I want to create a custom class that has inside an array of another custom class (see my code below) but when the programm runs is crashes. Why? What is the right expression???? Plz help I'm a newbie in VB.net.....
Public Class ctrarray
Public nameclass As String
Public ctrlindex(glvar_spaces) As ctrlindexclass
End Class
[code]....
I want to create a user defined data structure, which will be a 2 dimensional array such that each individual square of this 2-dimensional array will also store the score and the grades. ( Iam using VB.NET) More details:
for example: There is an 2 dimensional array with 3 columns and 2 rows, I want to fill each of the
(0,0);(0,1);(0,2) with their own score (Integer type) and grades (String Type).
And this is same for the rest of the squares i.e. (1,0);(1,1);(1,2) and (2,0);(2,1);(2,2)
After creating such custom data structure: "CustomArray", I should be able to create the instance of this custom data structure (which will be a class) and code something like this:
Dim objCustomArray as CustomArray
objCustomArray = New CustomArray
for i as Integer =0 to 3
[code]....
I have a userControl11 (either in winform or wpf) which has a ValueChanged custom event. If I put it in client form and in form_load set its value to 100, it will trigger the ValueChanged event. But if I set this value inside the constructor of UserControl1 the custom event won't trigger. How can I force it to do so ?whatever the technical reason, functionally it does make sense. If the object is initializing its value from some sources unknown to the client form and the client form has a textbox bound to this usercontrol value, it is sure convenient that it could refresh its textbox at any time including when the form loads just using one single event handler. Without this the client form has to create another initializer for this bound textbox at form load.
Below the source code of my trials in winform:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
[code]....
I have created a class "student" and made an array which contains students.I would not only like to display the array in a datagridview, but the array should also be updated if the user makes changes to one of the students in the datagridview.
I succeeded in showing the array in the dgv: one way is using datasource prop, the other is doing is diagrammatically. However, i can't find out how to let the user edit the array by editing the dgv.
I'm moving my first steps in the VB.NET world (I come from VB6) and I'm stuck with the creation of a particular class.
Let's say we have a bus that always has 101 places. I'm trying to create a class containing the map of the bus, along with methods to graphically represent it.
My "Bus" class will have a couple of properties ("BusColor", "BusModel") related to the whole bus. Then it should have a property called "Places" whose type is a custom class thet represents every single place, along with, for example, the passenger name or the place number. This property should of course be an array.
This is my code so far (simplified):
Public Class BusMap
Private Const MAX_PLACES As Integer = 101
Private _BusModel As String = ""
[Code]....
but I wonder if there is a more standard way of doing this.
My second question is: how can I modify my class to be able to iterate its Places property with the "for each" statement? A quick search on the web showed up that I should implement the IEnumerable interface, but I'm still not enough confident with the concept of Interfaces.
I've been programming in VB.net for a while off and on, but never really had a need to use custom classes till now.I built a function in a module to populate a class, The class how ever is supposed to refer to one instance.I need to create an array of this class but the amount of instances needed is not always known.Works fine till the class goes to populate the class array.[code]It's probably something simple, I've just starred at it to long. Keep gettitng "Object reference not set to an instance of an object."
View 1 RepliesI am working on a project which lets the user edit the students in a certain group using a datagrid. First I created a class called student and then I created a student-array. Displaying the students in a datagrid works fine. On form-load, I change the datagridview.datasource to the student-array. The datagrid has 20 rows by default (Public dbstudebt(0 To 19) As student). When I edit an existing student everything works fine but when I fill something in in an empty cell and press enter or tab to confirm and add a new student, it just clears the cell and nothing happens. So basically, editing existing studs in the datagrid works fine, making new student doesn't work at all as those cells are always cleared immediately.
View 4 RepliesI use this code to create the same Button in multiple Forms[code]....
View 6 RepliesI am trying to create a property of type string array (if this is possible).....and I seem to be lost.
I tried the following, but it says "String cannot be converted to '1-dimensional array of string'" at the return
Private _strZipList As String()
Public Property strZipList(ByVal i As Integer) As String()
Get
[Code].....
Declare Custom Events To Avoid Blocking, with more than one custom event. If I duplicate the Public Custom Event section and just change the event's name, then both events are called even if my code only calls one of them.
Public Class TestClass
Private EventHandlerList As New ArrayList
Private EventHandlerIndex As New ArrayList
[code]....
I am making some changes to a fairly old project.It has a DataGrid with an Inherited Class
Public Class CustomDataGridTextBox
Inherits DataGridTextBoxColumn
and a Override Sub Protected Overloads Overrides Sub Paint (.......What it was doing was alternating the Data Grid Line colours New Requirement is to break up some items in the DataGrid By categories So I have added new lines to the data and sorted so they show up ad category headers (Production Stations) And they would like the Category Header to be a different colour and then the alternating line colours to restart.This did not sound too difficult but that has proven a trap Setting the category header is no problem but restarting the alternating colours is Previously the row was determined to be odd or even to set the colour.Now I am intending to use an Integer to define what colour is used but it persists only for that text box.
How can I get it to extend its life so each call can refer to it and update it and set the desired colour?All I need to do is have an integer variable that will hold its value for the next call?
I'm making a custom class that mocks the System.Drawing.Rectangle class because the Rectangle class doesn't have a name property. I need a name property because I am adding all of my rectangles to a collection and I need a little more info stored than just their locale and size. So I changed the _onPaint event but nothing is working out when I run the program?
Public Class Rectanglar : Inherits UserControl
Public BackgroundColor As Color = Color.Blue
Public Sub New(ByVal name As String, ByVal XY As Point, ByVal Widthy As Integer, ByVal Heighty As Integer)
[code].....
I want to store additional information about a listview item using a custom class, but I can't seem to get it to work.I'm currently using this code to accomplish something similar using a listbox item.I just want to do the same thing with a listview.
Public Class myListboxItem
Public id As String
Public rootFolder As String[code]....
I forgot to add "Inherits ListViewItem" to my class.I'll update the code listed here to serve as an example for others.
Is it possible to create a user control with a list of custom class type property? If it is, how can I? The issue is that, in designer mode the property is not displayed in property window. I can add the list on markup but when i switch to the designer mode it gives an error which is 'The user control does not have a public property named BookList'.
View 1 RepliesI am New to <acronym title="Visual Basic">Vb</acronym>.Net. this is my first test. i try to create small address book. but i don't know what wrong. it compile perfect but when it run it give error and not work. is there any other way to add same class like in class inside array?
[Code]...
I have a map with a MapItemsControl in my WP7 app that contains pushpins bound to items in a collection of custom classes. The pushpins are bound to properties of the item in the collection via a DataTemplate.When an item is added to or removed from the collection, all pins display correctly, with properties as per bindings, but when just an items' properties are modified, the UI does not update. The bindings just seem to get values from the source item upon loading, but I'd like them to keep the UI elements updated when the source collection items' properties are updated.To illustrate, I'll create a similar example:
Heres a custom class:
Public Class Box
Property CurrentColor As Color
Property Location As GeoCoordinate
End Class
[code]....
Whenever I add or remove items from TempBoxes, the pins all render as they should (e.g. if I specify a color in the collection item, the pin shows the color).Tapping on the item triggers the BoxTouched sub, which causes the item's color to change in the collection, but the UI doesn't change (pin color stays the same).To get the UI to update the color, I have to get it to render the pins again, by adding something like this to BoxTouched:
BoxControl.ItemsSource = Nothing
BoxControl.ItemsSource = TempBoxes
I can't figure out why this does not work.
Public arrs(32) As ARR
Public Class ARR
Public nr As Integer
[Code].....
I'm working on a project which needs some third party components prequisites to be installed before installing my .NET Application. Can someone tell me how to do it ?? I'm using .NET prequisites components to install the components like (.NET Framework 3.5,Windows installer 3.1,Crystal Reports) but what if i have some third party components which is not listed in prequisite lists ...
View 2 RepliesI recently had the problem of trying to store an enormous amount of decimal places in a variable. Someone suggested that I create my own class to handle this. However I have researched extensively and can't seem to find a suggestion as to how I would do this. Would I read each digit into a list? How would I get each digit as to loop through a decimal, for example, and add each digit would still only give me 28 decimal places
View 8 RepliesError Unable to cast object of type 'System.Data.DataRowView' to type 'M8_Rating.myItem'.Any idea what the deal is?
Dim MyItems As New List(Of MyItem)
For Each selItem As myItem In lb_forms_SecurityMgr.SelectedItems()
MyItems.Add(New myItem With {.Description = selItem.Description, .Value = selItem.Value})
[code].....
I have some questions regarding the dispose method as per custom classes.I imported a class using the upgrade tool and got introduced to the finalize method and this line of code within:
MyBase.Finalize()From what I have read this method is the class destructor and I should not be using it. Instead I should implement the IDisposable interface.
[Code]...
I need to look at the properties of an object and I cannot instantiate this object in the proper state on my dev machine. I need my client to run some code on her machine, serialize the object in question to disk and then I can analyze the file.[code]...
View 2 RepliesI created a custom class which just stores 3 byte values, (R G B to be exact), which constantly change. So my idea was to store that class in a HashSet, then create a new instance of the class (with different byte values) then add that to the HashSet. There can be duplicates, which is why I decided to use a HashSet, which will ignore an item if it's allready been added. Doing this on a List would be too slow.But I've ran into a problem. Adding a custom class to hashset seems to only allow 1 to be added. I assume this is because its hashing the class object while ignoring the data (byte rgb values) it contains? Is there a way around this? It's possible to convert the RGB to Color and just use that in the HashSet, but conversion is a bit too slow.
View 2 RepliesI have a very interesting LINQ question. I have a document, that I am trying to filter results on, but to filter, I am matching on a REGEX result from one element of the XML. I have the following, working LINQ to XML to get the individual data that I'm looking for.
[Code]...
I created two classes. One class is StudentClass and the other is HomeroomClass. The HomeroomClass contains a readonly property as a generic list of the StudentClass. [code]...
View 6 RepliesI'm trying to add validation to one of my class properties:[code]The value for the golfer's handicap comes from a oombo box on the form. Even if I have nothing set for this property at runtime, my validation doesn't work. I tried putting the If statement under Get instead of Set, and tried mHandicap = value after an Else in the If statement, but nothing seems to work. I'm working in the dark here and can't find anything suitable online. I was hoping to not go down the path of ReadOnly or WriteOnly properties as I'm not at that stage yet, but does this make a difference for my purposes here? Can anyone guide me as to what I'd need to do from this point? If I've got it right, you can add validation in the class and this means that you then don't need to repeat this validation in the form??
View 3 RepliesI have a custom class that simply contains a public variable X.Let's say I have two instances of the class, A and B.If I execute an assignment operator, such as:A = B then I want A.X equal to the VALUE of B.X.But, I'm pretty sure that this will just assign B to the variable A.Assigning pointers, in C++ lingo.I looked in the VB.NET docs, which state that "The operator can be overloaded only as a relational comparison operator, not as an assignment operator."
View 7 Replies Here are essential excerpts for the code creating the class and the page using it:
Imports System.Collections.ObjectModel
Public Class Test (Of T as xyz)
Inherits Collection (Of T)
[code].....
I am still learning vb.net and decided to make a "horse race" to get a better understanding of inheritance and such. So first of all I made a horse class that inherits from the picturebox. I gave the horse properties such as image, height, width, x-position, and y-position. I also gave the horse a speed(between 1-1000). My idea was to have the horses start at the starting line and get them to move using a timer. Each time the timer fires the move method executes. The move method creates a new random number(seeded by DateTime.now.milisecond) between 1-1000, if the random number is lower than the speed of the horse it will "move" adding 1 to the x-position property.
Here is the code for the class :
Public Class Horse
Inherits PictureBox
Private m_speed As Integer
Private m_picture As Image
Private m_xposition As Integer
[Code] ....
Now things work as I expected for the most part, I created two new horses and gave them values, if one is "faster" than the other it will move faster. Here is the code I use to create two horses and put them in an array:
Private thisHorse As New Horse(700, My.Resources.Horse__Small_, 20, 30, 100, 100)
Private secondHorse As New Horse(700, My.Resources.Horse__Small_, 20, 150, 100, 100)
Private horseArray() As Horse = {thisHorse, secondHorse}
I give the horses visual representation using a loop during the load form event:
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
For Each i As Horse In horseArray
i.Visible = True
[Code] .....
The only problem is if I give them both the same speed they seem to move in unison. I have tried adjusting the x-axis increment and have seen them both jump at the same time. Now I realize since they have the same "speed" they should have close to the same movements but wouldn't the random factor in the move method create some discrepancy between the two? I have ran this multiple times and am still unsure what the problem is.
I know this can be done as there are other modules out there that have this, but I'm just not getting it to work.
I have created a custom module for a DotNetNuke site. I want to be able to create a class object within the module to hold the information about that object. I can create the object and everything complies. But when I go to use the object in the code-behind it states that the object is not defined. I'm not really sure where to go from here.
This is the beginning of the View.ascx.vb :
Namespace Modules.VacationForms
Public MustInherit Class View
Inherits PortalModuleBase
[Code].....
I'm really not sure why this is not working. I did download another module code to compare and as far as I can tell everything is the same.