Parent Property For A Non Visual Object?
Feb 21, 2010Is there a way for an object to call the object that contains it, like how a FrameworkElement has a Parent Property?Bill Gates look out!
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Cannot Cast An Object To Its Parent Object In Visual Basic
Aug 19, 2011In C# we can do something like this:
Honda a = new Car(); and that works but the same one doesn't work in Visual Basic.NET (I am fairly new to Visual Basic)
Dim a as Honda = new Car and it says Unable to cast object of type 'SampleApp.Car' to type 'SampleApp.Honda'.
Here is my sample code:
Module Module1
Sub Main()
Dim a As B = New A
[Code]....
Function - Pass Object Versus Reference Object In Parent?
Dec 1, 2011I am working on a application that has quite a few functions involved and have been thinking of the following: If I have a function that has a few paramaters, is it more efficient to pass the objects to the function(Example 1) or reference the objects in the parent(Example 2)? Does it matter if the objects are large or not?
Example:
Class mainform
Public myGenericList As New List(Of String)
Public myDatarowArray() As DataRow
[Code].....
Restrict Instantiation Of An Object To Only One Other (parent) Object?
Apr 27, 2010VB 2008 .NET 3.5 Suppose we have two classes, Order and OrderItem, that represent some type of online ordering system. OrderItem represents a single line item in an Order. One Order can contain multiple OrderItems, in the form of a List(of OrderItem).
Public Class Order
Public Property MyOrderItems() as List(of OrderItem)
End Property
End Class
It makes sense that an OrderItem should not exist without an Order. In other words, an OrderItem class should not be able to be instantiated on its own, it should be dependent on an Order class to contain it and instantiate it. However, the OrderItem should be public in scope so that it's properties are accessible to other objects. So, the requirements for OrderItem are:
[Code]...
Reflection - Find From A Property Info Object If That Property Has A Non Public (Private / Protected) Setter?
Aug 27, 2009I searched on the forum / Internet for the solution how a PropetryInfo object (of a Public property) can reveal if it has a Private Protected Setter ... it was all in vain .... all help I found was about how to "Set" value of a public property having a Private Setter.I would like to know if I have a PropertyInfo object of a public property, how would I know if its Setter is Non Public?
I tried, in a exception handling block, where I did a GetValue of the PropertyInfo object and then called SetValue by setting the same value back... but to my surprise it worked well and didn error out.
[Code]...
Databinding An Object Property And Modifying Another Property In Code?
Jan 15, 2010on a Windows Form, an object myObject is bound to myObjectDataBindingSource like this:myObjectDataBindingSource .DatSource = myObject on the form, i have a check box bound to the property: chkProp1 for example of the object: myObjectDataBindingSource In the code when the checkbox is clicked, I need to go in code and change another text property of the object txtProper2 for example like this:
Private Sub chkProp1_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles chkProp1.CheckedChanged
[code].....
Forms :: Set Property Of Parent Class From Child
May 14, 2009I would like to have a form class that is called from a button on a parent form and would like a button on the child form to set a property on the parent form. Can anyone explain the best way to go about this or direct me to a good article?
[Code]...
Compare An Object Property To Another Object Property?
Jul 4, 2011I have a listbox of a object called Account, which has 2 fields, password, and username. How can I compare a New Account to all the accounts in the list and see if the password matches?
View 3 RepliesHandle An Object's Object Property Changed Event In .NET Windows Forms?
Jun 7, 2012I know how to handle a single objects property changed event very easily. I want to handle a objects property changed event that is part of another object.
Given Object:
[ObjectY = Y]
+ Public WithEvents X As ObjectX
I would like to do something like:
Private Sub XPropertyChanged() Handles Y.X.PropertyChanged
Right now I need to create a object that equals the object inside that object and then handle this variable pointers property changed, but that is just annoying.
Assigning An Object Property Using A Variable As The Property Name?
Aug 4, 2009I want to assign an object property by referencing the property dynamically, with a variable name
i.e.
dim propName as string
staticObjectName.propName = 'whatever
Asp.net - Access Parent Page Property From User Control?
Nov 4, 2010Trying to access a property from the parent page on my user control.
Here's the start of my default.asp codebehind:
Partial Class _Default
Inherits System.Web.UI.Page
Private _selectedID As String = "74251BK3232"
[Code].....
I'm getting the error "selectedID is not a member of System.Web.UI.Page"
C# - From A UITypeEditor, Retrieve An Attribute Applied To The Parent Of A Property In .net?
Jan 20, 2010Consider this scenario:
Class MyClass
Property SubProp1
End Property
[code]....
Next, I put an instance of MyButton into a property grid, expand property MC and edit SubProp2.From the type editor for SubProp2, I want to get hold of the attribute applied to property MC.Looking at the context,PropertyDescriptor.ComponentType, we arrive at Type: MyClass.If i look at the attributes applied to MyClass, though, it will only return the attributes applied directly to MyClass, and not the extra attribute applied to the property MC.
VS 2008 Referencing A Property In The Parent ITEMS Class
May 6, 2010I have a collection class, say ITEMS, that inherits a Dictionary (of String, SINGLEITEM). From the SINGLEITEM class, I would like to reference a property in the parent ITEMS class, what is the best way to do this? For example, say the ITEMS class has an IsDirty property and I would like to set that if ANY of the contained SINGLEITEM objects is modified, what's the best way to go about doing this?
I know I could add a reference to the collection class in each SINGLEITEM class (since I override the ADD method, I could make this assignment), but this seems like overkill.
.net - Object Reference Not Set To An Instance Of An Object: Child Property?
Nov 21, 2011I'm checking If a border's child property is not set to nothing or equal to a given element, but whenever I run the program, it says that it's set to nothing and crashes. Here's my code:
If Not Me.Child.Equals(Nothing) Then ...
If Me.Child.Equals(value) Then ...
Both gives an error. What should I do to pass these lines? Also in C# it would look like this:
if(this.Child != null) ...
if (this.Child != value) ...
But this time it doesn't give an error.
Visual Basic Error Object Reference Not Set To An Instance Of An Object?
Sep 25, 2011I have this visual basic error and i was wondering if anyone could help.Private Sub SearchToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SearchToolStripMenuItem.Click
[Code]...
Check All Items Under A Parent Node In Visual Basic?
Jun 25, 2010I am trying to check all the childnodes under a parent node, the code I have so far only goes about 2-3 levels deep in the TreeView and I am looking to grab all nodes no matter how deep they are.
Below is the code:
Private Sub CheckChildNode(ByVal currNode As TreeNode)
'set the children check status to the same as the current node
Dim checkStatus As Boolean = currNode.Checked
For Each node As TreeNode In currNode.Nodes
[code]....
Calling A Sub And Pass In Parent Object?
Jul 6, 2009I have a statement that will call a Sub.
Charts(CurChartNo) = Server.CreateObject("ChartFX.WebServer")
Call InitChart()
Inside this sub, I will assign values to the properties of the Charts object that is
Public Sub InitChart()
Charts(CurChartNo).RGB2Dbk = &HC0FFFF&
Charts(CurChartNo).Chart3D = False
[code]....
But the Charts is not recognized in the Sub. This is current program under ASP, I am converting to ASP.Net.
Visual Basic - Object Reference Not Set To An Instance Of An Object?
Dec 7, 2009I'm receiving the following error in VB.Net."Object reference not set to an instance of an object"
Imports System.IO
Public Class LoginForm
Dim Username() As String
[code].....
Checking An Object's Parent Types By String?
Apr 15, 2011I'm trying to figure out how find an object's type when it is a subclass of another object and I only know the string value of the object's type's name.I created the follwing classes:
HTML
Public Class word
End Class
Public Class noun[code]....
The problem is, using 'GetType' to check pn against a string value, I can only see that pn is a properNoun, not that its parent classes are noun and word.Is there a way to check pn against the string value "noun" or "word" and get back a positive result, indicating that pn is indeed a noun and a word as well as a properNoun?
Visual Basic (Coding) - Child Form To Open Within A Panel On Its Parent?
Mar 2, 2012I have created a (kind of) 'Desktop' Form for the main basis of my program. Basically it is made up of 3 panel controls.
1. Holds all buttons which load the different forms (Like the windows start menu when expanded). name: StartMenuPanel
2. Holds Information on log in deatails. name: LogCheckPanel (very thin panel at top of screen)
3. Main panel which takes up the majority of the screen (where I want the forms to load). name: MainPanel
My aim is: When a button is clicked from the 'StartMenuPanel' the form will load with-in the 'MainPanel'.
I tried changing the start position to 'centre parent', but the panels are in the way so some of the childform is overlayed by the panels.
[Code]...
When I run this I get the following error: 'Top-level control cannot be added to a control'.
I hope I've explained this well enough.
LINQ - Query Children Object If Parent Count Is = 1
Apr 17, 2012I have a the following Class structure. Company > List(of Departments) > List(of Employees) I want to Query a Company to find out if it has a department of the following name and a Employee in that department with the following ID! How could I query this. The way I have the code it expect to return one department so I have it doing
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VS 2010 "Object Reference" Error When Adding Object To List (Of T) Property
Apr 25, 2011I have a class that has a property that I declare like this:
VB.NET
Private _DirectoryList As List(Of FileDirectoryInfo) ''' <summary> ''' Array of directories. ''' </summary> ''' <value>Object</value> ''' <returns>Directory array list</returns> ''' <remarks>N/A</remarks> Public Property Directory As List(Of FileDirectoryInfo) Get Return _DirectoryList End Get Set(ByVal value As List(Of FileDirectoryInfo)) _DirectoryList = value End Set End Property
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List Of T Find Date Or Other Property In A Object In The List - Then Return Found Object?
Sep 3, 2009After reading all the examples for list of T exists and Find and find first, none show how to handle multi-property objects. Below is bare bones example maybe someone could flesh out to show how this should be done.
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim DatePriceList As New List(Of DateAndPrice)
DatePriceList.Add(New DateAndPrice(Date.Parse("1/1/2000"), 10.12))
DatePriceList.Add(New DateAndPrice(Date.Parse("1/2/2000"), 11.12))
[Code]...
VS 2010 Changing Control Parent Property Changes Control Location Position?
Feb 16, 2011I'm trying to make a program with transparent labels over pictureboxes and when I set the label Parent to the PictureBox the position of the label changes.
View 2 RepliesOrder Of Creation Or Adding To The Parent Control Determines Whether Or Not A Control's Dock Property Supersedes Another's
Jun 17, 2010i frequently have troubles with the dock property. it seems that either the order of creation or adding to the parent control determines whether or not a control's dock property supersedes another's. e.g. a control with the dockstyle fill will overlap with another docked control on the same parent. does anyone know what the rules are to determine how docking will behave; particularly in dynamically created GUIs?
View 2 RepliesBind Property Of User Control To One Of The Parent Control's Fields?
Dec 30, 2011If I need access to the value of a user control's property BEFORE PreRender, would I need to base the custom control off of one of the preexisting data controls (repeater, listview,etc.)?One of my user controls features a gridview control that is configured based on the user control's properties on which it resides. Several of the key properties alter the SQL Statement for the underlying recordsource. I'm now in a situation where the property that sets the WHERE statement for the SQL Statement needs to tied to a value in the user control's parent FormView. Think of the formview as displaying a customer detail record. The user control takes the customer's account number and then displays data from a related table such as Customer Contact Names. Since the gridview is created before the control's prerender event, working within the prerender event doesn't seem efficient.
View 1 RepliesChanging Parent Property From The "Properties Windows"?
Jan 7, 2010Im always using this code(Example):Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load ToolStrip1.Parent = PictureBox1 End Sub To set the Parent Property of an Object. How can i change it from the "Properties Window"? Just to save 3 line of code.
View 3 RepliesProperty Of A Property Of An Object
Dec 22, 2010[code]I understand the error is saying I've got a null pointer reference happening, but I don't understand why.
View 2 Replies.net - Visual Studio --"object Reference Not Set To An Instant Of Object" Error
Mar 5, 2012"object reference not set to an instance of object" error while creating a new project with visual basic in visual studio.I need to start a new project in visual studio.please respond quickly if u know how to fix this.
View 1 RepliesAccess Members Of A Sub Class Through A Property Of The Parent Class?
Mar 30, 2010This is a bit of a continuation from a previous post for which AtmaWeapon was very informative.
Problem:
A parent class has a sub class with various properties. A property of the parent class is a List(of T) with T = the sub class The issue is how to store data in the sub class of the instantiated parent
Some example code (hopefully formatted correctly):
Code:
'=========== Class Definitions =============
Public Class courseClass
Public Class timeTableClass
[Code].....