Dynamic Array Of Custom Class
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."
View 1 Replies
ADVERTISEMENT
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]....
View 6 Replies
Dec 18, 2009
I have a For Each block loops through a list of objects, the objects are all instances of a single custom class I have made which has multiple properties.The logic used in this block uses a property of the custom class to do a set action, is it possible to dynamically supply which property it uses in the logic? This will be more efficient and prevent me from having to create this logic over for each property of the custom class.My best guess was that maybe it is possible with reflection, however my searches into reflection have left me more confused.
View 2 Replies
Dec 25, 2010
I have a small problem, classes and threading with classes. The problem I have is a dynamic array variable defined in class. In the code below, when error pauses the code, I can see the data in the correct form but I can't write rigth code that writes the data to richtextbox.
Public Class Form1
Public k() As Integer
Private Class zaratma
[CODE]....
View 4 Replies
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.
View 1 Replies
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.
View 6 Replies
Feb 3, 2010
I am new in this forum, also new in VB.Net I need to create a public class for insert and delete data to database Public Class My_DBFunctions
[Code]...
View 1 Replies
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.
View 4 Replies
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]....
View 2 Replies
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].....
View 10 Replies
Nov 15, 2011
Below you will find a code sample that I have dummied up to try and demonstrate the issue I am having. However, this is just a dummied up piece of code. The actual program has noting to do with STUDENTS or TEACHERS. Basically, the problem I'm having is trying to have a CLASS within another CLASS each of which contain ARRAYS that need to be dynamic in size. The sample has a CLASS called STUDENTS that can have in theory many students, the number of which are unknown to the CLASS. I need to be able to add STUDENTS to the ARRAY programmatically.
The CLASSROOM Class should also be an Array since each TEACHER will have MANY Students. There will be only 1 Teacher for a given classroom but the SCHOOL will have MANY CLASSROOMS. Again, I need to programmatically add Teachers and Students without having predefined Array sizes. The code I have listed below will NOT work but it demonstrates what I am trying to achieve. I want to be able to reference the CLASS by using something like this ...
School(iTeacherIndex).Student(iStudentIndex) = "Rick Smith"
I feel like I should be able to use ARRAYLIST in both classes but haven't been able to get it to work. I've tried DIM'ing as ARRAY and can't get that to work either.If I can get ARRAYLIST to work then I shouldn't need to worry about expanding the array via UBOUND (if it's even possible).The REAL question is "How do I have a CLASS within a CLASS, each of which has ARRAYS that need to be dynamic in nature so they can be expanded as needed? The size of the array cannot be determined ahead of time".
REMEMBER . . . the actual program has nothing to do with Students and Teachers. This was just my way of demonstrating the issue using an analogy that I thought everyone could understand. The actual Class is much more involved.I have purposely hardcoded some values just to make the sample easier to work with. This is NOT how I normally program but is just here to hopefully make things a little more clear.
Here is the sample code . . .
'***********************************************************************************
'***********************************************************************************
'***********************************************************************************
'Here is the code that is in the form - This obviously doesn't work
Private Sub TeacherTestDemo()
Dim iTeacherIndex As Byte
Dim iStudentIndex As Byte
[code]....
View 2 Replies
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?
View 4 Replies
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].....
View 5 Replies
Feb 10, 2012
I have a DevExpress GridView whose cells are painted with a random color based on some condition. Now each color has a meaning and I want to show it as a legend. Number of colors used for each condition may vary.How can I do this. I'm using DevExpress 2009 Vol2, and .Net framework - 2.0 and WinForms?
View 1 Replies
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]
View 7 Replies
Apr 22, 2009
I need to have a dynamic URL preferably from a Test Classformatting this design pattern to handle dynamic links from tests. instead of a constant HomePageURL.
Namespace TestDesign
Public Class HomePage
Inherits IE
[code].....
View 1 Replies
Jun 10, 2012
Create a web browser with tabs and I want to add a "Open in a new Link" Button with a Custom Menu .
The problem is I'm trying to use a Dynamic Control(Webbrowser) created in a class from a local sub (A picture box) on the event click . But i get this error [code]....
View 2 Replies
Dec 26, 2011
I am using System.Collections.Generic List.I created new class[code]but i want "UserName" in "ONE" class property created dynamic.
View 1 Replies
Feb 17, 2010
I have a vb.net class with properties defined as follows:
Private m_Property1 As String
Public Property Property1() As String
Get
[Code].....
View 2 Replies
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?
View 2 Replies
Jan 12, 2010
I am having trouble conceptualizing how to create and load my 3d Array. The Project does the following:
View 6 Replies
Oct 7, 2008
I have BIG trouble trying to understand the decleration and creation of an instance with respect to arrays of objects. Basically I struggle with with this error:
Object reference not set to an instance of an object.
complete the test code I made below, so that I can try to understand it..? Been figthing with this for hours..
Code:
Public Class Point
Public x
Public y
[Code].....
View 13 Replies
Feb 23, 2010
I want to build an array with info from an XML file.
The number of columns is static, but the rows will be increased once in awhile and I want one column to populate in a combobox while corrosponding selectedindex appears in a textbox. I think I can figure that part out, but currently stuck at the array building.[code...
View 2 Replies
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?
View 1 Replies
Aug 8, 2011
How can I create a class so that I'll just call it to my form:This is the code of my Add Text box button that adds multiple text boxes.
Public Class Form3
[Code]...
View 4 Replies
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]
View 2 Replies
Apr 2, 2010
I'm working on a program that has to get a set of images and then scan them to find pixels that match colors in an color array. Anyway I think I got everything working but how to load the images in as bitmaps. See the images are dynamic, they change there filenames so I can't call them with a static call like Dim bmp2 As New Bitmap("c:button.gif").
So I am using a loop to feed the images into an array for bitmap but thats not working, anyway that I can do this as, right now the program gets all the filenames for the images from a text file that is sent in to us. All I need to do is have the program check each image for pixels that match our color list. But I cant get the images into the bitmap array.
View 7 Replies
Sep 20, 2009
[URL]..And put into a dynamic array where each month represents a record in the array with 3 given with C/P, Strike and Settle
The criterion is for every month grab all C/P that have matching strikes thus returning the following for every month. See data below and what I would like to return below. Want to use excel VBA to return the values from array into a sheet in excel. See data below
[Code]...
View 2 Replies
Nov 29, 2009
I created a code that will prompt someone to enter a name and if the name is in the array it should print out the correct integer, but it keeps printing out not valid.
Private Sub btnDisplay_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnDisplay.Click
Dim strSub() As String = {"Jasmine", "Sean", "Devon", "Jontae", "Whitney"}
Dim intNumb() As Integer = {15, 10, 11, 12, 5}
Dim strSearchFor As String
[Code] .....
View 5 Replies
Jun 24, 2009
A project requires to allocate a varying number of byte arrays (buffers).
It would be ideal if the following definition would be possible:
Dim ArrayOfBuffers() as buffer(10000) as Byte
The byte arrays must be ordered sequentially because they have to be written to a file by efficient procedures destinationFile.Write(ArrayOfBuffer(3),1000,1000)
The number of buffers will change during program execution sometimes. Therefore it would be nice to be able to do a ReDim on the data structure when needed.
View 5 Replies
