Restricting An Interface To Structures Only?
Aug 4, 2011
I 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.
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Jan 20, 2009
I 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]...
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Jun 2, 2010
I 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 ".
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Dec 15, 2011
Im using a datagrid for user to enter input. However,im restricting the grids to some value.My grid is actually not bounded to any database. so,here is my requirement: whn the form is getting displayed,all grids are getting displayed.,which dont want.,only row2 shld get displayed to user after he'l finish entering values in row1.. im using vb.net as front end and access as backend..
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Aug 20, 2009
I've been tasked with creating a kiosk style system to browse a college library catalogue. It's all gone really well (unusually) and I've just shown my first version to one of the library bods. They're very happy with it but want to know if I can sort it so that folks can't navigate away from the library pages.I know how to prevent explorer opening a new page but not sure how to limit the browser control to one domain.
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Dec 15, 2011
i want to restrict -ve values entering into access database table.im using vb.net as front end...
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May 12, 2009
i am having a problem with either my algorithm for restricting an angle between lines. I have a diagram of my problem at the following linK: [URL] In the above diagram, i know the positions of the Points marked on the diagram. The Black lines represent where the lines are currently, i want to move the lines so that they are at right angles to one-an-other (i.e: they are perpendicular) if they are moved to not be so. This is represented by the gray lines.
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Nov 25, 2009
I have a textbox that is for National Insurance Number, so I want the first 6 characters to be letters and the last to be a number. I know I need to use the Is Numeric function but I cannot get it to work.
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Aug 15, 2011
i wanted to restrict my text box to have only 10 characters.I have used the following code
[Code]...
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Jun 21, 2009
can anyone help me in restricting characters or numbers in a textbox?
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Nov 21, 2009
I want to restrict the number of characters you can put into a textbox.
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Nov 5, 2009
I want to create a property for a custom textbox control that accepts only positive integers of a predefined range, say 1 to 20, with 8 as default. I can declare the property as Byte or UInt32, but that would still accept 0 and the upper limit is bound by the range of the type and there would be no default setting. When I use an Enumeration I'd have to create a list of all possible inputs, but when I want an upper limit of 1000
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Apr 11, 2010
I want to create a textbox user control which accept only numbers.
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Dec 8, 2009
I have developed a Windows Forms application using VB.NET and MS SQL Server 2005 Express Edition. My database name is 'AC'. I do not want ANY user, SQL Server or Windows authenticated, to access, read, write to, update, drop or take backups of this database, except this login 'Adel'. So my connection string looks very similar to:[code]What configurations should I make in the MS SQL Server Management Studio 2005 Express Edition to 'Adel' login, 'AC' database, and all other logins to accomplish this?Given the following:I do not own the server; my client owns the server. They have a domain set up (LAN network).They have ASP.NET applications running using other databases on the same server. However, these applications have nothing to do with my database 'AC' or login 'Adel'.Some of their applications do not specify 'User Id' in the connection string; they use 'Integrated Security=True'.
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May 5, 2011
I need to perform some validation for a computing project, How would I restrict the user from entering symbols into text boxes?
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Aug 5, 2009
Any way (outside of writing rounding routines) to restrict the number of places after the decimal in a Decimal data-type variable?
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Jun 8, 2010
the first is validating numeric input in a textbox to make sure it's got two decimal places. I think this should be really simple, but I'm totally missing it.The second is adding an extra summary line to a listview. I have it working with all the data required, but I need to add an extra line at the end showing some totals. How do I do this?
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Jul 20, 2009
I'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]....
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Jan 12, 2010
how to create a user interface in a game such as the application XFire using Visual Basic?
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Oct 19, 2008
I'm working on a design project where I have to use a Graphical User Interface that contains a drag and drop form. It consists of having a window dropped on a wall. Both of them are images to scale. I would like to know what kind of code I would have to use to show the x and y coordinates of one of the points of my window when dragged so when I drop it, I'm dropping in it on the desired coordinate of the wall.
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May 18, 2012
I was wondering if I could elicit some tips on how to procede with an interface design approach.That is. What is a good way to go about establishing a "work area" where one can have multiple "floating forms" in this area.Can you have a form which occupies the entire windows desk top and the other forms "float" in this space? the "floating" forms would need to interact with each other where pressing buttons etc on them would affect other forms on the "workspace") Or what would be a good way to start accomplishing that? Or is there a better way to get the same effect?
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Apr 21, 2010
I'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.
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May 21, 2012
Is this where i would post a picture of my interface and get feedback on changes for easier use? If not is there someplace on this forum or any other forum to do this?
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Mar 28, 2010
What is the different between these 2 structures?
Structure INPUT
Public dwType As InputType
Public mi As MOUSEINPUT
Public ki As KEYBDINPUT
End Structure
[Code]...
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Nov 18, 2011
in the codebase i'm maintaining there is an old interface. Let's call it IFoo. It pretty much became obsolete and replaced with the Interface INewFoo with a change a few weeks ago, but for backwards-compatibility purposes, i wrote a wrapper class which implements INewFoo and takes an IFoo in the constructor.To clarify, consider the following code.
Public Interface IFoo
Sub DoStuff()
End Interface[code].....
For both interfaces, the implementations are loaded by scanning a few assemblies with StructureMap. Now, let's get to the bad things. Most implementations for the old interface were put into forms for reason i can neither understand nor change. Because those tend to be displayed and disposed, i have to create a new instance every time i use ObjectFactory.GetAllInstances(Of IFoo). Thats still no problem, but i'd like to register a INewFoo-Wrapper for each registered implementation of IFoo, so that i can just use ObjectFactory.GetAllInstances(of INewFoo) and get all implementations of IFoo AND INewFoo.I can't iterate through the implementations of IFoo and register a wrapper for each one because as far as i can see, you can just register those with instances.Wrong code below:
ObjectFactory.Configure(Sub(config)
config.Scan(Sub(scan)
For Each ass In assemblies[code].....
My question is: Is it possible to register a wrapper for each implementation of IFoo which always creates a new instance of the implementation before creating a new instance of the wrapper?
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Feb 7, 2011
I want to declare a property as an interface collection of an interface, and I want to instanciate the explicit type later, in the constructor. Something like this.
Public Class LicenseFile
Implements ILicenseFile
Public Property Collection As IList(Of ILicenseFileDataNode)
[Code]....
In short, the question is "Why It Didn't work"? This is a simplified scenario, but It's easy to take a workarround, But I need understand the reason because It's fails.
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Dec 17, 2009
I'm using interface with relay and interface is connected to computer on COM (serial) 9 pins port. In Visual Studio 2005 I'm using this
SerialPort1.Open
SerialPort1.DtrEnable = True
SerialPort1.Breakstate = True
[code].....
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May 14, 2011
Structure 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]...
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Jun 5, 2010
Is 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"
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May 24, 2009
I'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]....
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