I had to write a program for my class today(I don't like VB.NET, I like Java though) that created an Exception. Is it good practice to set variables to Nothing at the end of the program? In Java, there is the garbage collector so it will automatically delete variables if they are not used again. I don't know if VB.NET has this so should I keep what I have at the end of my code? [code]
View 10 RepliesI would like to loop over two string arrays but does not work.[code]...
View 4 RepliesI have the following code and i do no know why the program tells me that the variables are not declared.
[Code]...
I can't get my variables in the program below into thier arrays.
Dim lblnumbers(6) As Label, txtweight(6) As TextBox
Dim txtnumbers(6) As TextBox, sngnumbers(6) As Single
Dim grade() As String, g As Integer = 1, weight() As String
[CODE]...
I'm trying to put together a quick program for our database, I haven't touched VB since vb6, and we have 2008 .NET now. my question.
Ideally I'd like to make an array which can hold multiple values...such as
Job[job#].joblocation
Job[job#].jobsupervisor
So there would be a Job array, and then different values contained within that. I can't seem to make an object or whatever which allows me to hold different variables inside it.
I am developing an VB.NET application that reads data from the serial port and tcp socket, then I'm processing this data and store it in Database server. This application will be started all the time as long as the computer is started. On the server there is installed an apache server with some php scripts representing the "visual interface". From there the users can see the readed data from the VB app. The need is when an event appear in the apache server (such as button pressed), some data to be passed to the running VB app, and eventually trigger an event on it. I've considered some variants like start an timer that reads continuously some tables from the database that the php script writes onto, or read an xml ot text file, but I think that this may slower the communication and it is a source of exceptions or errors.
For example: An user opens a webpage, just to say test.php. On the page there is a button. The user pushes the button. The result of pushing the button has to trigger an event on the VB app and cause sending data trough the serial port or tcp socket. OR - The VB app has a timer that scans for pressing the button on the test.php.
I have several threads all relating to this same subject but I have yet got a answer which I could work with. I think most of that is because of my explaining..So..[code]...
View 3 RepliesI am trying to use Bind Variables in my SQL statements which I pass to an Oracle database, but I get the Oracle error ORA-01008 Not all variables bound.[code]...
View 17 RepliesI'm currently designing a mock-up of a customer booking system for a cinema using Framework 4.0. All data at present will be stored in an array and as it's a mock-up, it will remain their (customer name, ticket price etc...) as no requirement to permanently store the data at this time.[code]...
View 1 RepliesI sucessfully write a file containing variables with the following code:
Private
Sub
SaveConfigButton_Click(ByVal
[Code]....
The variables do not populate.
I am creating a very simple game for a project. There is opportunity for bonus marks, and one thing I would like to do is be able to "save" the game. The only thing I need to do is save about 4 variables to be recalled the next time the program runs.
What is the best way to do this?
I have searched Google, and there are ways to link the program to an Access database, but that seams a little extreme. I tried seeing if you can make an XML file to hold them, but I can't really find any good information.
I want to create an array of constant variables for my program. But from everything I read about arrays they are handled by a number. I want to be able to pass back a variable that will hold the name of the constant as well as the value. How would you go about do that.I want to when I type the variable to have the constant name show up as I am typing.
View 4 RepliesI'm creating a calculator in visual basic 2008, and with this calculator I want to implement a feature that can store numerical values in a variable for instance x. Similar to the feature used in most graphing calculator that have the button showing: "STO->". I was thinking on using the My.Settings. But I'm having trouble on it.
View 2 RepliesI have written server code in vb.Net. I want it to read to variables sent by another server's HTTP 'GET' request. For example the first server will send this URL [URL]msgid=$messageid where the values to be used by my server are sender, receiver, msgdata, recvtime and msgid I have written my code but it only reads the address sent by the http server and locates for the file in the server's root directory. I want the server to be reading the variables sent by the other server using the HTTP 'GET' request. My code is shown below
' the web server only accepts get requests.
If Mid(LCase(sbuffer), 1, 3) <> "get" Then
'if not GET request then close socket and exit
[code]....
I am teaching myself VB, and when I try to run this program, I am getting "An error occurred creating the form. See Exception.InnerException for details. The error is: Object reference not set to an instance of an object." If I was to declare the variables inside each event handler, the program runs, but why won't it run when I make the scope public? Seems repititous having to declare the variables in every event handler. [code]
View 7 RepliesI am using vb.net with phpMyAdmin MySql database. While running the piece of code below, the program hangs in the for loop before the variables are assigned values from the data table(dt)...
'Check for appraisal period-----------------------------------------------------------------------
Dim sqlCheckDate As String = "SELECT * FROM tblappraisalsetting where appSetID=(select max(appSetID) from tblappraisalsetting);"
[CODE]................
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.)
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 know that
Public Incognito As Boolean
is a variable called "Incognito" that is class-wide that is a boolean.My question is that is there a form-wide variable form that can like communicate with different forms. So if a variable in form1 is "True" than, how can you make a variable in form2 turns to "True" too?
is it possible by 1 program to save settings to another program without running the program that is being edited?
View 6 RepliesI have text for example:11.12.2009 or 7.8.2004 and how to get three variables, a, b, c
a = 7
b = 8
c = 2004
Is it in VB.NET possible to use variables without the need of use DIM? Now I have to use the variables like this:
dim a = 100
dim b = 50
dim c = a + b
I want to be able to use vars in this way:
a=100
b=50
c=a+b 'c contains 150
I think in VB6 and older VB this was possible, but I am not sure.
This is the updated code:
sql = "INSERT INTO Strings (String_Name, Long_Text, Short_Text, Alternate_Text, Multi_String_ID, Lang_ID) VALUES (?,?, ?,?,?,?)"
Dim command = New OleDbCommand(sql, pConn)
command.Parameters.AddWithValue("@webStringName", "String_Name")
[code]....
I am trying to create and INSERT statement with and OLE adapter. I had it working without paramtersm but now I am trying to add parms and am having issues with the syntax.Here is the code so far...
command = New OleDbCommand(sql, pConn)
sql = "INSERT INTO Strings (String_Name, Long_Text, Short_Text) VALUES (?,?, """ & ptsShortText & """)"
command.Parameters.Add("@webStringName", OleDbType.VarChar, 250, "String_Name")
command.Parameters.Add("@webLang_String", OleDbType.VarChar, 250, "Long_Text")
[code]....
Was just trying to get the first two variables parametrized.
I used to add 2 strings variables and it works but when I tried using VB2008 it didn't work. [code]
View 9 RepliesI got a problem dealing with variables: I would like in an if-then-else following
If FZ1_KaskoTextBox.Text = 1 And Grundwert_Kasko <= 10000 And FZ1_BMComboBox.Text = 9 Then PraemieKasko_KFZ1_Var1 = 169.33 And PraemieKasko_KFZ1_Var2 = 169.33 Else
But the variables don't get filled?! is there any possibility to fill two variables within one "then" ...