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.
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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.
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i am currently trying, to create some sort of a business logic within my class, that contains information about a machine, now this machine once sold, can be re-sold by its owner. the company needs to keep track of the machine and its owner for warranty claim purposes.the class takes in two values, a from date and a to date.now when a new owner is added to the owner collection of the machine, the TO date of the previous owner should automatically be updated to one day less than the From date of the new owner that is being added.
View 1 RepliesI have tried searching all over the web for this logic. Got many but half of them did not match what i was looking for and half were malfunctioning.I want to calculate business working hours between 2 datetime, where in I should be able to set the working hours as well as weekends and holidays should not be calculated.
View 7 RepliesI have several successive web pages going through a checkout process and they each have tons of business logic that time restraints limit me from pulling out and wrapping up elsewhere in the code the way it needs to be. What would be a good method for calling each one of these pages' Submit buttons in order from one page to the next?
The way I was going to do this was to (laugh at me go ahead) make PUBLIC all of the submit buttons' code and just call them. But what I have found is that all of them have, of course, certain calls to controls on their pages where it might make a label visible or change a text property then that will crash the app due to a null reference. I believe it is basically saying if the webpage is not visible then it is not going to let the code start setting certain GUI properties of the controls on the page. It seems like I recall this in VB6, too.
Anyway, what would you do if you were in this situation? I have started down the path of creating a flag that says whether or not I am in expresscheckoutmode and, if so, it just doesn't do the "illegal" things mixed into all of the code like making labels visible and all that. But that also means that I have an IF BLOCK everywhere where the code simply changes a label. It junked up the code bad and I still haven't finished that implementation of it all. I wanted to come here to ask the collective mind what programming principles I can best apply here.
I also went though the whole "ASP.Net in 24 Hours" book by Scott Mictchell. I followed everything that went on in that book and built the final project successfully. I also used the tutorials here to better understand the whole Membership Provider/User tables setup that was going on in the book. Next, I thought I would learn more about accessing data for ASP.Net since that is what most application do.I went through the first Data Tutorial here. I seemed to understand what was going on just fine.The second Data Tutorial seemed to just show a lot of VB code to build the Business Logic Layer. There was not much explanation about how to do it yourself.I think I can keep going in the tutorials here. I downloaded the code from the second tutorial and went through it.I am guessing that the code in the second tutorial was given just to proceed with the overall project that is being built throughout the tutorial sequence.
View 2 RepliesI 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 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?
View 5 RepliesHow 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
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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
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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
View 12 RepliesI have a shopping cart ListView control backed by a custom object that has methods for selecting and deleting. In the ListView, one of the columns is an ImageButton that is essentially a delete icon, with the CommandName parameter set to CommandName="Delete".
My issue is related to updating the shopping cart ListView on delete; as the delete method is stored in the custom business entity object, I am having trouble in terms of updating the calculations made inside the cart (we have deleted an item, so I need to recalc shipping, taxes, etc).
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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.
What I mean is that when I make queries on a Parent Form. Child forms can also retrieves the datatable /datarows from its parent form.
View 3 RepliesHow would you structure a large project with most of the business logic already inside stored procedures?We are moving from classic ASP to ASP.NET (VB) and pretty much all the business logic is inside stored procedures.Getting the logic out of there is pretty much impossible since my boss doesn't want to (too expensive, takes too long, no "real" added value).I was thinking about making a presentation layer made of aspx pages, a business logic / data access layer that would basically get the data and interact with the existing stored procedures and a business entities layer that would be made of classes (for entities and collections) containing the information to interact between those two layers.The reason I wanted to make those layers was to be able to reuse most of the code without duplicating it.
View 4 RepliesI'd like to have an updateable DataGridView that's bound to a database-driven business object. It needs to handle all aspects of CRUD and be sortable and filterable as well.
Most of them simply bind to an object (non-database, manually filled) and do not allow you to Add, Delete, and Edit records. Furthermore, they basically never show how you would perform sorting and filtering.
I think the biggest things I'm not understanding are:
1) How do you make the DataGridView perform additions, deletions, and edits on an object.
2) How do you program your object to handle additions, deletions, and edits. Do you just need methods that use ADO.Net, NHibernate, or Linq to SQL (or any other CRUD handling mechanism)?
3) How to make this filterable and sortable.
Is this overly difficult to do or why am I have so much trouble finding examples for this?
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...")
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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?
View 1 RepliesI 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 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]...
View 2 RepliesI 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(,)
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my form displays locations and owners for a same product, the forms have a data grid view that actually takes in the details of the location and owner of that particular product. a product can have multiple owners and locations once its manufactured over time, the forms actually display this all i need is some kind of business logic that can actually manage the historical events of the location and the owner that when a user actually goes in and adds a new entry, the end date of the previous owner gets reduced to one less than the start date of the new owner. this in formation is stored in business layers called the owner collection and the location collection, i am not able to actually inherit or call the location or the owner collection class in the classes.
View 1 RepliesMy question is in two parts:
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).
I have a basic three form application. It doesn't seem to close after navigating through forms. If I were to open the application, and the main form is displayed. If I press the X button, the application closes fine(Goes from processes) If I were to open the application, and then navigate from the main form to another form using me.hide & form1.show, and press the red X on Form1, the application again, closes fine.
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.NET developing and have a simple question, i've been stuck on this for a while and searched many forums first with no solution so i'm posting myself. In VB for excel i've used Screenupdating=false to disable the screen updating however now i'm creating a visual studio 2010 windows forms application and its not showing up as a property. Here's the code i've tried.
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I am trying to use values from form1 in my project, in form2, but Im not sure how to do it. I've tried
txtboxTotal = (Form1.vsbLength * Form1.vsbWidth) * Pattern
But I get: operator '*' is not defined for types 'System.Windows.Forms.VscrollBar' and 'Systems.Windows.Forms.VscrollBar.'
I have the requirement to create an application that has multiple front ends developed using Windows Forms, WPF, ASP and Compact Framework Mobile Forms.I would like to be able to create a series of obejct representing the business logic and have this logic accessible from the various front ends available. My first thought was to use remoting as I'd like to be able to pass the business objects back and forth between client and server but the compact framework doesn't support remoting and also transferring a full framework business object to a compact framework business object doesn't seem possible.My next thought was to use web services but again the passing of business objects seems to be very hard to accomplish. Without doing this I would have to create individual web methods for each business operation.
Finally my next option is to use sockets and write the whole client/server logic within some classes and expose them to the UI/Business layer. My only problem with this is it is not scaleable should the number of clients increase dramatically whereas using remoting or web services I can host the solution via ASP.Net.Does anybody have an ideas on the best way forward for this or even have any input on how they would write an application that required a windows form, wpf, asp website and mobile device GUI all of which want to use the same business logic?
I would like to know if its possible to start up a second windows forms inside the parent form. Ex: A button is pressed and a new form is showed. I would like to keep that new form inside the parent form, and have it not be able to go outside the parent form.
View 2 RepliesI am writing a program for my A-level coursework But for some reason I got this build error this has never occurred to me before, I have no idea why I can't use string for the name of my form.
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