I have two forms A and B. B is a child of A - i.e. I have a button on A that pops up form B. I want B to be able to access and change data (e.g. an instance of an object etc.) in A and also to call some function in A. At the same time I'd like to preserve the right to alter the data in A without opening B. I've achieved this using the following (i.e. by declaring the object and method as Friend):
Public Class frmA
Friend _data as Hashtable
Friend Sub GetData()
If _data IsNot Nothing Then
_data As New Hashtable
Is there anything inherently wrong with the what I've done and if so how can I achieve a similar result? (It seems to work - I can read, add to and change the values in the _data Hashtable from within form B and when B is closed the values persist i.e. I can access the changed values from within form A. I just dont know if its a horrible fudge).
I am working with several RFID readers that perform different function in my vb.net program. Currently each reader port number is hard coded into the respective form. For example, reader 3 operates on COM1. However, this will be problematic when installing on different machines.
What I would like to do is have a "configuration" form where the user can select each reader and then select the COM port. Then all other code references these settings. What would be the best approach for this.
The only way I know to do it currently is to place this information in a small database and then have the forms reference that database, but it is a lot to do for such a seemingly trivial task.
I am sharing databinding when opening a detail form a summary form. The data is shared fine. What I don't know is how to save any data that may have changed, or to create a new record.[code]...
1) I am writing an application for a touchscreen which will have several different Forms - each of which will be full-screen. What is the best way to achieve this? Hide/show each Form as the user navigates between screens? MDI Parent with multiple Child Forms becoming visible 'on top'? Or is there a more elegant solution?
2) I would also like a 'banner' on the top of each Form (or always visible on the top of the MDI Parent, etc) similar to a 'navigation frame' on a website. This banner will display a clock with the current time, and the current GPS location (meaning that a Timer will be used to get/set these values every 1000 milliseconds). I thought of using a UserControl for the banner - but if this is used on multiple Forms then I will end-up with multiple Timers all waiting 1000 milliseconds to update essentially the same information.
Is there a best practice for this type of scenario? - my thoughts so far are using the "Main" Form for Global Timers, etc - but then how do I update all Form clocks each second? (without iterating through all visible Forms... which seems messy).
My question is, am I able to share a business logic layer seemlessly between the two presentation layers or is there anything I need to watch out for. I'd really like to not have any duplication of business logic, so any advice would be more than welcome.
I have an application built that has several forms. I use an XML file to store settings data (mainly folder names for data output) and I need each form to be able to access and modify the data. I'd also like each form to access functions from a main form (such as file parsing functions). I have read articles about properties and inheritance but I need some guidance as this topic is pretty confusing.
I have an application that needs to perform a series of different actions at specific points in time.To do this I have a timer with various actions that occur in its tick event.One possible action is to send out a few messages via a serial port and then wait (between 1- 300 mins typically) for the next timer tick.Another possible action is to continuously toggle one of the control lines on the serial port until the next tick (again 1-300 mins).
In most instances, i'm happy for everything to run on the main thread, but in the case of toggling the line endlessly, I thought it better to give it its own thread.My problem is that for the new thread to use the Serial Port, it must open the port. Likewise, it must close it before the main thread can have it back.
Here are 2 code snippets
Private Sub activityTimer_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles activityTimer.Tick Dim some variables here activityTimer.Stop() If speedThread.ThreadState = ThreadState.Running Then
I'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?
I have some icons and images that are stored as embedded resources in my form1.resx file. Is there any way I can access these resources from my Form2 without adding the icons as project resources?
How do I share text between forms?I want a box to popup exactly like a input box, but needs to be multiline, Is there any east way to do this or will I have to create a second form?If so, how do I share the string between forms to then output in a textbox on 1st form?
Also, I have VB 2008 Standard, and I want to build an application for a handheld, Is it possible to build an application and then pass it over to someone who has the professional version to make it work on pocket pc? Or does the entire build have to be on pro already?It's a very simple program...
I am trying to figure out how to seperate my business logic from my forms. This is my first attempt at doing this, but I would like to figure out how to handle events from multiple forms within a class. I have found myself routinely writing the same logic over and over in each form class and its time I figure out how to completly seperate out that logic in winforms so I can reuse the methods across all of my forms.
So basically I have this click event in form1: Private Sub btnSubmit_Click(sender As System.Object, e As System.EventArgs) Handles btnSubmit.Click
When I declare a variable as public, shouldn't it be available in another form? I am trying to write a windows mobile prg with 12 static mileage points, form1 has the 12 buttons for start point, but when I call form2 with the destination points, my start variable value is not carried over. I intend to then assign a mileage based on the two points and write to file on mobile device. We support 12 schools, and I want my employees to track mileage easily.
Public Class main Public start As String = "start" Public dest As String = "dest" Public miles As Decimal = 0 [Code] .....
i've almost completed my Yahtzee game except for the high scores function. I've got everything worked out except how to take the highscore variable from Form1, and share the data with Form 2
I need to share variables across two forms in vb.net. One of them is the main form and the other is a child form.
Create a static/shared variable in one of the forms and access it in the other forms via: Form1 frm = new Form1(); //creating object of parent to access shared variable frm.a = "abc"; // passing value
Send an instance of the main form to the child form when creating the child form. The variables can then be accessed via a property function. Create global variables in a module. This seems like the easiest option, but I doubt it is the best option.I also read something about delegates and events, but I don't know how to implement this.
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
I'm starting to put in a database into my application, however I'm drawing a blank on how to share a database connection among the dozen or so different forms in my MDI application. I'm assuming this has to do with interfaces or something but I can't find any relevant examples anywhere. Can someone help me out? Ideally what I'd like is when the app is loaded up there is a call to a function in the forms loading area which establishes a single connection to the mdb, that I can then call via any form so I don't always have to open/close connections everytime I need to update the db?
Here's a basic example of the mdb database access code I've got working:
Dim dt As DataTable = New DataTable() Dim OleDbTran As OleDbTransaction = Nothing Using connJET As OleDbConnection = New OleDbConnection("connection string here...")
I have a form that can spawn a child form, something like:[code]I want to be able to launch multiple children. Unfortunately, I seem to be getting conflicts within the controls of the children. One button will run the other child's control, etc. They also seem to think that their class-level variables are accessible to each other. Private Shared variables like the following are conflicting (one form thinks it's seeing the other form's "mp3file" variable as their own):[code]How do I spawn children forms that keep their controls and data separate?
I have a very simple 2D array, it holds a list of song titles, their genre, and their runtime. frmMain loads the array from a text file and allows me to manipulate it and boil it down to a desired (implicitly sized) playlist. i want to THEN pass that playlist array to a second form, frmPlaylist The problem i'm running into....When frmPLaylist calls the Property from frmMain I receive an error that VB cannot convert the string value to a two dimensional array. Simplified...frmPlaylist is all locked and ready to receive a 2D array, but frmMain seems to only be sending a single string variable. on frmMain
Public ReadOnly Property PlaylistOut() As String Get Return mstrTimedPlaylist(,)
Got 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.
I am new to the forum and new to the visual studio set up and have been working at a practical at home and have ran into some difficulty. The notes say that I am to declare several module variables below the section entitledI have the rest of the form complete but have been unable to locate where I am to place this code
Am new to VB, can anyone tell me very simple how to share the MAIN Bindingsource with an detail form where i want to edit 1 record from the main datasource? andreg
I am in a VB programming class and I am having an issue with a program that I created. The focus of the program is creating a class to do calculations and sharing the data with a form.
The problem that I am having is with a certain piece of data that is shared between the class and form. To be more specific, it is two check boxes that each have their own variable as boolean, done as a true/false if checked/unchecked situation.
When I step through the program, somehow the values get changed entering the class for calculations. For example if it was true, false, it comes out as false, true when the class accesses the data. There are other variables and data types that get pulled but these are the only ones that are being altered.
I have done programs in the past with VB6 using the winsock control to receive data to be processed. I would like to do the same thing in vb.net but I am having problems. I have done numerous searches and consulted numerous books and articles, but haven't found the best approach for accomplishing the following.
I would like from 1 to 20 clients to be able to send a string to the server to be processed. It would be nice to if the clients could connect to same port and use async processes to open/accept more connections. One of the books (Visual Basic 2008 Recipes) has a recipe for creating "Multithreaded TCP Server that supports Asynchronous Communications".
I am trying to base my program off of that example and modify it for my application. The problem I am having is how to share data with the Main form and the classes that handle the communications. The TCP class has two classes contained in it. One class for listening for connection, beginning the accept client and the other class (clienthandler) for completing the connection and getting the data. I would to be able to get the data from the clienthandler class and post on the main form. I have trying to have a public property for the data but I think my confusion comes in because the clienthandler would be created new for every new client. The mainform would not know how many of the new clienthandlers were created etc.how get the data to the main form and clear the data when done. I have even considered putting data into MSMQ and having main form pull data out.
I know a little about threading and delegates, as well as socket programming. I'm working with a VB.NET-compatible SDK called TrueVision3D to create a small online game for me and my friends. The problem is that I cannot for the life of me figure out how to pass data from one thread to another. I've created 2 seperate threads on seperate forms.
The first thread is created on a form titled FrmLogin, and it contains all the socket code. I need to be able to update variables in the second thread, which mainly consists of a render loop. The second thread is created on a form titled FrmMain. I'm not quite sure if it matters what forms the threads are created on, I'm just trying to give as much information about the issue as I can. I've tried using delegates and events to pass information from the thread back to the form it was created on, which works fine, but how do I pass data to the second thread from the first?
I have a PC with sql server 2005 express, my application works with it great, is it possible to install another copy of my application to a laptop that will move around and wont have access to the data all the time. trying to find something like SQLCE has(RDA)so it can see the data make changes and when it returns it submits all the changes. Is this possible and how can it be done.
