DB/Reporting :: Lost On Dynamic Arrays - How To Fill & Check
Jun 10, 2009
I guess I'm the newbie. I've just started trying to learn Visual basic 2008 express edition. I'm an old cobol mainframer and I'm having a hard time understanding this language. My project is to read a log file looking for claim numbers and I need to check that each claim has a start record and an end record. I need to fill up a dynamic array because I don't know how many claims there will be. The array needs to hold a unique claim#, a start claim flag, an end claim flag.
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 ...
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
I have an APP that reads data from MS Access tables. It all works fine except that the numbers in Access table are formatted like 800001 so when the user puts "2" in the access table, it changes to 800002 and so on. I want to read the data AS THEY APPEAR in VB.Net but it reads them without the special format. So I get 1 or 2 etc.
I know how to format the data within VB but I don't want to hard code that as the format in MS Access might change. Is there anyway I can read the data format in MS Access ?
I'm working on a program that calculates 2 things. First I need to fill a 5 x 5 array with random #'s from 1 - 10 and Determine the average of each row, each column and the two diagonals, and the second calculation is Fill a 100 element array with random numbers from 1 - 100 and determine the standard deviation and mean of the random numbers in the array.
My problem is that i am trying to use a list box to display all the data from one column in one table of my database. and so, i dont know how to do that although someone hinted at using an array, i'm just not entirely sure how also when the list of data is displayed i aim to have a 'select' button that will take the user to the record of the selected item from the box.
I am trying to port a program I wrote with old VB 1 and I have many control arrays in the program, and it was so easy to do this in older versions of VB, now I am trying to find how to do this and all the answers I have found are a major productions, to replace something that was so easy to do? I would think that microsoft would make programming easer with each new incarnation. instead they are making it harder. doing away with the DATA and READ statement, now it is much harder to fill an array with a loop, now you have to enter each item in an array ONE by ONE. they did away with the ON statement, I had several ON statements, I had to make complex Select case constructs. to replace a simple one word statement?
To make an array of controls in OldVB all you had to do is Name a Second control the Same as the First, and a dialog pops up and ask if you want to make an array, you click Yes, and that's it, what could be easier than this?
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...
I'm trying to create a dynamic jagged array. That is, one that i can increase the size of at runtime. Maybe its easier if I show you. I have a folder containing a varied number of files. What I want to do is set up a jagged array, with the file contents as the second array. So kind of like this:
However, it throws a System.NullReferenceExeption when I try that. In addition, I don't understand jagged arrays all that well....Here is my code (that doesn't work). The jagged array must be accessible by other methods.
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.
how to do something similar to what was a control array in VB6 in .NET? I would like to be able to fill the contents of several text boxes using a FOR NEXT loop or something similar..... corresponding the contents of an array with the texts of an equal number of text boxes.
In the player vs computer tic tac toe game I've been working on there are 2 boolean arrays (one for the computer and one for the player) that track which cells have been taken. When all other moves have been exhausted I would like the computer to play a random cell. To do this I am trying to gather the indexes of all False values from the 2 arrays and add them to another dynamic integer array. The computer will then choose randomly from the new array. The two Boolean arrays are plyrTaken and cmptrTaken. The dynamic array is occupied.
Here I declared the arrays: Public Class Form1 Private occupied() As Integer Private plyrTaken(8) As Boolean Private plyrPairs(14) As Boolean
Here I got the dynamic array ready for use: Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load ReDim occupied(0)
And here is the code I have attempted: For index As Integer = 0 To 8 If plyrTaken(index) = False And cmptrTaken(index) = False Then ReDim Preserve occupied(UBound(occupied) + 1) [Code] .....
In the last block of code I was just trying to print the contents of the array to a list box so I could see if it was working. Obviously, it's not. When one position is occupied the list box shows the occupied cell index with a Zero. This really shouldn't be there as I want only taken cell indexes to be sent to array and list box. When a second position is occupied 7 zeros are added to the list box. Kinda shows promise as 9 total cells - 2 is 7 but there should be index numbers other than zero to represent the cells that have been occupied.
Also, the indexes shouldn't keep adding on to the dynamic array I need a way to clear the array and resize it back to 0. I tried adding Redim occupied(0) to the top of the code but that didn't seem to work.
i am in the process of learning myself VB.net (2010 dotnet 4 )And am a litte confused in whats the best way to program what can be called an array.i want to have an array that looks like this,
{{"aap", 1}, {"noot", 2}, {"mies", 3, "boom"}, {"vuur", 4, 7}} now i tried to declare
I have an error at olapAdaptor.Fill(ds).It's out of memory error.I tried to dispose, set to nothing,... but no results. Can someone please look at my code and help me where I do it wrong.The code opens a database and exports all the tables in ascii format seperated by vbtab. The code is working, but now if I have a lot of tables to export.That's where the error bumps out.[code].....
My text file is something like what you see below, and I want to populate the datagrid. Once I populate the datagrid, I'll use that kind of like an excel spreadsheet in the sense that I'll dip in and grab values based on row and column index to display to the user. I will also (on a different form maybe) display the same datagrid to the users so they can sort by column at their choosing.[code]The error I am getting is: Value of type 'Integer' cannot be converted to 'System.Windows.Forms.DataGridViewCell'.
I have 2 databases that I am working with. One is a compant customer database and the other is my personal call log. Now I am creating a front end for the Call Log. I was updating my customer list by Importing 2 tables from the customer database, a series of queries would erase all of my info, take all the data from the imported tables and move it into mine then erase the imported tables.
Im trying to accomplish the same in my VB frontend. I can connect and fill datasets from the customer database. I can erase my tables. How do I take all of this data from the newly created dataset and move it over to my empty tables?
This for a semi-automated application. Basically the user provides a list of parameters (entered as an offline spreadsheet). The application automatically selects the required report and logon information. Each line in the given spreadsheet will be used as parameter values for a certain report.Therefore the requirements for this (vb.net) applicaton include:
- dynamically select a different Crystal reports
- each report may read data from different tables from an Oracle database.
An old application of mine that had done something similar and it works normally. Those Crystal reports retrieve data from a SQL server stored procedure. (The stored procedure reads data from Oracle using linked server concept). I do not have to set the logon information dynamically in the vb.net code because every report uses Trusted Windows logon concept. The application can also pass dynamic values to different Crystal report parameters without problems.Then I modify this old application for the required new set of Crystal reports. Because these reports access Oracle database via ODBC and not every report reads from the same Oracle schema, it appears I have to write codes to pass ODBC Dataset and its logon information (the users do not want enter it everytime). The application does not run after the change. The report printout shows blank. Although I can accomplish what is needed by modifying each report to use Stored procedure. But this is not prefered and not a simple task because of the number of reports.I have tested each report and it does run normally in interactive mode.I am not sure if I need to write codes to set the datasource for these 'new' Crystal reports. In my test codes I set the reportsource for my CrystalReportViewer object to an non-typed report. Is there anyone who can show me sample codes that
1) achieve odbc logon
2) select a report dynamically for preview/printing
directly here is the issue:a "OpenFileDialog" on a windows form is made to choose a picture and then insert it into a rdlc report under VB.net 2008 so i need the exact command to access any picturebox in the rdlc report.
i used to do the job under VB6 as the following:Set ReportName.Sections("SectionName").Controls("Image2").Picture = LoadPicture(fileName)
I have an array of boolean data that I'm trying to display on the screen using 144 check boxes. Is there an easy way of updating all 144 check boxes with the data from an array and an easy way to update the array when changes are made to the check boxes?
I am using .rdlc Microsoft Reporting reports. I have a form with one reportviewer on it. What I want to use is a combo box where they select the report and then click generate, and it shows a specific report. I have this code so far that changes the report:
I have a series of checkboxes named cbS1 through cbS20 and I set 'Count' as an integer.What I need help doing is taking the value of count and check the checkboxes that are greater than the count.example: count = 7 so checkboxes 8-20 would be checked.Im not sure how to make an array out of the checkboxes to use in a loop.
I have a code in Save Button, and part of it, a code that checks if the dynamic text boxes that has been created is empty. But when the system runs, it only check the first set of text box and an an message appears "Collection was Modified; enumareation operation may not execute.".
Here's the code:
Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click Try For Each txt As TextBox In TextBoxes2 If String.IsNullOrEmpty(txt.Text) Then
I am making this program that has a loop that goes to a website and fills in a form within the loop. But first, here is my code thus far
Dim message As String = TextBox3.Text Dim loopnumber As Integer = TextBox4.Text 'makes the necessary variables Dim browser As New WebBrowser Dim url As String [Code] .....
But what happens is that the loop runs a few times then it errors on the setattribute line (line 19 above) with NullRefrenceException was unhandled And I have a feeling that it is not loading the page fully before it tries to fill in the form.
I'm working on a project in Visual Basic 2008, a web browser, and I've been looking up how to fill in an HTML textbox, fill in a check box, and click a button, I haven't found anything that works. So I know the names of the textboxes, that I want to fill, the check box that I want to have clicked, and the buttons I want clicked, how would I do this?
