Error 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 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]....
So I made a Listbox, and also a custom class called "Enemies". I used a Bindingsource to Bind "Enemies" to the Listbox. "Enemies has three properties which are: "Name as String, Health as String, and Dead as Boolean".The thing I need is when I add a Enemy to the listbox, I want the BackColor of the item to either be Red or Green, depending on if the Item.Dead property is false or true.
View 2 RepliesI'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'm designing a small GUI Windows program that allow staff at a cinema to reserve seats for customers. There will be a total of 60 seats in the cinema. I have two classes in my program:-
1.) MainForm.vb - used for I/O actions and user interaction
2.) SeatManager.vb - used to hold and handle the background methods and functions that make the program work
Here is the code for my MainForm.vb class thusfar:-
Public Class MainForm
Private Const m_totalNumberOfSeats As Integer = 60
Private m_seatManager As SeatManager
[Code]....
Basically, when the program opens, the lstReservations list in the MainForm class will be populated with a total of 60 (m_totalNumberOfSeats) entries to represent 60 seats. Each of these seats will contain the index number from the array m_nameList; this index number (+1) will represent the seat number and then in the lstReservations list, after the seat number, I'd like it to contain the respective entry from the m_nameList array. As all entries will be held in RAM, when the GUI is opened, all m_nameList array entries will be empty. As the user uses the program, they can highlight a row in the lstReservations list and then use the GUI textboxes to enter the customer's name which will then be populated into the respective array entry.
how to, when the GUI opens, ensure that the lstReservations list takes all of the blank entries from the m_nameList array and from there, I can highlight a row to carry out further methods on?
I add a object from a custom structure to the listbox. The only thing is, I don't know how to change the name that is displayed in the listbox? Heres my object
[code]...
So when I add it to the Listbox, it displays the "Name" variable.. My question is how to update it in the listbox? I can change the name of the object, but the name in the listbox doesnt change
I've saw many many times lots of custom controls, so I decided to build mine.
what do I need do to do to build a custom listbox control?
I am developing one vb application. In that I have one list box. I want to add different types of Items. Like Different Colored and differently aligned text(Like one item item is right aligned and one more is left aligned). Can you please tell me how can i do the same.
View 2 RepliesI'm loading custom listboxitems in to a listbox.But the problem is that i load over 300 items and it takes a while and the program stops responding.I've tried to load the items in a backgroundworker, but i didn't help.
Note: the Listbox is placed on a Page.
I just started my WP7 programming journey. I need to add 2 text lines as an item to the listbox.
View 1 RepliesHow do I remove custom items for example
ListBox
---------
Text1
Text2
Hi
Ho
Text3
Text4
Gimme
So
Tutorial
TextBox5
And I want to remove all except items that has the word "Text" in it.
This is how I add the 2 textblock to my listbox as an item
Dim StkP As New StackPanel
StkP.Name = "Stack"
Dim txtLine_1 As New TextBlock
[Code]....
But it is always returning the last input of "lblScore_1"
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 RepliesI 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'm trying to build a custom ListBox control as inspired by the 'Audi Infotainment System' on high-end Audi vehicles. The only difference is i would like to have a 'boundary' where when scrolling up/down moves the actual list up or down. Basically, i would like my list to act like a normal ListBox except i would like to show say one or two items above and below normally only visible items.
View 3 RepliesHow would I remove an item from the listbox.. I used the code below to populate using a class with description and value properties.
I cant use listbox.items.indexOf("listitem1") to get index
I cant use listbox.items.remove("listitem1")
If I use listitem.items.removeAt(1) it works of course. How can I get my index in this case?
'Users
Dim IAdapter2 As New ds_SecurityTableAdapters.Security_UsersTableAdapter
Dim usersDT As ds_Security.Security_UsersDataTable = Nothing
usersDT = IAdapter2.GetUsers()
Dim userItems As New List(Of myItem)
[Code] .....
I 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 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 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 RepliesI use this code to create the same Button in multiple Forms[code]....
View 6 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'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.