Difference Between "=" And "As" When Creating Object Variable?
Jun 23, 2009I wonder, is there any difference between these two line of code in perfomance (suppose we have class called Car)?
Dim c = New Car
Dim c As New Car
I wonder, is there any difference between these two line of code in perfomance (suppose we have class called Car)?
Dim c = New Car
Dim c As New Car
When we can access the public methods via object then why is there need of inheritance.
View 2 RepliesI`m a beginning programmer, and I`m trying to build my first 100% object. The object would be a USER object, representing rekords from users table in database. The table in the database has 5 columns ->
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what's the difference between variable array and object array?
View 7 RepliesI am converting C# to VB right now
in VB, I have these codes :
Dim ind As Foo.Index
Dim ed As Foo.Edit
ind = New Foo.Index
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Seems I do need to show all the codes. But I need to talk directly to you as well (or You just install the software of mine).
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"))
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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.
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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.
Is there any difference between the 2 methods below for calculating c ... specifically boxing/unboxing issues?
Dim a As Integer? = 10
Dim b As Integer? = Nothing
Dim c As Integer
' Method 1
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If I create a class in VB called Test,I noticed I can instantiate it like:
Dim test As New Test
or
Dim test As New Test()
What is the difference?
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:
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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
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Been getting this error with my program. Using framework 2.0
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I'm trying to enter automatically todays date in a number of records in the Table 'Applications' into the field 'Date_refund_request'.
However it is giving me the error 'object variable or withblock variable not set' in the line "Set rs = db.OpenRecordset(strSQL, dbOpenDynaset)".
The code is as follows:
Private Sub Command16_Click()
On Error GoTo Err_Command16_Click
Dim db As DAO.Database
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I am trying to use this block of code to save attachemnts from Outlook into a folder on my harddrive.
VB
Imports Microsoft.Office.Interop
''' <summary>
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Do List's hold the instances of a variable element or just the pointer to the the variable element? My application uses a list of elements, which can be re-ordered at any time, but I need to maintain another list of pointers to those elements, so that the element pointers can be used to access any element irrespective of their order in the main list? the difference between a pointer or a variable in the contect of list elements?
View 16 RepliesI want to know the difference. I have given 2 lines code.
CODE:
Let me know difference between both datatype.
I'm trying to create a pivot table by opening an Excel file from my drive.But I'm receiving the error saying "Object reference not set to an instance of an object".[code]
View 1 RepliesI'm having this problem with my code and cannot seem to get past it although it was working fine before. The error is "An error occurred creating the form. See Exception.InnerException for details. The error is: Object reference not set to an instance of an object." The code is:
CODE:
I am trying to get information to be pulled out of a database and show in text boxes on another form (frmviewsdets). The error occurs when it gets to the line frmviewsdets.txtsnumber.Text = rdr("StudentNumber") and even when a breakpoint is applied there it just moves on to the next and so on.
I have tried to show frmviewsdets before I pull the data out of the database beut I get the same message.
In the Session_Start of the Global.asax i have
Sub Session_Start(ByVal sender As Object, ByVal e As EventArgs)
Session("login") = False
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Why i am getting error the error Object reference not set to an instance of an object. at line
If Current.Session("login") Is Nothing Then
while checking for the login state as follows?
If GetLogin = False Then
'Do something
End if
I mean i have already created the instance on the Session_Start... Haven't i?
Dim MyOrders As Order()
Dim MyOrders2() As Order
I'm using vb10. I need to use a timer for forms to turn off and on and I was going to use a timer control and I noticed there is a timer class. What is the difference? Should I use the timer class instead?
View 5 Repliesif I created a new object like this Dim sqlconn As New SqlClient.SqlConnection(cs)
and Dim sqlconn = New SqlClient.SqlConnection(cs) Whats the difference?
I'm writing in ASP.NET 4 / VB.NET. I am querying an MSSQL database and sometimes have records come back with no results...so I enclosed the call I was making upon the results in an If..Else clause to set a default value if the database comes back with no results...but now I am getting this "Object variable or With block variable not set error". Here is the relevant code:
Dim clcfirst
Dim rhcfirst
Dim clcdate As Date
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I am populating combo box from database. In debug i can see that the combo box has been populated . here is the code
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dim myCollection as new Specialized.StringCollection
dim myFoundThings as new ArrayList
dim index as Integer
dim newResultMemberName as String
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This is part of some code that will run without user interaction once it's spinning away, and I need to create a unique object from some items found in a StringCollection, naming the objects using information found in the strings stored in that StringCollection.
I've been working in .NET for some time now, but occasionally I still get confused by a disparity between the framework and my prior experience in C++.In .NET, all objects are either value types or reference types. Reference types are allocated on the heap while value types are allocated on the stack (in the current CLR implementation, anyway). I get that. However, at least in VB.NET, you can still define a constructor on a value type.
Public Structure Coordinates
Public x As Integer
Public y As Integer
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In VB.Net is there any difference between the following three ways of initializing object variables
Method 1
Dim commandObject As SqlCommand
commandObject = New SqlCommand("MadeUpCommand")
Method 2
Dim commandObject As SqlCommand = New SqlCommand("MadeUpCommand")
Method 3
Dim commandObject As New SqlCommand("MadeUpCommand")
Is one more efficient than the others, or are they effectively all the same?
I am having some trouble creating an object array of different object types. Here is what I have so far:
Public Sub New()
Dim b1 As New Book("Book Title 1", "Gold Book Publisher", 1.0, "Bob Jones", "192DJDJD212", "01/02/10")
Dim b2 As New Book("Book Title 2", "Gold Book Publisher", 1.0, "Bob Jones", "192DJDJD212", "01/02/10")
Dim b3 As New Book("Book Title 3", "Gold Book Publisher", 1.0, "Bob Jones", "192DJDJD212", "01/02/10")
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If I define the array As Book (Public publicationArray(6) As Book) or Magazine (Public publicationArray(6) As Magazine) I am able to access the properties of that class but not both. I think I need to define a type for each array instance but not sure how to do this.
if you are debugging or releasing a projet , vs writes exe or bin files to the bin and obj folder in a release and debug version, are ther differences bewteen these files with the same name in 4 folders ?, eg myproject.exe
View 3 RepliesThe code below works for the class that I hard coded "XCCustomers" in my RetrieveIDandName method where I use CType. However, I would like to be able to pass in various classes and property names to get the integer and string LIST returned. For example, in my code below, I would like to also pass in "XCEmployees" to my RetrieveIDandName method. I feel so close... I was hoping someone knew how to use CType where I can pass in the class name as a string variable.
Note, all the other examples I have seen and tried fail because we are using Option Strict On which disallows late binding. That is why I need to use CType.I also studied the "Activator.CreateInstance" code examples to try to get the class reference instance by string name but I was unable to get CType to work with that.When I use obj.GetType.Name or obj.GetType.FullName in place of the "XCCustomers" in CType(obj, XCCustomers)(i)I get the error "Type 'obj.GetType.Name' is not defined" or "Type 'obj.GetType.FullName' is not defined"
'+++++++++++++++++++++++++++++++
Imports DataLaasXC.Business
Imports DataLaasXC.Utilities
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