I have the following...
Dim a as long
Dim b as long
Dim c as long
[code].....
The result is different comparing i calculate it using a calculator or Excel....I tried setting variables type of Integer the result is still wrong....
I have a function in VB.NET that loops through values and attempts to convert it to a decimal if IsNumeric is True,
Dim Value As String
If IsNumeric(Value) = True Then
Rate = CType(Value, Decimal) <--- bombing here
End If
I've found that when the function receives the value 603E43 IsNumeric evaluates to True for some reason and then bombs on the conversion. Why would IsNumeric be true in this case?
StudentId Marks obtain class
1001 76 NINE
1002 75 NINE
1003 55 NINE
1004 62 NINE
1005 38 EIGHT
1006 56 EIGHT
1007 31 EIGHT
1008 57 NINE
1009 48 EIGHT
1010 55 NINE
1011 49 NINE
1012 49 EIGHT
1013 27 NINE
1014 31 NINE
1015 48 NINE
1016 58 NINE
1017 31 NINE
1018 36 NINE
This is my database now I want to calculate rank from above this. I call this through procedure. If I select id 1001 then it will display the rank from the above data base. If I select 1007 then it must display rank to class eight.
Im writing a program and its pulling data from a .MDB to put in a .DAT file.
Here is my while loop:
vb
database_connection()
sql = "SELECT * FROM tlalist"
[Code].....
In my database there are currently 6 rows. and only 1 row has the TLA_DAY column equal to 1, but for some reason when I look at the .DAT file it creates it outputs the result twice rather than only once.
Once JTLA_count increments it becomes "2", but the while loop still outputs as if its still equal to "1". Ive used breakpoints and the counter is incrementing fine.
Anyone else have an issue using read, It appears when I use read it gives me the correct buys but returns the wrong integer value So I use it and it fills the Array i make with &h10, &h6 but read reutnrs number of bytes returned to 1. if there a better way to go with Vb.net with RS232 I mean really my projet dosent have anything out of the Normal
Friend WithEvents CashValidator As System.IO.Ports.SerialPort = New System.IO.Ports.SerialPort("COM1", 9600, IO.Ports.Parity.Even, 8, IO.Ports.StopBits.One)
CashValidator.Read(MyResponce, MyResponceLen, 4)
I am trying to add 2 variables and the result to appear in a label.The case is that there is a platinum version of an album which costs more. The extra cost depends on the album so it varies.If the user wants to purchase an ordinary and a platinum album then I must add the two variables and the combined price to appear in a label. The normal and platinum prices appear fine when the other is zero but when I increase the quantity on both the label remains blank.I have an if statement like this:
If PriceNormal >0 and PricePlatinum = 0 Then
lblPrice.text = PriceNormal.ToString("C")
End If[code]......
I've got a DataGridview I want to remove columns from as it greatly increases performance when I format the DGV. The first time I remove columns in a loop (using the removeat) property, everythings fine. But when I try to remove more columns in another loop, it appears to remove the wrong columns and displays the wrong data. In other words, it displays the wrong data and headers; and the columns it does show has headers and cells that don't match.
[Code]...
I am currently having a headache on how to solve this problem that i am facing. here is the situation: I have a combobox and a list box on the main form. The combobox will get the data from the ms access database. In the database, i have the details of a person's IC, Name and DOB say for eg on one entry I have D215311523C,SHAWN,13/04/1987 So now, my combobox on form load will show the list of dates in the database to allow the user to search base on the date itself by clicking on the selected date. So when the user clicks on the particular date say 13/04/1987, people in the database whose birthday is 13/04/1987 will be shown on the listbox.Meaning to say if i have 3 entries whose dates are the same 13/04/1987, 3 entries will appear. If there is only two entry, then two results will be shown. But now, when i do a single click on the date, one result will be shown. That is correct. But the problem is when i click on the same date again, three of the same results will be shown on the list box. that is it will display : 13/04/1987 13/04/1987 13/04/1987 which is not the case. Then it will show more duplicates of the same results if i click more times on the same date which should not be the case.
Dim n As Integer
Dim numbers() As Integer
Dim StartFrom As Integer
Dim EndAt As Integer
[code].....
I am using a datagrid in my where i am having four columns. In first column the parameter values are entered and in the second column measured value is entered and in third column the nominal value is entered.Inthe fourth column the result is displayed by subtracting the measured value and nominal values. I am doing this calculation in Datagrid cell validated event. What i want is,there will be many rows in the grid,when typing the value in the third column the corresponding result will be displayedin the rowof theresult column,save button will be displayed while the form loads,when the calculate part is completed that is there should not any cell of the resut column empty then i should enable the save butto.
View 2 RepliesI am encountering the following issue So i have a device that sends stuff at the serial port, i then parse it and put it into an array of bytes like that:
Dim HCI_Command_Rcvd_Byte() As Byte All good till here What i wanna do is make an array and put this result every time the serial port gives me a new result, for example:
[Code]...
Basically what i wanna do is let the port parse the messages, fill in the array with the result at an empty spot in this array and then i will have a separate thread that will look in into this array in each non empty space and after it looks into the non empty space it will use or discard the info and also mark this space as empty (after it checked)
I just read about DataSet in VB.NET, it uses disconnected concept. My question is: if my apps has "List All" button that query data from 1 table in the database, and that table has "very very very" many rows, so my DataSet will be filled with those data and eat up memory. Can I limit the data that being put to the DataSet from that query? But I want to be able to retrieve the next data from the same query if the user want to see it?
For example:
I have 1000 rows in my database, and i query all of them. But I just want 200 rows being inserted to my DataSet, but if the user want to see rows number 201 and so on, I want to be able to retrieve the next 200 rows, and so on. So it just like cutting those data into a group of 200 rows. Can I do this with the concept of "disconnected" of the DataSet?
Last year (2010) I came across a FANTASTIC command that allowed me to take a string of variables with a common delimiter and break it all back out into separate variables (possibly an array) with one statement.
[Code]...
As long as the delimiter was a unique specifiable character, this one-statement command could break it out into elements. my memory and point me in the right direction.
I have code, shown below, that works all except for 1 thing: The variables being passed byRef get passed, but once modified in the else section of the "if me.invokerequired" code of RecordData, the variables are never updated in the calling function. To reiterate, the calling function does not receive the updated data that is in the variables custid and amt.When debugging, I see the data change in the else section of "if me.invokerequired", but once it returns from the callback the data is missing.[code]
View 15 RepliesI define some global variables of a class as follows:
Private Class MyClass
Private var1 as Decimal
Private list1 as List(Of string)[code].....
But I found that after this form is closed, all above variables, var1, list1, list2 still exist in memory. I thought they should be collected by gc since the form is already disposed as I confirmed.
Add: I have monitored half an hour after the form is closed. But these variables are not collected by gc. I have an automatic update procedure on the form which uses above variables.Since the above variables still hold values, the automatic update procedure is always called which causes exception. (One quick fix is to check if form.isDisposed in update procedure. But I do not think this is elegeant. Besides, these variables occupy memory.)
I have set up a method in vb.net and in xcode for encrypting a string using as far as i can tell the same parameters for an AES encryption.I've looked all over the place but cannot find information on whether they use the same encryption algorithm and settings.
this is the vb.net code:
Dim encryptAES As New AesCryptoServiceProvider()
Dim encoding As New UTF8Encoding()
Dim encryptor As ICryptoTransform
encryptAES.Key = encoding.GetBytes("12345678901234567890123456789032")
encryptAES.IV = encoding.GetBytes("1234567890123416")
encryptAES.Mode = CipherMode.CBC
[Code]...
Does the memory used in declaring variables are reclaimed by the OS when these variables go out of scope?Does the memory used be released by setting thier value to nothing? if not, then how can I force the garbage collector to run or excecute at a certain/desired time..How about in Windows Forms..How can we make sure that the memory used in initializing and showing forms be released if those forms were closed?
View 13 RepliesQuestion 1: What is the difference between "Background Worker" and "Worker Pool" as indicated within the MSDN samples provided.
Question 2: I noticed while using, AddressOf _Function_, variables cannot be passed; what would be an efficient solution to this?
Question 3: While using multithreading is it required to invoke before setting variables, or only form properties?
Question 4: While using System.Net.Sockets is it safe/efficient to use Application.DoEvents while waiting for new data; or would be using a Do While loop be fine without DoEvents since the action would be multithreaded? Note: there can be up to 2000-3000 sockets in use at a time.
I'm new in .NET programming.I have a class Form1 that includes Button1_Click event.Button1_Click creates a multiple Text Boxies at run time)Here is the class:
Public Class Form1
Dim shiftDown As Integer
Dim counter As Integer
[code].....
I am trying to figure out how bitmasks are calculated in vb... I have the following constants and their bit values:
[Code]...
I'm really new to VB. This is only the 3 app I've created, and I'm stuck.I need to code an app that displays total commission earned on sales at different levels. The commission percentage goes up as sales go up.
Should I write a If/else/else/else/else/then statement or something else?There are 5 different commission levels in the problem. I have my interface designed, but obviously that's the easy part.
I understand the basics of using VB.NET, what I don't understand is what I need to tell the computer to do. I'm supposed to create a subprogram to calculate the greatest common factor and another subprogram to reduce the fraction from the answers retrieved from the first subprogram. My teacher said something about using Mod to calculate it, and also attempted and failed to explain ByVal and ByRef parameters. I don't even know where to begin other than the parameters I have for each, and even those have a high chance of being completely wrong.[code]
View 1 RepliesI,ve completed a program for a debt solution agency that calculates the amount a client can afford to repay after all his deductions and general life costs, my proplam however is at the end when i have to display all the creditors on a proposal data grid that shows the amount and total months to repay all creditors and calculates the amounts as one of the creditors debt is paid up and that monthly installment is devided between the remaining creditors.
View 1 Repliesi have the code below and i want to calculate the next working day adding five days from today and it must not add weekends as a working day. this code currently adds weekends as well and i need it tofclaculate excluding weekends.
[Code]...
I have a project that I'm working on and we are basically creating a calculator to calculate area of a rectangle and area of a circle using one button. How do I code to allow the button to calculate both the area of the rectangle and the
View 16 RepliesCan someone help me figure out why my calculations do not come out right? I have many notes so it is easy to understand. The assignment is: "Create a windows app for the rental of a vehicle. User selects number of rental days up to 7 days. The user also 'can select one of three types of vehicles. Customer has a choice of filling the gas tank themselves,'or prepaying for a full tank of gas ($52). If vehicle will be driven by more than one driver, a multiple'driver cost of $22 per day will be added to the cost." [code]
View 4 RepliesThe interest is compounded monthly and these are sample inputs and output.
Input:
Monthly Deposit: 300
Annual rate: .05
[code].....
I am trying to use and display calculations from various text fields, however it is appending the values. I think it has to do with it being a String Variable and not a Value.. here is the code
Private Sub btnTransact_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnTransact.Click
If rb1Deduct.Checked = True Then txtp1Amt.Text = (txtp1Amt.Text - txtTransact.Text)
[code].....
I have three GPS antennae on a boat. They are in fixed xyz positions relative to each other. For example:
[Code]....
I am working on this program that is suppose to display the patient's bill after they have selected a service at a dental lab. the problem I am having is that if the patient name is empty it gives me a message but it still shows the bill. Also I am having a problem with the code that will calculate the bill if a a patient choose more than one service. Here is my code below
P
ublic Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSubmit.Click
[Code].....
I have probably not a unique issue but I can't seem to figure it out. I need to calculate a datagridview column after it a new row has been added to it. I am adding the row to the datasource and the row is added to the datagridview but how can I automate the two thing together by a single button click. IE: add the row (with a value)to the gridview and then calculate. I have this code but is doesn't work.
Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
Dim OwnerID As Integer
[code].....