VS 2010 - DataGrid Custom Class Array
May 14, 2012
I 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.
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May 14, 2012
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.
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Jan 31, 2011
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]....
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Sep 30, 2009
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.
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Jun 16, 2009
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."
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Jun 19, 2011
I have an array of people stored in a custom structure array... how can i copy this array to a temp array so that the temp array has all the same values as the original custom array?
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Jun 21, 2010
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]....
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Jan 5, 2010
I 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].....
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Jun 21, 2011
I recently downloaded VB 2010 Express so i am quite new to the language, but i have worked with dark basic, which seems to b very similar.Anyway, my problem is that i cannot seem to correctly set out my array of a custom type/class. i am trying to create two arrays, one of available entities and another of selected entities of which the user selects the entities to be dealt with in irrelevant ways. i have creates a button (called test) which adds some entities to the available list and all the entities come back the same value but they shouldnt be as you'll c in the code. i have run the step into command a found that "available.item(#).Name = " will change all of the entity's names.As of current i am working with lists as the array kept asking for a 'new' statement but i couldnt figure out where to put it.[code]
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Jan 22, 2011
custom control, by inheriting the Label class like this
<ToolboxBitmap(GetType(CButton), "img_20_16px.png")> _
Public Class CButton
Inherits System.Windows.Forms.Label
[code].....
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Feb 24, 2011
This is also posted in the database development forum. As I think the same problem could apply to things other than connections, I am posting it here also. I have created a custom class. All methods in this class, I want to interact with a single connection object.
Imports MySql.Data.MySqlClient
Public Class clsRegTester
Private cn As New MySqlConnection
[code].....
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Dec 20, 2010
I have a large text file that I am going to be parsing. Each line can contain a variety of Specific Variables.
[Code]...
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Jan 31, 2012
I was trying to block the closing of a custom combo box popup window in my custom DataGrid. The popup window comes by pressing F4 or ALT+DOWN keys in my datagrid which is getting closed if I press the down arrow for the first time, after showing the first value in the combo box as selected. Next time onwards, if I press the F4 key and down arrow, I can move to any item in the popup window and select the item using keyboard and in that case, the popup window is not getting closed till I press the ENTER key or selection using the Mouse. Is there any specific reason for this behaviour or something is missing in my code part? [code]...
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Sep 2, 2010
I was trying to block the closing of a custom combo box popup window in my custom DataGrid. The popup window comes by pressing F4 or ALT+DOWN keys which is getting closed if I press the down arrow for the first time after showing the first value in the combo box as selected. Next time onwards, if I press the F4 key and down arrow, I can move to any item in the popup window and select the item using keyboard and in that case, the popup window is not getting closed till I press the ENTER key or selection using the Mouse.
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Feb 24, 2011
Im making a class that represents a file. Im making a sub that reads data from one byte array into many properties. Now i need something that returns a byte array but only the first 4. Let me demonstrate because i can't think of a logical way of explaining. "something".substring(0,3) That would return a string containing "som" i need a function like that for a byte array
[code]...
Is there an existing function for this type of thing ? i've looked but didn't see anything that I understood.
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Jul 6, 2010
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].....
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May 24, 2011
I am trying to add datagridview control in my custom control but i failed.I started creating new project[windows custom control library], added datagridview control on it and also added a property naming "DGVMain" which refers to datagridview control.I compiled it.
While testing i find its properties like visible and other working but when i click on columns property it doesn't work. i.e i cannot add/edit columns into the datagridview of my custom control.
Did i miss any steps or do i need to add some more actions?
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Jan 24, 2009
[code] i use this line to fill the datagrid Me.tableTableAdapter.Fill(Me.DDataSet.table)how can i fill the datagrid with a custom query?
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Jul 9, 2011
I'm using a DataGrid to display the below custom classes via a BindingSource, I'm trying to figure out a way to save them to a file either by serialization or by some other method. I've tried a lot, but I think it has a hard time serializing because the Account object has the CharacterList object or something. [code]
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Jun 21, 2010
I am trying to create an list or an array of a class.Here is my "Ingredient" class that I am trying to create a list of:[code]In my "recipe" class, I am want to create a list (or array) and I am drawing a big blank on how to do it. Can anyone point me in the right direction?
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Jul 26, 2011
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?
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May 24, 2012
I have a datagridview (windows forms) that is inside an mdiChild form. The custom format is given by a "for" instance, something like this:
For row As Integer = 0 To .Rows.Count - 1
If .Rows(row).Cells("someNumber").Value = 0 Then
.Rows(row).DefaultCellStyle.BackColor = Color.DarkSeaGreen
End If
Next
So, for every row in the grid that you find, if ther value in the "somenumber" =0 paint the whole row green. Problem is, if I put the form OUTSIDE of the MDIParent - just put frmMyform.show() in my btn that calls the form-, the grid WILL apply the format; If I call it like frmMyform.mdiparent = frmMdi, then frmMyform.show, the grid WILL NOT apply the format.
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Sep 9, 2010
I want to reading in a excel file and extract the sCodenumber sDescription ans the sStatus and store them in a array : StatusComposeArray(5200) As MyCompose. After this I need this array for comparing outside this class. But as can you see the array is defined inside the sub: ReadingIn_ExcelFilesCompose [Code]
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Jun 22, 2010
A c# class's single dimension byte array contains socket level instrument sensor data as per:
public static byte[] frameData
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Jan 20, 2009
It's been a LONG time since I messed with VB, and I'm messing around with VB 2008 now.I'm trying to make a custom class with three variables,
ID (String)
Title (String)
Comments (Array of String)
[code]......
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Jan 31, 2012
I was trying to block the closing of a custom combo box popup window in my custom DataGrid. The popup window comes by pressing F4 or ALT+DOWN keys in my datagrid which is getting closed if I press the down arrow for the first time, after showing the first value in the combo box as selected. Next time onwards, if I press the F4 key and down arrow, I can move to any item in the popup window and select the item using keyboard and in that case, the popup window is not getting closed till I press the ENTER key or selection using the Mouse.
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Mar 12, 2010
What is the difference between using the 'array' class in VB and just declaring an array like normal. In other words, what is the difference between:
Dim numOfTicketsPerDay As Array
Dim intNumOfTicketsPerDay(6)
As Integer
Is there any preference of when one should be used over another?
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Mar 15, 2010
If I make the following array in a push button event and I want to put those array variables in a class array. How do I do that? I am just beginning to learn about classes in vb.net but I am having problems using classes and arrays.Is there any good tutorials on that subject.
[Code]...
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Jun 3, 2011
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:-
[Code]...
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Nov 3, 2011
I have main class of Races with mulitple properties. One of those properties has been defined as another class Runners.
So I have a race with multiple runners and when I try to update the data i get an instantiation error.
For the life of me I can't get it to work.
This is what I am trying to do...
In the clsRace class I have defined :
PublicProperty clsRunner(ByVal index AsLong) As clsRunner
Get
[Code].....
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