Declaring A Variable Of Type Interface And Object
Oct 19, 2010what is the difference between declaring a variable in this way
ByVal
List As IEnumerable as
a parametre in a function
Dim
[Code]....
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.net - Invoking Interface Method Using System.Object Type Variable
Jan 6, 2011I have an interface ITest with a method GetResult(). I have a class Test which implements ITest and thereby defines private method GetResult().
Next I create an instance of Test in a different class. The code is as below:
Module NewClass
Public Sub New()
Dim i As ITest = New Test()
[Code]....
I am migrating existing code from VB 6 to VB.NET and hence I'm not supposed to change the access modifier of GetResult. Leaving it Private will throw InvalidCastException Unable to cast object of type 'System.Object' to type 'ITest'
Object type variable o is used in many places and hence I don't want to change that. And yes, Test implements ITest.GetMember with a different name.
.net - Declaring An Object Of A Conditional Type With A System.Type?
Sep 27, 2011I am attempting to launch a specific form depending on the selected node of a treeview on the doubleclick event. The code I need to use to launch the form is a little bulky becuase I have to ensure that the form is not disposed, and that the form is not already openbefore launching a new instance. I'd like to have all of this checking happen in one place at the end of the function, which means that I have to be able to pass the right form type to the code at the end. I'm trying to do this with a System.Type, but that doesn't seem to be working
View 1 RepliesDeclaring Object Variable - Inactive During Initialization Of Module?
Feb 16, 2012Got a question regarding declaring a variable. Basically I have a module that writes to a text file using textwriter which is declared for the whole module to use at the top of the code. But what I want to do is clear the contents of the text file when the program is executed (using file.writealltext). The problem I have is that the file is obviously already in use as a result of the textwriter and the file cannot be modified because of this.
My question is: is there any way of declaring the textWriter object later on (not during the initial initialization of the module) without passing the object between functions? Setting the variable as inactive or something along those lines during initialization would be ideal.
.net - Difference Between Declaring And Constructing A Value Type Object?
Oct 2, 2009I'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
[code]....
Cast Array In Object Variable To Type In System.Type Variable?
Apr 14, 2010I have this function:
Public Sub DoStuff(ByVal type as System.Type, ByVal value as Object)
End Sub
The 'value' argument is always an array of the same type as 'type'. How can I loop through the values of the array?
I'd like to be able to do something like this:
DoStuff(GetType(Integer), New Integer(){1,2,3})
Public Sub DoStuff(ByVal type as System.Type, ByVal value as Object)
//Strongly types arr as Integer()
[Code].....
Unable To Cast COM Object Of Type 'System.__ComObject' To Interface Type 'MSTSCLib.IMsTscNonScriptable?
Jun 1, 2012I am building a software which will be used to create a remote desktop connection. However I'm getting this error:
Unable to cast COM object of type 'System.__ComObject' to interface type 'MSTSCLib.IMsTscNonScriptable'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{C1E6743A-41C1-4A74-832A-0DD06C1C7A0E}' failed
due to the following error: Δεν υποστηρίζεται τέτοια διασύνδεση (Exception from HRESULT: 0x80004002 E_NOINTERFACE)).
[Code]...
Error : Unable To Cast The COM Object Of Type 'System._ComObject' To Interface Type 'Microsoft.Office.Interop.Word.CustomProperties'
May 10, 2009I have been trying to use vb2008 to automatically update CustomDocumentProperties fields that I have set up within a pro-forma document. I can load the Word application and word document without problems.I want to update the CustomDocumentProperties fields with data read from a dB. To do this I am assuming that I need to iterate through the CustomDocumentProperties fields within the word document and when one is "found" that matches the data I wish to merge then assign the dB value to the field.The problem is that I am getting an exception error when I try to reference the document customdocumentproperties
"Error : Unable to cast the COM object of type 'System._ComObject' to interface type 'Microsoft.Office.Interop.Word.CustomProperties'. ...... "
my code looks like;
Dim WordApp As Word._Application
Dim odoc As Word._Document
Dim BContinue As Boolean = True
[code].....
C# - Copy Object Of Type AA To An Empty Variable Of Type BB?
Feb 15, 2010Writing an asp.net mvc app and i have something like this...
Public Class AA
'... has some variables...
End Class
Public Class BB
[code]....
So, now in my program, i just want to copy object of type AA to an empty variable of type BB?it makes sense to do this, as i expect all the fields in AA type object to be copied to the newly created BB type object, and the ExtraVariable in the BB type object i would (will) just assign a value to it later (after the copy) on my own time!!I know copying BB type to AA type would not be appropriate as there would be lost data!But im trying to copy AA to BB, I've used both DirectCast and CType to do this, and i keep getting "unable to cast" error!
Note: I'm using vb.net (but can read c#, no problems)
Calling A Method Over Variable Of Type Object In Vb And C#
Jul 5, 2009in vb I can do that
sub SetFocusControl(byref ctl as object)
ctl.Focus
end sub
in c# the compiler complaint that object doesn't have a Focus method
void SetFocusControl(ref object ctl)
{
ctl.Focus();
}
how can I do the same in c#?
Operator '=' Is Not Defined ... For A Variable And Object Of THE SAME TYPE?
May 5, 2011Okay, I am TOTALLY confused here. I have a class... say MyClass. It has several properties of another class of my type, say MyHelperClass (along with other properties).
I am doing the following:
Dim inst As MyClass = New MyClass() With {
.p1 = sv1,
[code].....
Declaring Each And Every Variable
Apr 26, 2011Trying to declare some arrays. I haven't worked with them that I remember. I always took the long road, of declaring each and every variable, but would like to learn this method. The problem is I'm having trouble with the methods I'm finding on the net..[code]for some reason there is a squiggly under each MonsterName except in the declaration that says "declaration expected"
View 16 Replies.net - Declaring A Byte Variable?
May 30, 2012We can declare a byte variable like this, for hex '88'
Dim bytes = New Byte() { &H88 } My case, 88 is assigned to a variable, hexvalue
How to declare the byte with the variable hex value?
Dim bytes = New Byte() { &H & hexvalue }the above throws syntax error.
.net - Declaring A Variable As Byte
Feb 19, 2011I'm trying out a program which I found on the net. Why is it necessary to put to curly braces at the end of the statement? It gives an error: "Byte has no constructors". Dim data As Byte() = New Byte(1023) {} I can't put the code like this either, it produces the error "byte cannot be a 1-dimensional array".
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Declaring A String Variable?
Mar 29, 2012if this silly but I am trying to declare a string variable by the following line
[Code]...
Declaring A Variable For Form And Using It?
Feb 8, 2010I have declared this variable in a module : Public GenericForm As System.Windows.Forms.Form
and then through code I can asign to that variable a specific form .For example GenericForm = Form1. Then I can use that variable to handle that specific form , for example :
GenericForm.Show
My problem begins when I want to handle a control on that form , for example :
GenericForm.TextBox1.Text = "aaa"
This code creates an error reading :TextBox1 is not a member of System.Windows.Forms.Form.I have been using code like this in VB6 and was quite useful ,but now in VB .NET I cannot .You see I have many forms on which there are some text boxes with the same name,so I declare a generic variable as Form and accordingly insert the code the desired text box conform the form I wish each time . Can I do this in VB .NET too ?
Declaring Variable Dynamically In .net?
Dec 21, 2011I have started using the builder class to create my connection strings for the sole purpose of making more generic connectivity code. However, I am stumped on this issue. The MS eConnect product apparently expects to receive integrated security=SSPI in its connection string if you want to use integrated security, (vs Integrated Secturity=True). I thought I would just pass "Trusted_Connection"="SSPI" to the builder class.
as it turns out, the item for Integrated Security is boolean and despite what the documentation says, will not give me SSPI in my connection string. Has anybody else found this issue and is there a simple fix for it? as for now, I'll simply strip out the item and replace it in my string.
Declaring A Variable And Setting It Correctly?
Nov 4, 2010I'm having a problem declaring a variable and setting it correctly.
BEGIN WORKING CODE:
private sub doSomething
Dim tokenHandle As New IntPtr(0)
Dim dupeTokenHandle As New IntPtr(0)
[Code].....
Declaring A Variable Length Array?
Apr 26, 2010I am new to VB.NET but used to write a lot of code in VB 6.
How do i declare a variable length array in VB.NET?
In VB6, i would just put:
Dim sArrayList() As String
But when I do that in VB.NET, it highlights my array name and says "unused local variable". What do I need to do to get it to work without an error?
Declaring A Variable TableAdapter On A Form
Aug 15, 2011I am building a generic search form in my application. This will allow the user to search for various records throughout the application. The one thing I cannot seem to figure out is how to allow the declaration of the TableAdapter to change at run-time. Each part of the app will be passing a variable to the search form to specify which table should be loaded. In the form class I have the following:
FRIEND WITHEVENTS tbaSearchData AS database.databaseTableAdapters.TableOneTableAdapter This is great for TableOne. But, I have about a hundred tables that could be searched through. To load the data I'm using a DataGridView and populating it via a private method.
Declaring Class Variable As A Reference?
Apr 5, 2011I have a class that I would like to link at construction to a given control (say a textbox)
I know I can put a variable into a subroutine referentially but is there a way to store it in the same capacity?
VS 2008 - XML Xdocument - Declaring The Variable
Apr 18, 2010I've got
Option strict ON
Option explicit ON
How should I declare the variable:-
Dim bounds as? = (From item In xml...<bounds>
[Code]
.net - Getting An Advantage To USING Versus Declaring A Context Variable?
Nov 5, 2009These two snippets do the same thing - is there one that's better than the other, or is it just a matter of preference?
Using context As MyDatabaseDataContext = New MyDatabaseDataContext()
Dim test = context.Employees.Count
End Using
vs.
Dim context As MyDatabaseDataContext = New MyDatabaseDataContext()
Dim test = context.Employees.Count
Asp.net - Declaring A Global Request.ServerVariable Variable
Jul 7, 2011After many many years of using Classic ASP, I am attempting to delve into the world of ASP.Net using VB. I have gotten way to use to being able to declare variables on a page, inlclude that file and use it everywhere. I am struggling to declare a global variable. I just need
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Declaring Private Variable - Automate Properties?
Sep 28, 2009I come from C# (use VS 2005, .NET 2) and I know that when I declare a private variable I can "extract" from it the corresponding "property". In VB.NET I've declared a lot of properties (in the diagram class designer). Now am I forced manually adding the corresponding private fields?
View 4 RepliesDeclaring A Object - Instance Of An Object To Be Created When A Form Loads Or Another Class Is Created
Oct 5, 2009If you want a instance of an object to be created when a form loads or another class is created, you have two options:
Public class example
private IAmAObject As IAmAObject
public sub new()
[CODE]...
Or like this:
public class example
private IAmAObject as new IAmAObject
public sub new()
[CODE]...
I always use the first one. It's more type work but I think it's neater. How about you people and is there any real difference between the two?
How To Use A Class Without Declaring Object
Mar 30, 2011I'm trying to develop a class in VB .NET in order to manage a language globalization stored in a database and editable by the user.What I need is to know what kind of class I need to declare in order to use it without declaring a new object. For example, the way My.Settings is used.
One of the goals is that in some project the developer imports the reference and after that access directly to a property. For example: My.CustomLanguage.GetWord("Hello") without declaring objects.
Is this possible? And if it's what is the best way to aproach it?
Declaring Fixed Length Variable Arrays In Structure?
May 25, 2012How do I declare a fixed length variable arra
Structure MyInformation
<VBFixedString(4),System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.ByValTStr,SizeConst:=4)> Public ReturnStatus As String
[code]....
Interface And Graphics :: Link A Class / Object To An Interface?
Apr 21, 2010I'm trying to make a .dll that contains a lot of basic functionality that a program can use. Currently i am trying to use interfaces to make a lot of this functionallity independend of the program using it but i hit a snag. The Basic idea is that a programmer will create his own object using the interface discribed in my .DLL file. Then implements those functions as he likes. He can then instanciate a controller (found in the same DLL) and sends his custom object implementing the interface to that Controller. The controller can then be started and will take over all the work. I do not know what type of object is send to the controller and idealy i want to program it in such a fashion that i shouldn't care as long as the object send implements that interface.In code I am trying to achieve the following: (quite simplyfied)
.Dll:
Code:
Public Interface MyInterface '<----Decleration of the interfaceFunction GetData() As Integer
Function SetData(Data As Integer)
end interface
[code]....
this propperly. I know that the second i set the interface adaptor in the Controller VS comes nagging that it can not be converted to a "MyInterface" Class. Obviously i am doing something wrong. I can change the datatype that the controller expects to the "MyController" type but that would completely ruin the whole idea of flexibillity. I am hoping someone sees what i am trying to do and can point out where i made the thinking error.
Gained By Using The Function Itself To Hold The Return Value Instead Of Declaring A Local Variable?
Oct 28, 2010What's best practice (in VB.Net):
Function GetSomething() as String
GetSomething = "Here's your string"
End Function
or
Function GetSomething() as String
Dim returnString as String = "Here's your string"
Return returnString
End Function
Obviously, neither of these implementations make any sense, but they're just meant to illustrate my point. Is there anything to be gained by using GetSomething itself to store the return value instead of declaring returnString locally and then returning that (does it avoid having an extra string allocated/instantiated - and if so, are there any performance/memory benefits)?