Why Values Are Doubling When Use Structures
Oct 7, 2009I have my public structure in a separate module:
Imports System
Public Structure BezierSpline
Public PointsCount As Integer
[Code]....
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[VS2005] SafeArrayTypeMismatchException - Passing Two Structures Arrays And Other Single Values
Sep 29, 2008I have written a ActiveX DLL in VB 6 which is like -
[Code]...
When I do this everything works fine and I am able to pass value to dll. I am passing two structures arrays and other single values like int and double etc. So far so good. But when I insert this code in another application (created in same vb.net 2005) where I actually intent it to use then i get the following error -
System.Runtime.InteropServices.SafeArrayTypeMismatchException
Specified array was not of the expected type.
I am puzzled as to why is this happening. I checked basic settings and they are same. In short the code works if i create a new project and go on but does not work and gives error if I insert in an existing application's code where i wanna use. To test I created a dll without passing structure arrays and then it worked in that application.
[Code]...
.net - Crystal Doubling Up On T's
Jun 23, 2010I've written a vb.net application to populate a Crystal report and output it to PDF. The problem is that every text box in which I have the letter "t" is being printed out to the PDF as "tt". eg, instead of "customer", it prints "custtomer". The design time layout is perfect. And this only happens with text boxes on the report; value fields that contain the t character print out correctly.
View 2 RepliesAvoid Doubling In Combobox?
Aug 10, 2010I have following code that is generating random no. between 1 to 10. This is working fine. But, I do not want doubling in combobox (cmbRnd is my combo box). How can I avoid it?
Private Sub cmdRnd_Click(ByVal sender As Object, ByVal e As EventArgs) Handles cmdRnd.Click
Dim random As New Random(), i As Integer = 1
[Code]....
(2005) Arrays Of Structures Within Structures?
Jan 20, 2009I have a structure called 'Scheme' and in my program I want (ideally) an ArrayList of 'Schemes' (so i can add, remove schemes etc.). However, within the 'Scheme' structure, I want to have an ArrayList of 'Item''Item' is another structure. Are there any solutions out there for iterating through these arrays quite easily?
How can I easily add multiple Items to a Scheme and mutliple Schemes to my Scheme array. Code is below. When I try to add Items to a Scheme, I get the 'Object not set to a reference of an object, try the 'New' keyword', but you cannot declare 'New' keywork within a structure.
[Code]...
Doubling Image With Edge Detection?
Mar 16, 2011I have a function to do edge detection that works fairly good with one pass and without using a convolution filter. The only thing is that it will shift by one pixel the resulting image when I runt it from top to bottom and from left to right. I can live with that. Just a curious thing that I got when I ran it several times in a loop to see the effect of applying it several times on the resulting image.A deformed image appears at the beggining and then, bit by bit it splits appart and after shifting it the width of the original image I get a double image. I wonder how the computer keeps track of the first image and is able to separate the two after several iteractions.I know that in electronics you can have several signals in a circuit and you can separate them with frequency filters, or you can simultaneously download several files with the same modem aand the two computers will synchronize each one, but this surprissed me.
Here is a simplified version of my function
Private Function Preview(ByVal Thumb As Image) As Image
Dim bm As New Bitmap(Thumb)
Dim X As Integer
Dim Y As Integer
[code]....
I have tried with more complicated images and with larger sizes, but to make upload smaller I includes these two images of simpler and smaller size. A view of the GUI and an animation of the process:reload to see the animation.
Keyboard Event Doubling Events?
Oct 15, 2010Private Sub Form1_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles Me.KeyDown If e.Modifiers = Keys.Control AndAlso e.KeyCode = Keys.A Then
[Code]...
And whenever I click control-b (on keyboard) it inserts the bold tag twice.why does it do that? i use to have that code in a button, and the keyboard event would lead to button1.performclick but now when putting the button code in the keyboard it adds the tags twice
Structures And Arrays Of Structures?
Jun 2, 2010I read in the Book "Mastering Microsoft Visual Basic 2008" about "User-Defined data types".The example given is creating a Structure as follows.I wanted to check that so I wrote all the code given; I used a TextBox and a Button for this.(I didn't include the "CheckDate" here; that is in the book)
Structure CheckRecord
Dim CheckNumber As Integer
[code]....
The problem is this does work.What I get is "00000". and I found out that the "Checks(4)" Array does hold any value ie: on keeping the cursor over that, it shows "CheckAmount 0.0, CheckNumber 0 , CheckPaidTo Nothing ".
Create A List Of Structures Within A List Of Structures?
Jul 20, 2009I'm attempting to create a list of structures that contains a list of structures. I can't seem to figure out how to properly allocate the object for the inner list of structures. I expect the outer list of structures to have a couple thousand entries and the inner list of structures to be fairly small at 2 to 10. Both lists will grow over time but the number of elements within the inner list will be constant for an instance of the outer list. Meaning, if an instance of the outer list has 2000 entries each of those will have the same number of elements on the inner list, say 4 entries.
Here is a simplified code fragment. This fragment makes no attempt to create the instance of the inner list "StructBlist" since I can't figure out where to put it. Tried "New List(Of StructB)" in the declaration as well as "Alist(0).StructBlist = New List(Of StructB)" but neither works.
Public Class Form1
Structure StructA
Dim FieldA1 As Integer
[Code]....
Different Between These 2 Structures?
Mar 28, 2010What is the different between these 2 structures?
Structure INPUT
Public dwType As InputType
Public mi As MOUSEINPUT
Public ki As KEYBDINPUT
End Structure
[Code]...
2 Structures Using Eachother?
May 14, 2011Structure TextureStruct
Dim unk1 As ULong 'always 0x70007
Dim unk2 As ULong 'always 0x70007
Dim unk3 As ULong 'always 0x70007
Dim unk4 As ULong 'always 0x70007
Dim unk5 As ULong 'always 0x70007
Dim unk6 As ULong 'always 0x70007
[Code]...
Get A List Of Structures?
Jun 5, 2010Is it possible to declare a new list inside a structure.
I'm trying to get a list of structures that each contain a list of points,
but when i try to declare a new list inside the structure VB says "keyword not valid as an identifier"
Using Arrays In/with Structures?
May 24, 2009I'm currently doing this project where i have to create a program that let's the administrator manage students (and their tests.) I have decided to use Random Access file in this project.because structures will need fixed lengths...i don't know how will i search through the students (a function of the program) when each student structure has a different length because of the number of tests they've done.* I have created a variable in the aStudent structure so that i can know the number of tests a student has done...but don't know how to use it.
Public Class FormAdmin
Dim currentStudentName As String
Dim currentStudentID As Integer = 0
[code]....
Using Arrays With Structures?
Jun 18, 2011I have created a structure as below. I want the structure to be an array...so I can use a call like picks(1).a or picks.a(1) = blah blah. I don't understand how to use an array of a structure..
Public Structure apicks
Dim a As String
Dim b As String
End Structure
Using The Nested Structures
Mar 8, 2010I have been trying to read the cd toc in one go from the API, I can read it OK with a single byte array, but I can't find a way to fill the formatted arrays
Code:
'ORIGINAL STRUCTS
'MAXIMUM_NUMBER_TRACKS = 99
'typedef struct _CDROM_TOC {
' UCHAR Length[2];
[code].....
Add & Delete From Arrays Of Structures?
May 22, 2011what is the best way to add, delete elements from arrays of structures structure
vb
Structure Proxy
Dim Server As String
[Code].....
Cycling Through Data Structures?
Jan 21, 2010I am currently working on a project for myself which looks through employee's information to find their availability to work. I've tried making a structure which holds the employee's information but I can't think of a good way to create different instances of it and store information in it at runtime. I'd prefer to load the information in at startup and not have to declare each employee and information. I am very new to Visual Basic 2008 but I have a good grasp of arrays from C and C++.
View 3 RepliesDifference Between Classes And Structures
Oct 23, 2010I know that Structures are value types and classes are reference type, i know that since structures are stored in stack they are faster to use i also understands that structures can not use the Inheritance concept but still in most examples i see i always see that the authors use classes when building something like BBL library, if structures is light-weight compare to classes and i don't need it to be inherited should i use structure instead of class?is there a rule of when to use class and when to use structure ?
View 2 RepliesInclude Functions In Structures?
May 1, 2012lets say its something like[code]...
i want to add a function like this inside the structure
Initialising An Array Of Structures
Nov 7, 2009I have a Structure, and I am having trouble initialising it. Specifically when I try to populate the Vector3 variables, it tells me that they are Nothing, so I need to make them New when the array of this structure is declared.[code]Structures cannot declare a non-shared 'Sub New' with no parameters.I have no parameter to supply, and this will be an array so I'm not even sure how I would supply it.The second option to fix the error is to make the Sub New shared, but then I get other errors: Cannot refer to an instance member of a class from within a shared method or shared member initializer without an explicit instance of the class.Does anyone know how I can resolve this. My end goal is to have an array of this structure type with the Vector3s ready to use.
View 6 RepliesIterate Through A Collection Of Structures?
Mar 10, 2009I have created a collection of structures. Each structure, of course, contains fields.
Lets say something like:
Public Structure clientStructure
Public ID As String
Public firstName As String
[Code]....
How can I access a field of a particular structure using for.... each?
That is, how can I retrieve out of the collection (lets say item 5's) firstName, using for...each?
Lists() And Data Structures
Sep 1, 2009Can a list class in vb.net contain Data Structures ?
View 1 RepliesLoop Structures For A ListBox?
Jul 26, 2009Just a little frustrated with a simple error in a listbox result on a mobile application.Here is a sample of the results I should be getting:
The inputs are 50mph & 4.5 hours
Hour distance
1 50
[code].....
Need To Have An Array Of UDTs(Structures)
Feb 21, 2012I need to have an Array of UDTs(Structures). Elements have to be added (at end) and removed (from anywhere). The different values of the elements need to be changeable.
I know how to implement it as an oldstyle array, but wouldn't it be better to implement as a List ( of T)? and if yes is such a procedure possible?[code...]
Optional Structures As Arguments?
Mar 16, 2011It says that I can't have structures as optional arguments.That's really annoying for my program. Isn't there any way to circumvent this?
Sub fa(Optional ByVal colz As System.Drawing.Color = Color.AliceBlue)
End Sub
This example cannot compile
Restricting An Interface To Structures Only?
Aug 4, 2011I have an interface IDigitalState defined as
Public Interface IDigitalState
ReadOnly Property Code As Integer
ReadOnly Property Name As String
End Interface
[Code]....
What I wanted to do was declare a variable as a nullable type of IDigitalState. I understand why I cant do this because the interface may be implemented by a class which is not allowed to be nullable. Is there a way to define the interface so that it can only be implemented by a structure.
Save An Array Of Structures In .NET?
May 31, 2011I have 2 Structures
Public Structure One
Public ItemOne As String
Public ItemTwo As Integer
End Structure
[Code]...
Results In an Unhandled exception. Bad Record Length. and then If I close it and reopen it I get an 'Unable to read beyond end of stream' error. So what is the best way to save an array of structures? Binary Reader/Writer? and why does this way not work (Even if its derived from VB6)
Saving And Writing Structures?
Jan 29, 2011The following is a mini version of a data structure that I need to be able to write & save to disk. Can someone give me a sample of code needed to do this
Public CardType
Card(0 to 52) as Integer
Suit(0 to 52) as Integer
[code]....
Sort An Array Of Structures In .NET?
Nov 17, 2009I have an array of structures:
Structure stCar
Dim Name As String
[code].....
Sorting Structures By Different Elements?
Mar 30, 2011I have a structure
Structure record
dim firstName as string
dim lastName as string
dim phoneNumber as string
dim email as string
dim address as string
end structure
