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.
View 2 Replieshow to fill List View and Data Grid from a Database (SQL Server).
View 4 RepliesI have a datagridview with 3 columns.
Now I need to fill the datagridview's datasource with 3 arrays.
Example:
(column1) Username- Joe - Mark - Thomas
(column2) Password - Joe - Mark - Thomas
(column3) Activiated - Yes - No - Yes
Then after i split what should I do? Should I add 3 arraylists in a class or should I use structure and how?
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.
View 7 RepliesI 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 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.
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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.
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I am loading a series of JPG images into an image list then using that to fill a list view. My program is using ALOT of memory by doing this. What would be the easiest way to add the images but take up less memory/time?
View 3 RepliesThis is what I want to do as seen in C#(loop against a list and fill another list from its data using Linq)
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I'm currently building a program where there are two list box's and a button to copy the selected array item in listBox1 to listBox2 in a separate array.[code]
View 2 RepliesI have the following code that simply takes a list (length = 15) and splits it into 3 different arrays (5 items in each). Is there a way to achieve more efficiently?
For i As Integer = 0 To 4 Step 1
COURSE_Course1(i) = TempFullCourses.Item(i).ToString
Next i
For i As Integer = 0 To 4 Step 1
For c As Integer = 5 To 9 Step 1
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The scenario is:
1)A large 2 dimensional array (400,20)
2)The program needs to access particular chunks(for example (0,20) to (50,20)
3)The program will open multiple files and process each into it's own 2D array (400,20)
What I have right now is code capable of creating the array, but no way to store the array so that I can open a new file and process that data into another large array. Someone mentioned the generics List(of T) might be a good way to store each new array as you could use the Add function. I have done some research on the List(of T) class but I'm not totally convinced that is the way to go. I'm just looking for some direction as I've just started on .net this year.
I am making a project (Waiting List) where I am using arraylist(2) therefor I am entering 3 pieces of information.The information in the arraylist is then sent to a listbox
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is it possible to fill a list box from two SQL tables firstname lastname.
View 7 RepliesI am trying to move through a list "TodaysCard" and print the TimeOfDay.ToString into the first column of every row and to only create the amount of rows that are needed. But am a bit of a novice when it comes to this and can only get it to display the TimeOfDay.ToString value for the first item in the list over and over again. Just wondering how I can get it to iterate through each item properly.
For Each Race In TodaysCard
With (Race)
Try
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I need to set up a list consisting of arrays of two elements. Simple, right?
Like: (code snippet):
Dim strDataPoint(1) As String '2-element array
Dim lBiasCurve As New List(Of strDataPoint) 'list of 2-element arrays
Dim lPwrCurve As New List(Of strDataPoint) 'another list of 2-element arrays
But this gives me an error msg on 2nd and 3rd line: type strDataPoint is not defined....
I have a WinForms applciation, I wrote a function that returns a list of all the controls on the form. The function returns a list of control objects.My target is to fill up a combo box with a list of the control names so that once clicked I set focus to it.So what is the correct code for converting a List(Of Control) to an array of string.
View 2 RepliesFill Combobox with List of Control names
View 5 Replieslist the steps to fill a combobox using a bindingsource. I dragged a bindingsource onto a form, created a datatable and datatableadapter(correct term?), added a query. I tried but I am missing something, my combobox displays System.Data.
View 5 RepliesI have a list of(myclass)each item of this list need to be elaborated before being inserted in the list.Is it safe to use parrallel processes to fill shared list where each process has to fill a predefine range of the list? Or is it necessary to freeze the list when one process is filling it? in other words: can many process fill the same list in the same time without problems
View 16 RepliesI have an app that the user picks items from a checkbox list. I have the items selected saved to a seperate db table. I want to be able to have the selected items repopulate as selected if the user reopens the web page.What I've tried:I've pulled the items selected previously back to a hidden list box which works but I can't figure out how to compare what is in that list box with all the items contained in the checkbox list (this is being populated by another seperate table in the db)I've tried just a straight query and used reader but keep getting errors about cast and if I switch it to a GetDecimal, when I try to see what it's pulling, it's not the data but maybe the index: See below:Does anyone out there have a sample of can help me figure out how to just have this stupid checkbox list reselect the items that the user previously selected and saved to the db?
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I am trying to make a database, fill it with tables and then fill the tables. I am having problems connecting to the server and am really not sure why. I have posted this thread in two areas of this site because I was not sure what was the best area to put it in. [code]
View 3 RepliesI have 2 linked DB tables, Artists and Albums using ArtistID as the primary/foreign key.When I want to add a new Album, I have a new form open and I can fill a combobox with the list of Artists to choose from and edit all the details then save to the database.
However, when I want to edit the Album info, I can't seem to get the Artist associated with the Album, as well as all the rest of the Artists from that table, (in case I need to change the Artist associated with the Album).The information required comes from 2 linked tables, so that's where I'm getting lost.An example of this is when a person edits their profile on a webpage, for instance, a list of countries is usually listed in a combobox and the one selected is the country they selected when filling out the form previously, however, they still have the option to change it.
I have created a form which has two things a list box and a button which is labeled "Input Values"The user should click "Input Values" and a new form will appear. This new form will ask the user to enter 10 values into a textbox and click ok after each value. These values are to be stored in an array and displayed in the listbox on the previous form.I am having trouble getting the values of the user to store into my array and displaying into a list box. I have this so far.
Private Sub OKButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OKButton.Click
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I want to create a login system that reads the usernames and passwords for a list of arrays:[code]I have managed to code the program so it accepts the correct username and password and sends a error message when they don't match. The problem I'm having is when the user enters a username that isn't on my Username list. The program always crashes when I enter say "admin1000".[code]
View 3 RepliesI have read many posts on this topic; among them and most recently .NET - Convert Generic Collection to Data Table. Unfortunately, all to no avail.
I have a generic collection of structures :
Private Structure MyStruct
Dim sState as String
Dim lValue as Long
Dim iLayer as Integer
End Structure
Dim LOStates As New List(Of MyStruct) I need to fill a DataTable with this list of structures but have no idea how to go about doing this. I am using vb.net in Visual Studio 2008.
having trouble understanding databases in visual 2010.
I have a database, which is loaded into a table adapter when the form loads. I want to assign each column of the table adapter into an array
I want to create a relational database in VB2010 and I am attempting to accomplish this goal by creating a structure of records to be stored in a Random Access File.For each record, I want to organize each fixed-length record so that 4-integer sets of data are stored into a a multi-dimensional array.But when I try to write the code below at the module level, I get an error.
Structure PictureDat
'len= needed for Open
of Random Access File [code].....
Since I want to read/write/save the data in this structure to a Random Access File with a fixed record length size, I need to exactly specify the size of the record...which is, of course, determined by the array's dimensions.If I could accomplish this strategy, then I could search this random access file for a match of search criteria consisting of 4-integers with any of the 4-integer sets of data in each record and thus find, edit, delete and search records...therby retrieve information from my database.
Is my program design inefficient? Is there a better way to handle perhaps hundreds of thousands of records? The IDE keeps telling me that I am using a deprecated method of file I/O when I use FileOpen(), FileGet(),FilePut() and should be using MyFile.I am entirely comfortable with my time-tested method of data storage that ensures the security of disk storage while exposing only one record at a time to the PC's volatile RAM, thereby not allowing all my data exposed to possible memory corruption on a PC left on for hours, which would be the case if I loaded the whole file as a monster- sized string or stream. Also, these older file access methods allows my code to run on PC's with modest amounts of memory.
I want to make fill my database with 2 fields.1) a specific word2) the definitiontherefore I am using a blank database program in Microsoft Office Access 2007...the blank database has 3 fieldsIdfield onefield twofield one will insert the wordfield two will insert the defintionmy question is this:does the database grow dynamically with the insert or do I have to specify how much memory?
View 2 RepliesI am having a problem with filling a combobox with unique values.Im not very good at vb either so I will explain what I have done so far.
1. I added a combobox to my form called Combobox1
2. I clicked the little triangle widget thing on the ComboBox1 set the dataset to MyDATASETDataSet1
3. Display Member: CurrencyCountry, Value Member: FCode, Selected Value = None
4. I fill MyDATASETDataSet1 when the form loads using:
PricesTableAdapter.ComboBoxQuery(CurrencY_DATABASEDataSet1.Prices)
ComboBoxQuery =
SELECT DISTINCT [CurrencyCountry], [FCode] FROM [Prices]
The form does not load, i get the error: Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints.If I replace ComboQuery with Fill Query (which is the default fill command) it displays results....but not unique results, i see the same items being repeated throughout the list in the combobox.I guess my questions are:
1. when you fill a dataset do you need to select all the fields when you are creating your query?
2. if i simply wanted to perform the following lookup:
SELECT DISTINCT [CurrencyCountry], [FCode] FROM [Prices]and set the combobox Display Member: CurrencyCountry, Value Member: FCode how would I do this in the code?
3. how can i change my query to display only unique values, distinct doesnt seem to be working?