I have a class in vb.net defined as public class A
class A is created on Load and gets called once per program loop
The constructor for class A includes the argument (byref Value as long)
I have a global variable called varB that is passed to class A on creation.
now why when varB is altered during the program loop, the change is not reflected within the class?
I have some classes, BsfciFile and StudyFlashCard. Bsfci is the extension to which I save my set of flashcards in an INI format. I am currently working to transform my code from using Windows API calls to access the INI to using a IniFile class that I found on the internet. I would like the BsfciFile to have a Array of StudyFlashCard objects, but I would like the StudyFlashCard class to use the IniFile class object contained in the BsfciFile class. I can pass the IniFile from the BsfciFile class to the constructor for the StudyFlashCard class, but I want it to modify the same IniFile as the BsfciFile class has later on.
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Hi
I've got a pretty general question about the best practice in passing an object reference to a Form in VB.NET. My form is a dialog and I've created an overload ShowDialog method, where I pass an Object into it ByRef.
The trouble is, I want to be able to refer to that Object throughout my dialog Class and not just in the ShowDialog method. For instance, some of my Events for controls on the form, need to reference that object.
I know I could create a local Private variable in the Class and assign it to the passed value, and then use that value. However I'm thinking this isn't very efficient because it would (I believe) create a new copy of the Object (which is a complex, large class in itself).
How can I get the name of the object that was passed byref into a method?
Example:
Dim myobject as object
sub mymethod(byref o as object)
debug.print(o.[RealName!!!!])
end sub
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I'm using this for logging. I use one method multiple times and it would be nice to log the name of the variable that I passed to it. Since I'm passing it byref, I should be able to get this name, right?This would give you the parameter name in the method and it's type, but not the name of the variable that was passed byref.
using system.reflection
Dim mb As MethodBase = MethodInfo.GetCurrentMethod()
For Each pi As ParameterInfo In mb.GetParameters()
[code]....
If you put that in "mymethod" above you'd get "o" and "Object".
I have code, shown below, that works all except for 1 thing: The variables being passed byRef get passed, but once modified in the else section of the "if me.invokerequired" code of RecordData, the variables are never updated in the calling function. To reiterate, the calling function does not receive the updated data that is in the variables custid and amt.When debugging, I see the data change in the else section of "if me.invokerequired", but once it returns from the callback the data is missing.[code]
View 15 RepliesVS 2008 VB/I've implemented an interface to a .com program written in c++. I'm trying to access a data structure array(uNewValues) of type PLCCOMMLib.ANALOG_CONTIN. uNewValues should be a datastructure array of several elements (iSigIDCount). My problem is I only get the first array element of the datastructure.I've tried several methods and looked into marshalling but don't understand how to implement marshalling if that is the correct option.
Code below:
Public Sub AnalogContinUpdate(ByVal iSigIDCount
As Integer,
ByRef puTimeDateStampGMT As PLCCOMMLib._FILETIME,
ByRef uNewValues As PLCCOMMLib.ANALOG_CONTIN)
[code]....
Is there a Limit to the parameters that can be passed byVal or byRef to a function or procedure in vb .net ?
[URL]
I have a subroutine that passes several variables to the called subroutine.I want one of the variables to be updated by the called subroutine and then check for the change in the calling subroutine. My code works fine except that the variable I am checking
calling Sub routine
Code:
Public Sub ProjectName_Exit(Cancel As Integer)
[code].....
I'm making a IM LAN Chat, and I don't want to limit it to a specific number of chats that can be open at any given time (By re-producing the forms and setting variables once a chat is open).
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This is the code:
Public Class userDefClass
private b as integer = 1
End class
Public Class Form1
private SomeClass as new userDefClass
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) [Code]...
I define some global variables of a class as follows:
Private Class MyClass
Private var1 as Decimal
Private list1 as List(Of string)[code].....
But I found that after this form is closed, all above variables, var1, list1, list2 still exist in memory. I thought they should be collected by gc since the form is already disposed as I confirmed.
Add: I have monitored half an hour after the form is closed. But these variables are not collected by gc. I have an automatic update procedure on the form which uses above variables.Since the above variables still hold values, the automatic update procedure is always called which causes exception. (One quick fix is to check if form.isDisposed in update procedure. But I do not think this is elegeant. Besides, these variables occupy memory.)
I'm new in .NET programming.I have a class Form1 that includes Button1_Click event.Button1_Click creates a multiple Text Boxies at run time)Here is the class:
Public Class Form1
Dim shiftDown As Integer
Dim counter As Integer
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I have a WCF Service exposing a single contract and operation:
<ServiceContract(Namespace:="ImageSystem")> _
Public Interface IUploadService
<OperationContract()> _
[Code].....
This subsequently leads to stream casting issues, because the generated function allows me to pass a memory stream as an input (which works correctly when passed through to the service), but instead of passing me back a new stream for the response, it attempts to cast the MessageBodyStream received from the service into my memory stream.
This is, in some ways similar to other posts but as you can see, there are no enums involved in my contracts - presence of Enums caused strange proxy class generation is marked as the answer in the similar post.
Is there anywhere I configure the proxy behaviour to use the contracts I've specified? Clearly I'm within a dev/test environment currently, but when this eventually goes to production it will be memory and file streams passed to the service, and the returned stream can be in any format to be honest, I intend to treat it as the abstract stream class. The only way round this I can see right now is to change my in stream to be the same as the anticipated out stream, but surely there is a better way?
I have a method with a custom attribute that lists other methods in the same class that it can call. I'm passing the called method to another class function that will read the attribute and pick one of the methods named in the attribute and return it's delegate. I'm having a hard time figuring out how to do this with reflection or event if it is possible.
<AttributeUsage(AttributeTargets.Method, allowmultiple:=False)>
Public Class ExecuteSimiliar
Inherits System.Attribute
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I have an issue with a data base updating it won't update for me in debgging mode it is stopping here on this bit of code which is highlighted in red. the error which comes up is .(update requires a valid update command when passed datarow collection with modified rows.)
Public Sub UpdateDataSource(ByVal ChangedRows As database.dataset1)
Try
'The data source only needs to be updated if there are changes pending.
If (Not (ChangedRows) Is Nothing) Then
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I would like to catch any exceptions from any method in a class so that I may record class specific data to the exception for logging before it is passed up the stack. I know that I can put a try-catch in every method of the class, but there are many methods and It seems there should be a more efficient way. Example of what I am currently doing:
public class ClassA
{
private int x;
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I want to pass a List of T where T is an object I've created that has about ten properties (strings, dates and integers).The lst passes to the function successfully. I am also passing an New T of the Object (itm as T).I can see all the values (see image below), but because it's generic I cannot seem to retrieve the property values and I cannot figure out how to iterate through the properties of each itm as they are retrieved in the For Each.[code]
View 10 Replieswith the code:
T02FldDct01("DPF01") = "ABC"
T02FldDct01("DPF02") = "DEF"
T02Database01.Open()[code].....
I am getting the following error at the ExecuteNonQuery() line: "Parameterized query 'Update Table01 Set T02=@DPV01,T03=@DPV02 Where T01=@T02Ctr'
expects a parameter value which was not supplied. Parameter name: @DPV01"
T02 is a nvarchar field.The Dictionary was defined and populated as follows:
Dim T02FldDct01 As New Dictionary(Of String, String)
T0201 = "01"
T0202 = "02"[code]....
why the update routine will not recognize this Dictionary variable?
I have created a structure with some variables that I'm trying to update during the course of a sub routine but they are not updating, when I cycle though them at the end all the variables are still set to 0.
Imports System.Data
Imports System.Collections
Structure Team
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I am trying to populate some fields in Word document using DocVariable:[code]The proplem that I am facing is when I open the document after running the program the fields won't be updated, so I have to go each field and highlight it then > right click > update field to get the new value!I need a way to update them or my work will be meaningless.I forgot to say that the DocVariables are inside textboxes.
View 1 RepliesI'm not sure exactly how to describe this. In VB6, there was a Timer command. I could create a variable of type Timer and loop until the current value for Timer exceeded the initial plus a given amount of time. This allowed me to update form variables while the timing loop was executing. How can I do something similar in .NET?
Here is a sample of the VB6 code:
Code:
Dim StartTimer As Double
StartTimer = Timer
Do
[code]....
I have a Public Sub I am using to enumerate running processes and then display them in a ListView.I want to be able to update the list automatically each second. I've thought of doing this in two different ways, but the method that I want to use is checking if the process has exited or not.
When reading up on the Process Properties, I ran into .HasExited and .Refresh.I thought that I could use a timer and have it tick at 1 second intervals. I would then check, each second, if the Process has exited. If it has, remove it from the list.The problem with this, is that I don't want to put the sub in the timer because it would just constantly flicker the control. I need to figure out a way to access the variables inside of the Sub while inside of the Timer's .Tick event.The other issue is being able to add processes that aren't there. Which I can within another sub. I was thinking I could create a sub that grabbed the Processes by ID, compare them to the list, and them add them if they aren't there. If I did this, I could also remove Processes by ID that aren't in the list.
I am completly flummoxed!!! I have writen code for updating my table from a form but when I use the same code only changing the table names it wont work I get the following message: "Update requires a valid Update Command when passed DataRow collection with modified rows" My codes are as follows:
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I am trying to add shared members in derived classes and use that values in base classes...
I have base
class DBLayer
public shared function GetDetail(byval UIN as integer)
dim StrSql = string.format("select * from {0} where uin = {1}", tablename, uin)
end function
end class
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currently there is error using the tablename variable of derived class in base class but i want to use it i dun know other techniques if other solutions are better then u can post it or u can say how can i make it work? confused...
I have some variables in my main Form, but I want them in all my other forms, how can I make them kinda global or something?
View 1 RepliesWhat's the proper way to declare variables in a class? I've been doing something like:
'in a class
public shared teststring As String = "first"
'on a code behind
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with shared variables loading a second window or reloading the page (without clicking the button) renders the hello world string. so how do I declare variables in a class but make it per instance?
Background: I am working on an ASP.net project that basically fills out a form from user input. The generated form (for reasons which I have no control over) must be a JPEG or TIFF. So the user fills out the web form, which takes all of the input values and meges them into a blank image (jpeg) of the form. Using System.Drawing, it merges all of the text onto the form at designated Points. The points are defined as variables which are modified at runtime to compensate for the resolution of the image (in case it get modified/re-generated at a different dpi). All of this is working fine.
Problem: Currently I have a Sub that determines the dpi of the master image, then adjusts the Points accordingly. However, there are ~50 variables that have to be adjusted. So currently I have the Sub go thru each point variable and manually adjust the X & Y values. I have been working on a Sub that will iterate thru all of the Point variables and do adjustment. Here's a functional sample of what I have working:Imports System.Drawing
Partial Class test Inherits System.Web.UI.Page
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This works...sort of. It allows me to grab each variable and modify it, but only in the instance. The original variable in the class is unchanged. Which means that when the program gets to the point where it's drawing text to the image, the points are unmodified. my basic question is: Is it possible to modify the original variable using this sort of process? If not, is the best way to use these modified values to declare the new class instance at a global level, then have the Sub that draws the text use the instance versions of the variables?
I realize that I could define all of the points in an array which would be easy to loop thru and update, but I've named each point variable something meaningful to correspond to the related text to be drawn.
I have created a new class with a string property called "Text".
The property will hold a sentence typed by the user.
I use "KeyPress" event to get the character pressed and use "Console.Text = Console.Text & e.KeyChar" to update the property. Where console is an instance of the class.
The problem is when I press "Delete" nothing happen.
That's the code within the event scope
MsgBox(Asc(e.KeyChar))
Console.Text = Console.Text & e.KeyChar
MsgBox(Console.Text)
I'm trying to create a generic Controller Class for generic events. But these these events still need to access their class variable. So my idea is to create the Base Controller Class with a ModelBaseclass variable as _ClassVar, which is inherited by all of the other class Controller classes will derive from. But I want the derived controller classes to override the _ClassVar with whichever one they need.
I want to do this, so the ControllerBaseClass can have all the generic functions that all the Derived Classes would use.
Model :
Public Class ModelBaseClass
Public Overridable Function Foo() As String
Return "Name"
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I am making a small application in which i have added a class module and a window forms in vb.net. i want to acess the shared variables and mathods of class without making any object.
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