I have a class that inherits from the picturebox class, is represents a gauge. In that class I have an overriden function : [code]and I have on my screen what I expected. But in my form I have a timer that generates a new value for the gauge.[code]For some reason the refresh doesn't work. The gauge doesn't change, the overriden onpaint doesn't get triggerd again. anybody has any idea why?
View 12 RepliesI've been creating short test apps repeatedly to try to understand some of the concepts in VB.NET.For the most part it has been illuminating.I read Bucky's .NET knowlegebase tutorial on passing objects as parameters to newly created forms. He shows how to create a new class that inherits from the base form class and define a New() method with parameters Extending the concept I thought about doing the same thing with a form that was created at design-time (In this case Form2).
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If Class X is within the scope of Class Y, is X a subclass of Y?If Class A is a sub Class of B, then is Class B considered a super class of A?if Class C inherits Class D is Class D a superclass or parent of Class C?if Class E extends Class F then we can consider Class E a child of F?if Class G inherits Class H and is within the scope of Class I then who is the parent of Class G? Classes that inherits Class J and classes that are within Class J are all sub classes of Class J?
View 1 RepliesI am trying to create a class in VB.NET which inherits a base abstract class and also implements an interface. The interface declares a string property called Description. The base class contains a string property called Description. The main class inherits the base class and implements the interface. The existence of the Description property in the base class fulfills the interface requirements. This works fine in C# but causes issues in VB.NET.
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If I have a class that inherits another class in which there are objects that are disposed in the dispose() procedure, do I use mybase.dispose? ex Class A inherits Class B. [code]
View 2 RepliesI need to show two rectangles on a user control which inherits picturebox.For that I have used pictureboxes (so that i can move and resize them), with transparent background. [code]
View 6 RepliesI think I remember reading somewhere that it was possible to assign items to a variable if the item inherited from a base class, but I can't remember how.
I want to have a class that gets properties set and one of the properties is an error code property. I want to assign any exceptions that occur to the property, but it could be any type of exception. I remember that all exceptions inherit from the Exception class.
How can I assign an exception to a property based on the class it inherits from?
I'm extending the ComboBox class in VB.NET and I'm running into a problem prepopulating the collection. I try to do so by using Me.Items.Add() calls in the New() sub. However, once I place the control on a form in the form designer, Visual Studio automatically adds those items to the collection in form designer, then they are added again at runtime. How can I make them only added once?
View 1 RepliesI have a base class called PageBase and then a derived class TestPage that inherits from PageBase. In PageBase I have overridden the OnInit() and when it is called and I inspect the value of 'Me', it is of the type of the derived class and not the base class. My question is how does inheritance really work? For instance, when instantiating TestPage does an instance of PageBase get created too?
Here is my code;
Partial Public Class TestPage
Inherits PageBase
Public Sub New()
[code]...
I have created 3 classes which inherits from(System.Collections.Specialized.NameObjectCollectionBase)
The first class "SQLCommandsCollection" stores "SQLCommands" in a collection.
The second class "SQLTableNamesCollection" stores "SQLCommandsCollection" objects in its collection.The Third class "SQLDBNamesCollection" stores "SQLTableNamesCollection" objects in its collection.
Ultimately I will sit with a "SQLDBNamesCollection" collection which contains all Table names and its respective SQLCommand objects.
I would like to store this "SQLDBNamesCollection" object in my.settings("QueryViewerQueriesPerTableNamePerDBName")
at runtime but I am unsure what this settings type should be.
I have tried system.oject but this does not seem to work as I get an "Unable to cast object of type 'System.String' to type 'Fusion.SQLTableNamesCollection'" exception when I try to retrieve from settings. See below code.
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When I write the following statement in VB.Net (C# is my normal language), I get an "end of statement expected" referring to the "Implements" statement.
<Serializable()> _
<XmlSchemaProvider("EtgSchema")> _
Public Class SerializeableEntity(Of T As {Class, ISerializable, New}) _
Implements IXmlSerializable, ISerializable
...
End Class
The C# version that I'm trying to emulate is:
[Serializable]
[XmlSchemaProvider("MySchema")]
public class SerializableEntity<T> : IXmlSerializable, ISerializable where T : class, new()
{
....
}
I have quickly made up a class that inherits listboxes and uses
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Sometimes in my web applications I used to get this sort of error, I have no clue why is it coming however if I refresh the page few times the page is loading normally.I am using .net framework 2.0 and visual web developer 2005.
View 1 RepliesI have a window service that Inherits System.ServiceProcess.ServiceBase. While running in debug mode (havent tested compiled), the thread does not see the current user credentials. I need the credentials so I can set up the WebProxy and I would prefer to use the account that service is running under instead of passing the user and pwd as a string.Can someone help me figure out why the code running in the class the inherits from ServiceBase does not have have the credentials of the logged in user?
View 1 RepliesI am working on a small desktop form in VB 2010 and am trying to place a pictureBox with an image in it, next to another pictureBox already located on the form when the user clicks a button.
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
Dim tool As String
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But for some reason the newPictureBox with image from "ptext" does not show up on the form. When I specify the new Point to be something like, (50,50) instead of getting the first pictureBox coordinates, the new pictureBox shows up in the right place.
Am I using System.Drawing.Point wrong? Or is there some other error that I'm making?
I'm getting 'Catch' cannot catch type 'Object' because it is not 'System.Exception' or a class that inherits from 'System.Exception'. and 'Expression detected' Code underlined in blue: Catch obj1 As Object When (?)
Private Sub OpenJAMem()
Dim num3 As Integer
Try
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I'm using a picturebox class and the picturebox won't display on the form after I set the enable & visible properties to true. This is a form class "fmMnMn"
Public
Class
fmMnMn[code].....
In this module I set the properties to display the picturebox, but the picturebox wont display? I havn't set a picture to the picturebox, all I want is to display a color(clr.Gry16 is White) in the picturebox and the user interacts with it.
I have three classes Employee, Manager and Salesman. Manager and Salesman classes inherits Employee class.
Employee :
Public MustInherit Class Employee
' Field data.
Protected empName As String
Protected empID As Integer
Protected currPay As Single
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Manager :
Public Class Manager
Inherits Employee
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Salesman :
Public Class Salesman
Inherits Employee
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Now I have created a object of salesman and manager using the following code:
Dim objSalesMan as Employee=new Salesman("xyz",1,2000,5000)
Dim objManager as Employee=new Manager("abx",2,5000,"production")
Is this a good programming pratice or should I use:
Dim objSalesMan as new Salesman("xyz",1,2000,5000)
Dim objManager as new Manager("abx",2,5000,"production")
if I have several of these movable PictureBoxes added to a Form (Form1) and want to display a selection rectangle only on that PictureBox, that is just selected,then I think I should use a flag to mark whether a PictureBox is selected or not. The flag could be used in paint event to decide,whether the selection rectangle is to be drawn or no .To add a flag property to the new class is no problem. But how can I set the flags in all other existing instances of the class, when it is set to True in the selected PictureBox?
I want to read a number of items from a file and then associate each of those items with a new button at run-time, so that when the user clicks one of the buttons I can display some information about that item.Can I use a LIST to manage these buttons and items? Can I create a new class and have each list item of that class, such as 'btnID', 'btnText', etc... ?
View 2 Repliescan someone please help me with a textbox? I have created a new class and require this textbox field within a sub in the new class but i get Error1 'TextBox1' is not declared. It may be inaccessible due to its protection level.I have tried MyClass.TextBox1 = Form1.TextBox1 but I get declaration expected.
View 23 RepliesI'm translating from C# to vb.net and this flags as an error: Classes can only inherit from other classes.
on this 3rd line:
Namespace Microsoft.Expression.Web.AddIn
Public MustInherit Class DocumentEventHandler
Inherits HTMLDocumentEvents
Implements IDisposable
Any idea where this class is? Do I need to import
This is the whole code:
' Copyright (C) Microsoft Corporation. All rights reserved.
'
' Description:
' AddInDocEvent handler - Subclassed from DocumentEventHandler with
' the document events the add-in cares about overridden
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I'm not understanding why its not seeing any of the objects or methods under Microsoft.Expression.Web.Interop.Designer ?
In another post entitled "Creating a button in vb that could get the path of any file/folder or application in a textbox" some code for creating a FileTreeView control is given which starts
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I have a template form with a tab control. How do I change tabs on the form that it inherits from? Do I need a different technique?
View 7 Repliesinherit from two classes in VB.net?We are developing Custom User Controls that inherits from say System.Web.UI.WebControls.Label. We are planning on implementing a bunch of these controls but they will share mostly the same additional properties. We are hopeful about centralising these properties.I have looked into interfaces but it seems they only 'contract' properties you need to implement.
View 2 RepliesI'm trying to get the ATM Class to Instantiate on the Form class.
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ISSUE = " 'ThisATM' is used before it has been assigned a value. A Null reference exception could result at runtime"
The Other problem i am having is with a class in the program called CardReader. What am i supposed to type to let the code below be able to "read" the read function on the Form1?
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Haven't coded in a while, and ran into a wall when setting up my program data structure
So I have something like this in a class file;
Public Class X
Public Stuff as Integer
Public Stuff1 as String
[Code].....
I want to structure my program this way, what's the best way to go about that?
I want to access multiple data types in the same array from within a class, as it should be a subset of my base class etc... and want to be able to change the size of the array
Or is this class array within class nesting a dead end?
I want to create a class that will "search" for something. Basically I load up the "search item" when the class is created and inside the class is logic to do the "search". The result of this logic will be more "searches" that I want to start. How can I have the logic in the class create another instance of the class itself?
View 3 RepliesI need to convert the following code, so that it exists as a created class "Payroll" that utilizes "Get" and "Set" elements. Unfortunately, I'm completely lost.
Public Class frmPayroll
Private Sub frmPayroll_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
[code].....
I want to create a User-Control that inherits the functionality of a TabContol.
I begin by starting a new project of the type Windows Form Control Library. Next I place a TabControl on the UserControl designer surface and Dock the TabContol to Fill the UserControl.
I go to the code editor for the UserControl and enter the following line of code.
Inherits System.Windows.Form.TabControl
Then I run the program and get an error. Intellisence recommends that I use one of two recomendation. When I accept the recommendation I and try to run the program the problems esculate.
The design-surface is no longer accessable.
I try to comment out the problem lines of code in the UserControl1.Designer.VB file but that doesn't help.
How can I create a UserControl that Inherits the Properties of the TabControl so that the properties of the TabControl are visable in the Properties Window?