem object along side existing modems and store them in a collection.
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Catch Events On Runtime Objects?
Mar 5, 2009I'm creating a form with a few buttons and a combobox at runtime.dim f as new form
(blah blah)
then the buttons acceptDescription and rejectDescription are set up...
then the combobox descriptionCombo is set up...
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Catching Events In ArrayList Of Objects
Jul 22, 2009I have an ArrayList that is populated with Objects. These Objects raise events at certain times. How can I capture these events from the ArrayList? i.e.
I want something like this:
Public Sub MyRaisedEvent(ByVal obj as MyObject) Handles MyArrayList.MyEvent
End Sub
IDE :: Handle The Events For This Type Of Objects?
Jan 15, 2009I created a Class which inherits Combobox and the listview is added . Now what I need is once the user click listview, the listview has to close and the clicked item has to added with combobox text. simply can say combobox1.text = listview.item(0).textFor closing & displaying the listview I need to handle the events. For
My Codings :========Public Class Combu_lstviewInherits ComboBoxPrivate treeViewHost As ToolStripControlHostPrivate Shadows dropdown As ToolStripDropDownPublic mylistview As New ListView
Public Sub New()mylistview.BorderStyle = BorderStyle.Nonemylistview.View = View.Detailsmylistview.HeaderStyle =
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List Of Objects And Shared Events
Dec 8, 2010Okay so I've created a list of objects from a class like
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.net - Handling Events For Late-bound Objects?
May 7, 2009I would like to use MS Office automation and have event handlers that fire for user-triggered events. For example, if the user clicks the save button in Word, I want to intercept that event and execute code in my program.
I don't want to be bound to a specific version of Word because I don't know what version my user will be running, so I instantiate a reference to Word using late binding. The problem is that the AddHandler and the Dim WithEvents commands require specific references to an object that is known at design time. Given this, how can I define an event handler without having an early bound reference to a specific version of the Word library?
I can try to a reference to an earlier version of Word with the expectation that newer versions of Word will be backwards compatible, but this seems kludgey and risky.
Bind Events Dynamically To Objects Within A List<of T>?
Dec 9, 2010I have a List<of T> with certain objects. Every individual object has 3 events. How can I bind those events dynamically to methods?.
View 3 RepliesHandle Events For Objects NOT Created In The Design Tab?
Jan 10, 2012I have created a PictureBox array to hold 104 playing cards that are all visible at the same time.I did this with this line in the declarations:Shared Card(104) As PictureBox
And with these lines in the Form_Load module:
For I% = 1 To 104
Card(I%) = New PictureBox
Card(I%).Name = String.Format("Card{0}", I%.ToString)
Card(I%).Size = New Size(71, 96)
[Code]...
I have been successful in creating the array, positioning each and entering the images for all 104 PictureBoxes, but now I want to add code for the event "MouseDown.I copied the code for this event from my VB3 program and VB10 automatically updated the list of parameters, but nothing has linked the objects (Card) to the code.
I have tried to append "Handles Card.MouseDown" as well as several variations with brackets to indicate that it is an array.Auto-complete doesn't include "Card" as an option, and of course, since the array was never an object added to the form design, I can't create the empty module from there.
Referencing Dynamic Objects To Create Events?
Nov 20, 2010I have a tools strip menu item with dropdown items that are created dynamically.
For Each file In files
Dim newMenu As New ToolStripMenuItem(FileNameOnly(file))
tsmMachType.DropDownItems.Add(newMenu)
Next
So how would I go about setting up or creating events for these items? I need to have a check event and click event for each of the items.
Object Handle Events Fired In Other Objects Without A Special Sub?
Jul 28, 2010I've been thinking about my options when it comes to events in vb.net.What I'd like to do is to track events that are fired in an application without explicitly declaring them with 'handles' sub. Here is a pseudo-[code]....
Yeah I know, not quite working, but is there any way of implementing something like this in vb.net? My end game is really to be able to monitor events fired in many objects from another object, isn't there a more maintainable way to do that then to add a special sub in each object that handles the event that I want to catch? I need some way to let one object handle events fired in other objects without a special sub, the AddHandler goes a long way, but I can't really use that dynamically like so:[code]....
Forms :: Handling Events From WebBrowser Objects Contained In An ArrayList?
Jul 18, 2009I'm writing a tabbed web browser for someone who is learning VB.NET, and I have got to the point where I can add/remove browser controls into tab pages, controlled by one set of buttons on the main form, but I can't handle events from the WebBrowser objects.I have tried this but it says that 'DocumentTitleChanged' isnt an event of 'Control'...
Dim browser As New ArrayList
browser.Add(New WebBrowser)
browser(0).parent = TabControl1.SelectedTab
browser(0).dock = DockStyle.Fill
AddHandler browser(0).DocumentTitleChanged, TitleChangedHandler()
I want to update the tab title with the web page title when it changes. I started using a timer to update the tabs but there must be a way to add an event handler here.
Office Automation :: Triggering Events On Excel Objects (ex: Buttons)
May 5, 2010I am using vb .net and office 2007 with Microsoft.Office.Interop.Excel.Application loaded in a vb net project.I have this excel file filled with buttons and drop down objects... i need to change the value of the drop downs and then click a button, all this inside vb .net.I have my workbooks, sheets and ranges all setup, i just need a headstart to, for example, change a drop down value, to say... item number 2.
View 1 RepliesVS2010 IDE - Lost The Small Window Which Displays The Objects And Events Of The Current Tab
Apr 10, 2011I have lost the small window which displays the objects and events of the current tab. How can I get that back?
This is a screenshot. I have lost the highlighted area!
Two Objects That Are Raising Some Events - Pressing A Button - Raise A Custom Event, Then Execute A Method And Then Close The Form
Mar 30, 2011Problem that you may have when dealing with two objects that are raising some events. Here, to make it obvious, I am closing the form, but the problem can be experienced with any other 2 classes event. First, what is the problem !
Let suppose that by pressing a button, you want to raise a custom event, then execute a method and then close the form
In that case, you may use a code similar to this
Event BeepIt()
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
RaiseEvent BeepIt()
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Loop And Enumerate Properties Of Nested Classes In Nested Classes?
Sep 24, 2010so far i got
code
For Each item As Reflection.FieldInfo In GetType(NameSpace.ClassWithNestedClasses).GetFields
rtfAppend(item.Name & ":" & Tab & item.GetValue(Me))
Next
For Each item As Reflection.PropertyInfo In GetType(NameSpace.ClassWithNestedClasses).GetProperties()
[code]...
which gets me the simple string vars and properties of my top class, but how can i apply this to loop through all sub classes and get there vars and props?
Bubble Sorting An Array?
Jun 3, 2011I'm trying to bubble sort an array then display it in a list box. When I click the button the program crashes.
Here is my code:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If Not TextBox1.Text = "" Then
ListBox1.Items.Add(TextBox1.Text)
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And the compiler gives me this error: A first chance exception of type 'System.IndexOutOfRangeException' occurred in WindowsApplication1.exe
How To Bubble Sorting With Numbers
May 5, 2011how do i do bubble sorting with numbers?
View 1 RepliesVS 2008 - Checkbox In A Bubble?
Jan 7, 2010Is it possible to have a checkbox in a bubble, so that when it show up in the tray you can check the box, i.e. "Don't Show this Again"
View 5 RepliesBubble Object Collision And Separation
Apr 26, 2012I am working on a program that has bubbles being generated at the bottom of a panel and rising to the top I have all of that worked out but am having trouble figuring out how to detect when a bubble collides with another bubble and then seperating these two bubbles.[code]
View 1 RepliesBubble Sort Ascending Order?
Feb 22, 2011ListBox2.Items.Clear()
Dim list() As Integer
Dim count As Integer = ListBox1.Items.Count
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Bubble Sorting Words Alphabetically?
Jan 15, 2012i have a few names in a list box (string). How do i use bubble sorting to sort them in alphabetical order.
View 3 RepliesVS 2008 How To Bubble Sort Datagrid
Mar 27, 2012Dim cn As String = ("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=Database genk.mdb;")
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I am trying to use bubble sort to sort to sort the deatils shown on the datagrid. The buuble sort code is there and the data grid view code is there which retrives the product details in my databse. How would i link the two together so that when the user clicks the button it uses the bubble sort code to sort and view the product deatils in order of the selected coulmn name selected by the user through a combo box?