Check Value Of Variable?

Jan 8, 2009

[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

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Check The Size Of A Variable?

Jun 2, 2011

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?

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Check When Variable Has Content?

Mar 3, 2009

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?

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How To Check For Listview Variable

Jan 8, 2011

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".

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How To Check Value Of Boolean Variable

Nov 15, 2011

I 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]...

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Assigning Gridview Check Box To A Variable?

Aug 7, 2011

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

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Check If A Variable Is Equal To Some Values Or Not

May 15, 2011

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)

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Check The Final Type Of A Variable?

Sep 6, 2010

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]....

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Check Variable State During Runtime?

Jan 15, 2011

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.

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Check When Value In A Struct Variable Is In A Dictionary?

Nov 8, 2011

I have a struct setup like the following[code]...

I then loop through a counter and add each PersonInfo object to the Dictionary. The Primary defaults to false if the Code is already in the Dictionary, but if it has not been inserted into the Dictionary, I want to set the Primary to True. It would be easy to check if the Code was the key, but I can't because the Code is not unique.

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Check When Variable Is Declared In A Page?

Nov 18, 2011

I have some web pages that include other pages, and I need to check if a variable (a string) has been declared in the page or not.

I was exploring try catch and finally, but im always getting a compiler error saying the variable doesnt exits.[code]...

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How To Check If Given Variable Is Defined With Attribute

Jul 16, 2009

I'd like to know if my textBox1 variable has the ABCAttribute. How can I check this?

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Check If Variable Holds An Instance Of Class?

Apr 10, 2011

Dim myObject As Something There I defined my variable myObject of type Something. But, as you can see, I am giving it no value yet. Sometime on runtime I want to check if myObject is holding a value or not. I tried this: If myObject <> Nothing Then But apparently I can't do such comparison.

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How To Check If Variable Is String Or Double Type

Jun 16, 2009

I want to see if a variable's type is string or double type. How to do it in vb.net immediate window?

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Checking Multiple Items In A Check List Box By Variable Values?

Oct 31, 2011

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]....

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Select Case To Check If A Variable Contains " The "?

Feb 3, 2011

I am trying to do a select case to see if a variable contains a list of the most common words in the English language.[CODE]....

Right now I get the hateful blue squiggly under b.contains with a message that overload resolution failed because no accessible 'contains' accepts this number of arguments. Any suggestions? Also this is my fourth thread is it better to make new threads as new questions come up or just role from one topic to the next during a project in one thread? I just don't want to make anyone mad for starting too many threads.

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VS 2008 Error: Range Variable 'sender' Hides A Variable In An Enclosing Block Or A Range Variable Previously Defined In The Query Expression

Mar 25, 2010

I am getting the error:"Range variable 'sender' hides a variable in an enclosing block or a range variable previously defined in the query expression."for this

Imports System.Data.SqlClient
Imports System.Linq
Public Class Form1

[code]....

I can select any other item from the table without the error. "sender" has the same properties as "receiver" in the SQL table.

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Variable Error "Variable 'reader' Hides A Variable In An Enclosing Block"

Aug 23, 2011

I receive the error -

[Code]...

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Program Function - Says, "The Type For Variable [variable] Will Not Be Inferred Because It Is Bound To A Field

May 18, 2012

Public Class Form1
Dim x, c, number(0 To 19) As Integer
Dim s As Integer

[CODE]...

The variables in the brackets [example] do not actually have brackets in them in the original code. These are where the issues are. For both variables, it says, "The type for variable [variable] will not be inferred because it is bound to a field in an enclosing scope. Either change the name of [variable], or use the fully qualified name (for example, 'Me.[variable]' or 'MyBase.[variable]')." Now, I'm not entirely sure if this is a stupid question or not, as I'm used to VB '98 because that's what we use in my programming class at High School. let me know why this won't work.

-Note: The intention of this program is to continually loop the generation of numbers for this list until I tell it to stop. Button1 ends the program, Button2 generates the list one time only, Button3 is supposed to loop the generation of the list, and Button4 is supposed to end the loop, but not the program.

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VS 2010 Compiler Creates New Variable Automatically When Use If Statement Without Strictly Declared Variable?

Jan 10, 2011

Say 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?

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Variable Naming Conventions To Illustrate Variable Type And Where Variables Are Declared

Aug 24, 2009

I am looking for a good resource on variable naming conventions to illustrate variable type and where variables are declared. So I will have public variables, Private variables, private or local variables. I also may want to declare variables with the same name in different class code (i.e. in the code behind different forms). I am assuming good coding would dicatate a prefix for declaration location.

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Import Text File : Object Variable Or With Block Variable Not Set

Mar 28, 2011

i have this error in the line of with xl.active......Object variable or With block variable not set.

Dim xl As Object
xl = CreateObject("Excel.Application")
With xl.ActiveSheet.QueryTables.Add(Connection:= _
"TEXT;C:Documents and SettingsUserDesktop429MEDICA2.TXT", _ Destination:=xl.Range("$A$1"))

[code]....

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Object Variable Or With Block Variable Not Set - From Property Get With Bindingsource.current?

May 31, 2012

Now I have the need to get a current value from a bindingsource in a property of a user control.In a previous thread I had tracked down the "Object variable or With block variable not set" to the return in the Get block of a property. At the time I was only using the Set so I just commented out the offending code until I needed it.

[Code]...

The error does not occur during a system compile, only upon saving the container object of the user control. As I said the Set works correctly, only the Get causes the error.I would like to know what I am missing/misunderstanding and am open to other suggestions of handling retrieving the current value of a bindingsource in a user control.

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Pass A Variable To Another Form Or Else Make The Variable Visible To Both Forms?

Sep 5, 2010

Using Visual Basic 2008 Express. I need to pass a variable to another form. Or else make the variable visible to both forms.

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Serialport VB2008.net - Input Variable And Output Variable Of This Terminal?

May 14, 2010

I am using vb2008.net express,I test vs2005term it work, can any tell me what is the input variable and output variable of this terminal?how to catch the input and output variable to a textbox1 for sending and a textbox2 for receiving when I press send button? is that possible?

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Write A Variable To A File That Has A Different Type Than The Function Assigned To The Variable

Sep 17, 2011

I have the following code that I am using to parse out a test file. I am getting variable conversion error in Sub Main() when I assign file = Read(). The return value of Read() is a TextFieldParser type. How do I assign the proper variable type to "file" so I can write the output to a text file?

Function Read()
Using MyReader As New FileIO.TextFieldParser("C:UsersColinDesktopParse_Me.txt")
Dim currentRow As String

[Code].....

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"Variable 'cnn' Hides A Variable In An Enclosing Block?

Mar 19, 2009

I have the following code but I get blue squiggly line in cnn and when i point my mouse pointer on it i see this message "Variable 'cnn' hides a variable in an enclosing block"

Private Sub BtnLockUnlock_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnLockUnlock.Click
Dim IsLocked As Boolean = FpSpread1.ActiveSheet.DefaultStyle.Locked

[code].....

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.net - Variable 'cl' Is Passed By Reference Before It Has Been Assigned A Value For DataView Variable?

Feb 1, 2012

I have the following code passing a dataView variable to a function and I am getting the following warning:"Variable 'cl' is passed by reference before it has been assigned a value. A null reference exception could result at runtime."

Function Editclass()
Dim cl As DataView
Bindclass (SqlConnection2, cl)

[code].....

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Class Inheritance Object Variable Or With Block Variable Not Set?

Sep 26, 2011

i had a class called Tag with a structure like:

public class Tag
private _members
public properties
public shared database_methods
end class

this class was tailored for mysql database. i'm currently adding access 2007 support so i split tag into tag and tagdata with structures like:

[Code]...

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Code Generation ... Object Variable Or With Block Variable Not Set?

Apr 25, 2012

I'm having trouble tracking down what is wrong and causing the above error. This only occurs when saving the design view in VS 2012. The code builds and runs fine.Full error text:Code generation for property 'CompanyValue' failed. Error was: 'Property accessor 'CompanyValue' on object 'ContactViewUC1' threw the following exception: 'Object variable or With block variable not set."

CompanyValue definition in ContactViewUC:
Public Property CompanyValue
Get

[code].....

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