I know how to run through iterations using a counter. In my current application I need to iterate throughspecific users from a table, get however many rows are there for that user, write a table and email message (table and
View 1 RepliesI am using VB2008 express edition. I have this code:
'Age = 3 Iterations
Age = 3
Dim Myarray1(2, 3) As Integer
[Code].....
These 2 ways of working both work, but I'm wondering if there's a difference in performance:
Dim collection As ItemCollection = CType(CellCollection.Where(Function(i) i.IsPending = True), ItemCollection)
For Each item As Item In collection
'Do something here
Next
and
For Each item As Item In CellCollection.Where(Function(i) i.IsPending = True)
'Do something here
Next
I thought the second one was better as you'd have a variable less and looks cleaner, but on second thought, I'm not quite sure what happens when you put a linq query in the iteration.
I am trying to loop through an array and perform an httpwebrequest in each iteration. The code seems to work, however it pauses for a while (eg alot longer than the set timeout. Tried setting that to 100 to check and it still pauses) after every 10 or so iterations, then carries on working.
Here is what I have so far:
For i As Integer = 0 To numberOfProxies - 1
Try
'create request to a proxyJudge php page using proxy
Dim request As HttpWebRequest = HttpWebRequest.Create("[URL]")
request.Proxy = New Net.WebProxy(proxies(i)) 'select the current proxie from the proxies array
request.Timeout = 10000 'set timeout
[Code] .....
I have tried a using block, eg:
Using response As HttpWebResponse = request.GetResponse()
Using sr As StreamReader = New StreamReader(response.GetResponseStream())
Dim pageSourceCode As String = sr.ReadToEnd()
'check the downloaded source for certain phrases, each identifies a type of proxy
[Code] .....
Does the try catch statement automatically close the response, or do I need to put something in Finally? If so, what? i cant use response.close() because its declared in the try block.
I need to loop the "buttonOneClick for one second iterations. The program will send a "P" character, wait one second, send a p, wait one second, etc... Also I need to write the information it receives to an excel spreadsheet.
Here's what I have:
Public Class Form2
Dim buttonOnePush As Boolean = False
Dim buttonTwoPush As Boolean = False
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
' Send strings to a serial port.
[Code] .....
I'm trying to implement parallel computing using .NET 4 on an asp.net website housed on a clustered server consisting of 6-8 dual core servers. My original script contains two nested For...Next loops iterating through a range of values in a grid of x by y.
For each point in the grid (x,y), we should perform a computationally intensive subroutine called MakePartsMatrix which accesses a SQL server database with dataviews and manipulating the local variable "unfilled" which is passed in ByRef.
Without the parallel implementation, the nested for loops work fine except its slow -- taking about 60 seconds to run.
When I parallelize the outer For loop, the script is about 50% faster, completing its calculations in 20-30 seconds which is great. However, I have noticed that the parallelization causes random parts of the grid to be either completely skipped (eg, grid (1,5) is never evaluated by the MakePartsMatrix), or some points in the grid (eg, x=10 & y=5) to be evaluated multiple times, resulting in duplicate work.
When I parallelized only the inner For Loop, the script execution time also improves by 50%, but now the last row (y-1) in the grid is skipped entirely and the results in "unfilled" are completely wrong.
When I comment out the "MakePartsMatrix" subroutine, the parallellization (either inner or outer For loops) does appear to visit every point of the grid (x,y) once, and only once.
Dim ConcurrentListofResults As ConcurrentQueue(Of FindBestResults)
ConcurrentListofResults = New ConcurrentQueue(Of FindBestResults)
Dim FBSResultsItem As FindBestResults
[Code].....
Public Class Form1
Dim socleag(6, 6) As String
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'Program is read the file and stores it in the array.
[code]....
I tried to convert this two dimensional to a col and row table. I need help. what I am going wrong with the code.
I've extracted some data from an SQL server, put it into an array, and want to mail it's content to a group of people. All quite easy, until it comes to presentation in the mail body.
When I set it up manually in Excel and do Copy - Paste it looks readable. How do I create a 2D "worksheet" that I can put into the mail body so it looks ok?
I have a small requirement in VB.NET and that is to fill an array with values retrieved from a table. That is I have a table called "user_roles" and that is having columns called "role_id" and "role_name". In the load event of the form, i want to execute a procedure and populate all the items (role_id) from the table "user_roles" into an array.
View 1 RepliesSo hopefully this is a quick fix but for the life of me I can't figure out how to get my results from a OracleDataReader record set.Just trying to get all the users for a specific TNS into an array. I was able to do this easily before with ADODB, but thought I would try using ODP.net.Here is what I have so far and it definitely gets all the USERs for a given TNS. its when I get to the READ() part where the syntax is ??
View 1 RepliesHow can i retrieve the information from Ms Access and put it into a VB.net 2D Array?
View 4 Replieshow do you convert a bidimensional array (of string)
View 2 RepliesI want to know how can I possibly copy a table with multiple columns and rows into an Array or Collection in VB.NET.I want to know the best solution because I want to use the code for 2 different tables and do some comparisons, and the second table has too many records.I was wondering if in VB.NET there is something similar to Hashmap used in java and a table could look like the following
View 1 RepliesI am trying to export the contents of Array to Microsoft Access table. But as of now i could do it via creating a text file in the local HDD. I would like to find a solution bypassing this step.
View 2 RepliesI have been told that the best way to do a search in VB is to fill an array with ALL the records from a table in a database and then filter the records from the array, instead of using the SQL statement Where.
View 25 RepliesI have just started using databases, but I am totally stuck. I made a database and table using MS Access. The table has three columns. ID, Code, and Letter. Basically, the Code column stores a number for each letter (eg. 1 = A, 2 = B, 3 = C, etc.)
Table:
|ID|Code|Letter|
| 2| 1| A|
| 3| 2| B|
| 4| 3| C|
etc.
This table is just for reference for my program, and I don't need to change any values. But I need a step by step guide to link this table to VB 2010 and convert the values of the table to an array. For example: convert the table into the array "example" which means that example(1) = A, example(2) = B, example(3) = C and so on.
is it possible to pass an array as a parameter to a table adapter at design time in wizard in vb.net.
View 4 Replieswhat is the best approach in VB.NET to get the entire table from the Ms SQL 2008 R2 database and save it in the program (dynamic?) array or something which is easy to translate into bytes and send to other device via socket communication?
View 1 RepliesI am very new to programming so sorry for the simple question, but I am at a lose. What the program needs to do is take a user defined starting and ending range, and then build a table based on that range. Inside the table each record will need to have two check boxes.
So for example the user enters in a starting of ABC01 and ending ABC03 and clicks the button the table is populated like this;
[Code]...
I am interested in the pros and cons of data tables and arrays in VB 2010. I programmed decades ago in FORTRAN and used arrays extensively.However, I frequently see data tables in code snippets and don't know when they should be used in lieu of an array.
View 4 RepliesI have a string array that represents the field names for a table I need to create. Given that the first field type is date, the second is time, and the rest are floats, what is the easiest way to create the table? I am currently using the following code, but it seems there may be a simpler, less convoluted way
vb
'read the column names from the OPC server
Dim colNames() As String = GetFileColumnNames().Split(","c)
'build command string used to create the table
[code]....
I want to fill an Array and list box from a table, with ALL of the records.
I DONT want to use Displaymember. Like shown below...
CODE:
This is the code so far, but it is only filling with the first record.
CODE:
I have created several different colored 6 x 9 pixel rectangles (with a white border). I'm placing these rectangles on a large map, based on x y location and color code from a database. As I'm building the database, I occasionally run the program using the Debug in VB Express just to make sure everything is being place in the right location. I started getting an error when my rectangle count got up around 4500.
System.ArgumentException was unhandled
Message="Parameter is not valid."
Source="System.Drawing"
The release .exe works fine with no errors and a count of 6700 ... so far. As it is now it's taking near 60 seconds to place the 6700, and I'll eventually have 10,000 plus. (P4 3.20 GHz - 1 GB Ram). I'm placing each rectangle on the image as I read a row of data. Would it be beneficial to read the entire table into and array and then plot the rectangle?Would I be better off drawing each rectangle as needed or placing a my pre-drawn rectangle ?
Has anybody ran into this error before?
View 2 RepliesI need to fill an array with whole column from database table, so i have used reader to read the values from that column, but can not figure out how to put them into array (code below doesn't work) [Code]
View 3 RepliesThis should be an easy one, looks like I got myself too confused.I get a table from a database, data ranges from varchar to int to Null values. Cheap and dirty way of converting this into a tab-delimited file that I already have is this (shrunken to preserve space, ugliness is kept on par with original):
da.Fill(dt)
' da - DataAdapter '
' dt - DataTable '
[code].....
I want to add a new table in my accdb and copy the content tfrom an existing table into the new one.
Is there an easy way to do this?
I have a data table whose one column is related to a column of another table. I have a listbox in a form which shows a column (which is sorted by another column value by ORDER clause) of the parent table and other columns are in textboxes. The child table is represented by a datagrid. When I add a new item in parent table and click save, the newly created item is listed at the bottom of the listbox violating my ORDER clause. When I wrote some codes to fill data again after updating, it shows an error message[code]...
View 3 RepliesCode.
Public Function comb1(ByVal SName As String) As DataTable
Dim dt As New DataTable
cmd = New SqlCommand("Select Distinct RName from tb_RS_New", con)
[Code]....
While loading the page, the error was thrown as "input array is longer than the number of columns in this table"
I have a database with one table.I'd like to populate an array with the values in the table so that I can work with the data.How do I copy the data from the table to the array?I am able to view the data with a DataGridView but can't find any info on extracting the data to an array or variable.
View 2 Replies