Check If A Variable Is Equal To Some Values Or Not
May 15, 2011I want to check If a variable is equal to some values or not, for example:
if a = 1 or a = 5 or a = 7 or a = 10
is it possible to do it like sql:
if a in (1,5,7,10)
I want to check If a variable is equal to some values or not, for example:
if a = 1 or a = 5 or a = 7 or a = 10
is it possible to do it like sql:
if a in (1,5,7,10)
How does one check to see if the system time is equal or not equal to a specific time? So, say I want to perform an action if your system time is between 6pm and 6am. Or something similar?
View 1 RepliesInput a range of numbers and sort them into 6 equal amounts and then having the program tell you which amount the number was put into?
I.e
Input:
1200, 2400, 600, 600, 300, 300, 1200, 1200
Sorted into:
Group A: 2400 = 2400
Group B: 1200 + 1200 = 2400
Group C: 600 + 600 + 300 + 300 + 1200 = 2400
I'm trying to assign some parameters for a stored procedure with some values that are stored in a data table. in the code, I can set the parameter values to the data table, and give a column header or index without issue, but when it tries to execute at runtime it bombs out.the error I get is a variation on "Failed to Convert Parameter Value from a DataColumn to a String" depending on exactly how I try to assign the value.the data types are all correct elsewhere in the code.
my code for this bit is
Try
ConnectionAttempt.Open()
Try
With NewYearCommand_Dates
[code]....
other things I've tried to get this to work are all variations on the .Value=dates bit, such as
.Value=dates(0) (so using column index)
.Value=dates.columns(0) (again using column index)
I've also tried declaring variables, and setting their values to the values in the columns, but the code returns an error saying that "Value of type 'System.Data.DataColumn' cannot be converted to string".I should point out that i'm doing this for 3 tables at once in this sub, 2 of them will only have a single row of data, but the third has an indeterminate number of rows.I'm afraid I don't know what else to do. I'm lead to believe by my mate and my lecturer that this should work, and of course it will work, but the evidence says otherwise.
I've never really used the Check List Box in the past, however, for the recent program I am developing, I am using this control rather than individual check boxes scattered across the form.Anyway, I want to be able to program through code which items get checked in this checked list box. Specifically, I have a variable that contains the text of each check box that I want checked.With a normal check box, I can simply say:
Dim strNames As String
strNames = "John Doe, Mark Johnson, Mike Brown, Cindy Smith"
If strNames.ToString.Contains("Mike Brown") Then[code]....
How do I declare/define a ResourceManager in the following code so it doesn't equal Nothing when it reaches rm.GetString("Magnitude") in the following code? My.Settings.. is returning a valid string.
Imports Gigasoft.ProEssentials.Enums
Imports System.Resources
Imports System.Configuration
[code]....
I would like to compare dates (not times) for 2 datetime variables. I get one of the dates from database as follows and comapre it with yesterday.How can I do it?
[Code]...
How can i check a file's md5 if it's equal to one in a listbox?[code]...
View 3 RepliesIs there a statement to check if a does not equal b? or is it necessary to
vb
if a = b then
'blank
else
[code]....
I have been searching the internet trying to understand in its simplist form why this behavior happens.
Dim mysingle As Single = 456.11 Dim mybool As Boolean = mysingle = 456.11
In the lines above mybool becomes false. I found this behavior when putting the single into a double I found extra digits showing. The .net documentations states a single is an approimate value I gatehr a single is a 32bit floating point number? But why are extra digits appearing when I have explicitly said what the number is.. surely the memory should store that numbers either side of my number are 0 to fill up the memory location?
I have 10 checkboxes on my screen. I have a variable setup called "case" as a string. I want to know how I can say:
If checkbox1 is checked then case would be equal to "this".
If checkbox2 is checked then case would = "that"
Example of something I tried to cook up but didn't work because it tells me that I can't only use this in a "select case".
Dim Case as string
If checkbox1.checked = true
case = test1
end if
If checkbox2.checked = true
[Code] ......
i am using a c++ dll to control a usb device. a while back i created a vb6 program that interfaced with the dll.it worked perfectly.now i am trying to make one in vs2008.here is the header of the function i am trying to use in teh c++ dll [code]but this get no value for textbuffer.and after the function is called a few times it gives me a memory error. i think it is because the string is not fixed length.is there a way i can get this to work in vb.net without rewriting the dll
View 3 RepliesIm trying to use this code to check if files in a directory equal to the text typed in these textboxes. The files end with extension ".ldb". The code doesnt seem to work
View 11 RepliesHTML
Public Partial Class WebForm1
Inherits System.Web.UI.Page
Public num1 As Double[code]...
This is a part of a calculator code. When you press the button "BtnAdd" the text in TxtRes is held by the global variable "num1" and the operation number (whether add or subtract) by "oper". My problem is : OUTPUT 1: prints num1 = 25 (for example)While OUTPUT 2: prints num1=0
Why is this happening ? Isn't the value of num1 supposed to be equal everywhere in the form at a given moment ?
Why are static variables set equal to 0 in the declaration when 0 would be the default value of the numeric variable anyway when it's first declared? Not including the "=0" in the static declaration seems to work with no problem.
View 2 RepliesI have a form that I am adding a set of buttons to. I am adding an event to those buttons. I need this event to function slightly to determine what button was pressed.
I need the button to simply set a string variable equal to the clicked buttons text so I can determine what button was pressed.
How can this be accomplished?
''Adding the buttons''
For Each dr In dtMenus
Dim strMenuName As String
strMenuName = dr.Item("strMenuName").ToString
[CODE]...
i am using while loop. i need to check whether the previous line is equal to next line ...
Try
Dim r As Integer
r = str.IndexOf("action = LGN; description = Success")--- i need to check next line also same content[code].....
In the following LINQ query, i would like when the Loc=Locale.Gr all the records with GrID=100 returned and when the Loc is anything else all the other records with GrID <> 100 returned.How can i achieve this one? I tried something like the following, but it is totally wrong.
PrivateSub Test(Byval Loc as Locale)
Private Const GrID as integer = 100
Dim Query = From c In Mob Where c.CountryID = IIf(Loc = Locale.Gr, GrID, <> GrID) select c
End Sub
[Code]...
I have a problem with a sql query. Through the query I am trying to search database for any occurrences of string (can be anything) in a column using the SQL LIKE command. The problem is that it works fine for most of the strings say john, jim, ji"m , but does not work when i include the following characters which are ( ' , { , } , and a single quotation mark). MYSQL query takes care of these special cases by putting them in [] block whenever user enters them .But i am getting the following error when i go to query the database using the GetSelectCommand() in VB.NET
Exception Details: System.ApplicationException: Number of values provided must be equal to the number of placeholders in query.I have checked the query over and over again .. but its fine .My database server is Sql Server 2008.So my application throws the exception in this command:
Using reader As MustDisposeDataReader = _
pmSystem.DatabaseManager.GetSelectCommand(selectStatementBuilder.ToString(), New Object() {})
Where MustDisposeDataReader is an instance of a class in an internally developed library, which inherits from System.Object. pmSystem is an instance of the class PlanManagerSystem which implements the commandlayer. GetSelectCommand() takes the select command
This is my problem.I have a field set up in MS Access to Boolean YES/NO, this field is populated when the user check a checkbox on a windows form. If the user check a checkbox, the value is written as checked in the data field (MS Access).The problem is when I search for the user information, I need the information from the Data base to populate(return) to the windows form. Example: If I enter a users phone number and the user data is present, the form gets populated with the information the user previously entered which was store in the database.Example: If the user selected checkbox1 and submits the form. When I search for the user info, the check box should check(populate) because the user had checked it on submit.Here is what I have done:
[code]...
I am getting the check value correctly in the database using a Boolean.Here is one of the errors I am getting. Unable to cast object of type
'System.Boolean' to type 'System.Windows.Forms.CheckBox.I am having trouble putting the codes in a code tag or block
I tried this code to check if the data in textbox1 not equal to any data in column name, so insert the data that in the textboxes to the table1. Esle.. do another thing. But it didn't success with me.
Code:
Dim conn As New OleDbConnection()
conn.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;" _
& "Data Source =" & Application.StartupPath & "DataBaseName.mdb "
[Code].....
I have a Boolean that writes to a data field. The data field(column) is set to YES/NO, if the user check a checkbox, the value is written as check in the data field.The problem is when I search for the user information, I need to get to form to the state it was in when the user submitted it.
Example: If the use select checkbox1 and submits the form. When I search the form, I need to make that particular check box check.
[Code]...
[code]...
A first chance exception of type 'System.NullReferenceException' occurred in MyApp.exe
A first chance exception of type 'System.ComponentModel.Win32Exception' occurred in System.dll
1- How can I check the size of a variable? Size in bytes, not length. (;
2- What data can be stored into byte variables? And what the maxium size of the variable?
3- How do I store data inside a byte variable?
To check if a setting has been set, I currently use:
If My.Settings.Username <> "" Then If this the best way to check? Is there a better way?
I have got a question to you. I want to know how I can check the listview items in form1.listview1.items and me.listview1.items to see that if both listview have got the same text property of the items then display the messagebox that says "you can't add the same items again. Please select a different item and try again!", otherwise display the messagebox that says "the items have been added".
View 2 RepliesI am developing an application for multi user using vb.net with back end as ms-access. For the table name as employee_master, there is a column, name as student_profile having datatype as Yes/No .
[Code]...
This line of code references a checkbox in a Gridview, how can I assign the value of the check box 1 or -1, I think it is for checked or unchecked, to a variable so that I can run an if statement against it, and change it to True or False?
dt.Rows(row.DataItemIndex)("DisplayString") = (CType((row.Cells(3).Controls(0)), CheckBox)).Checked
I have a BaseClass, a DerivedClass1 and a DerivedClass2 from a third party library. DerivedClass1 and DerivedClass2 both inherit from BaseClass.There's a ContainerClass, from the same library, with a member variable ActiveItem, which can be of DerivedClass1 or DerivedClass2, so it is declared as BaseClass.I want to know if ActiveItem is of DerivedClass1, as it can change in runtime without notice.If I do
Dim isDerivedClass1 as boolean = TypeOf(oject.ActiveItem) Is DerivedClass1
then I get a compile time error, telling me that ActiveItem can never be of DerivedClass1 type.I have tried several combinations of GetType and TypeOf but it doesn't seem possible to check this. I have also tried to declare an auxiliary DerivedClass1 variable and comparing their types, but haven't got any luck either.
Edit:The following code doesn't compile in vs2005 SP1.
Public Class Base
Public x As Integer
End Class
Public Class Derived1
[code]....
In Visual Studio 2010 is it possible to check the state of variables during run time. When a run time error occurs the error is highlighted and you are able to mouse over different variables to see their values when the error happened. I would like to do something similar except without the error.
View 7 Replies