I want to pass/use a variable inside a sql statement. The code is the following:
Dim i As Integer = 2
Using Command As New SqlCommand("SELECT Comment FROM Params where id=' " & i & "' ", objConnection)
I tried to pass the i variable by using the ' " & i & " ' but it doesn't work (I am getting an error like - Conversion from type 'DBNull' to type 'String' is not valid. )
Using Visual Basic 2008 Express. I need to pass a variable to another form. Or else make the variable visible to both forms.
View 4 RepliesSay that i have the following code that parse about 20k records from the DB.
Code #1
vb.net While reader.Read()
list.Add(If(Integer.TryParse(reader(0).ToString, 0), Integer.Parse(reader(0).ToString), 0))
End While
And then another code which does the very same thing but it seems to be a little cleaner.
Code #2
vb.net While reader.Read()
Dim storeowner As Integer = 0
Integer.TryParse(reader(0).ToString, storeowner)
list.Add(storeowner)
End While
This is what i am confused about; does the compiler creates a new variable automatically when i use the if statement without strictly declared variable? What approach is better in sense of performance?
I am sure this has had to have been answered somewhere but after looking on the web I cant find anything addressing variables in variables. For instance say I have var1, var2, var3, var4 decalred. How can I create a loop assignment? Something like var & i = "variable 1". So instead of "var1" I have the numeric piece be a variable.
View 2 RepliesI am having a hard time trying to pass the values from a list inside of a class. I am trying to display multiple lines of values from a list inside of a class. My "client" class stores multiple lines of values into a list(of class transaction), with the number value (num) counting each transaction that it adds to the list.
Ex:
Public Class Client
Private m_tranlist As New List(Of transaction)
If CInt(tid) = m_ID Then 'create client tran, add to list
nextTran = New transaction(m_ID, tcode, tdate, ttype, tshares, tprice, value, num)
m_tranlist.Add(nextTran)
num += 1
End If
Now I am trying to display each line that is stored in the list in a label, and I am having major trouble. How do I call the list in my main form in order to display all of the values?
I am needing a way that an if statement stored inside of an array can be executed.I am designing an application that will allow users to input if statements that will be used to determine if certain values are met. The input is saved to an array that I need to be executed later. Is this possible in Visual Basic?
View 24 RepliesI want to make an if statement inside a button. So basically its this Private sub Button1_Click ....
If Button2.click then
blah blah blah
else if button3.click then
'blah blah blah
End If.
How would I do this because I can't seem to solve it with any code of mine, i searced through all the allowed values that vb offers and nothing ...
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim s As New Staff
[Code]....
Basically I am trying to update each record with 2 random numbers each time the button was clicked,my problem now is, the system will update the record but the data was wrong. Example, by right all data should be different (randomly string) but for some row it was updated with same data but in randomly, something row1 row2 row3 has exactly same data for column 1 and 2 then row 3 has distinct data, second time, row1 row2 same data row3 ro4 with different data. It is in random sequence. When I add a MsgBox to do testing in the For loop the data was updated correctly with all different data.
I know that if i have a using block like
using myresource
return 0
end using
myresource will be disposed .
But if my using block is
using myresource
return myresource
end using
Will myresource be disposed?
I am wondering if a similar using block is causing memory lead in the app.
thanks
i have to list views A,and B listview B is inside listview A. i want to pass some parameters from Listview A to Listview B's ObjectDataSource.
View 1 RepliesI'm trying to run an INSERT statement to pass data from a datagrid to a table I have on my database. The problem I have is that the table has 6 columns and the datagrid has only 3. So I only want to pass those 3 columns but I get the error that the other 3 columns does not accept null values. I need to change the columns to accept null values. The other problem it is that I can't pass more than 9 records, if I have more than 9 record on the DataGrid it says "object not set as an instance of a reference" and it only add 9 records if I have more than 9.
Dim RowCount As Integer = datagrid1.Rows.Count - 1
Dim ColumnCount As Integer = datagrid1.Columns.Count - 1
Dim RowIndex, ColumnIndex As Integer
Dim myconecction As String
myconecction = My.Settings.DataSource
[Code] .....
One of the things I loved about VB6 is that you had the ability to tell the development environment to break on all errors regardless of what error handling you had set up. Is it possible to do the same thing in VS2008 so that the debugger will stop on any error even if it happens inside a try-catch statement?
View 4 Repliesif I have the following vb code,
for i = 0 to dTable.Rows(i).Count -1
Dim sql As String = ""
Dim strConn As String = ConnString
[Code]....
ok to start i know very little about VB6 but i am very good in true basic lol (stupid school teaching the wrong language -_-) anyway im just asking you to make the answer as clear as possible because i don't know very much. heres the problem . ok in the above example i have a button that (for my example) can be used to build a house (lol) i then have a variable in the button sub called money which will have 150 subtracted from it when the button is clicked my problem is it say variable not defined when using this button ... i have declared the variable in a module and in form load along with my other 50 or so variables. my question is how do i pass the variable into this sub and then send the new value back into form load so it can be sent into another sub for more calculations.
View 14 RepliesI currently have the following funcion:
Public Sub GetUserAmount(ByVal ConnectionString As String)
Dim command1Text As String = "SELECT Wager FROM Donations1 WHERE DonationId = (SELECTCOUNT (BidCountHistory) FROM BidCountHistory)"
[Code]......
I need to pass a variable by name like this
Dim html_news = "...the news ..."
Dim var = "news"
Dim a = "html_" & var
' content of that variable
How can I do that in VB.NET ?
I am currently trying to teach myself how to program VB.Net in Visual Basic 2010 Express.I've been working on a little project for a while and have hit a wall. Normally I can find what I need online but I am now at a complete loss. Essentially I am trying to pass a pair of variables from Visual Basic (file names actually) to VBA so that I can copy/paste data from them using VBA. What I need is to find out how I can pass variables (in string form) back and forth between VB and VBA
View 13 RepliesI have a Public Sub where I declared
Dim Elev As Double
later under that Sub I have the program go to anothrer SubRoutine that uses the same Elev variable. Within that subroutine I get a Variable not declared error. My book talks about using "Static" but in the context i guess I am using it, it hasn't worked.
What is the best method of tranfering the information from one sub to another.
I am using VS 2008.I have an application that has a variable defined as an Application Setting. I use this variable to define the connection string so I can change the location of the database withour having to recompile the application.My application references a class library. The Class Library is the one that manages the database. The DLL is referenced by my application.How can I make the class library use the Connection String defined as an Application Setting of the consuming application? If I say in the class library:sdRadhaAllied.Schema.Connections(0).ConnectionString[code]...
View 4 RepliesVS 2008, .NET 2, Win XP I need help with passing a String variable from App to DLL?Why: I have App that on UnhandledException needs to call ErrorReport dll, send to that dll some strings like: App name, stack, error... Dll will send through internet this gathered data to me.
I can open Dll, close it, code it, but I can not figure it how to send data to it like VB App name, VB App version, VB App error.message For example I can in my form make a global variable like Public TestGlobal As String and that I can call from anywhere in my app, but how to do it with dll?
[Code]...
I'd like to know, if I have a variable,for example, a string, how to pass its value to my new app domain:
static string _str;
static void Main(string[] args) {
_str = "abc";
[Code].....
i have a dialogbox (dialog1) i will assign the input from textbox a variable to the from1 but i cant do that.the variable in form1 is Dim get_from_dbox As Long i try to assign to it from dialog1 like below it fails form1.get_from_dbox = Textbox1.Text but i can assign to textbox??like that which works well
form1.RichTextBox1.Text=Textbox1.Text I am new programing i know i am wrong .don't know where?
How can i pass a global variable from dll project to a exe file, after this i want to run the exe also from the dll.
View 9 RepliesI would like to create this url blah.com/preview?h=yes
so i can do this
<% if request.querystring("h") = "yes" then %>
jquery stuff
<% else %>
don't do jquery stuff
<% end if %>
I have a grid of NumericUPDown fields. When a value is changed, I want the page to update a label at the bottom of a column - its a total line. Everything works, when the page is updated(a button click), but I want it to update real time. as they are changing the updown value... My question, and I have searched and couldn't find it, how do I pass a variable to an eventclick subroutine? Or make the variable a global variable, so it will work in the eventclick subroutine...
View 2 RepliesI have 2 public variables that I declared in form1 of an application. I am trying to call that variable in form2 and then pass that variable in a sql query. [code]...
View 2 RepliesIs it posible to get a value from a javascript variable and use it into visual basic code without incrusting value on any control.
View 1 RepliesI can't find a way to pass a simple variable from my code behind file to the .aspx page.
In code behind I have:
Dim test As String = "test"
and in my aspx page I try: <%=test %>
that gives me the following error: Error 2 'test' is not declared. It may be inaccessible due to its protection level
I have one form, which the user enters upto 5 websites then clicks go - I have on the second form, the one with the webbrowser. A timer which checks if the web browser is busy then either a green light or black image will be shown along side the assocaited input box on the first form.I am finding it impossible to feed variables into the clock through ByVal, like I would a subroutine or function.
Private Sub ActiveMe_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ActiveMe.Tick
If ((WebBrowser1.IsBusy)) Then
Hey.BackColor = Color.Black[code]....
'Error message says Hey is not declared, as i can't pass it through to timer
The variable Hey is determined by the first form - Which picturebox.I have an if statement which simply says if inputbox one has url enter then Hey = Picturebox1, If input box2 has url entered then Hey= Picturebox2 etc.What I want is the timer to check the page has completed loading or is still loading or refresing and the appropriate green or black to be shown aside url input box on first form.I considered using a sub or procedure to act as a clock (a large for loop with another for loop within it, acting as a delay). But found this slowed down theapp to the point of crashing it.
I want to pass variables from one form to an other. The variables i I need in the second form( called" Hulsview") are :" hulsbreedte" and" hulslengte". To check if the varibles are passed I added a textbox in the second form,called" hulsview" to check the variable" hulsbreedte". The value selected in the combobox on on form1" hulsbreedte = HulsBreedte1.SelectedValue" returns always 0 in the textbox on de second form.
Here is the code form1:
Imports System.Drawing.Drawing2D
Public Class Form1
Inherits System.Windows.Forms.Form
Public hlb As Point 'not used
[Code] .....
I am using vb express 2010.
