Vb 2005 Form Inheritance - Multiple Forms Are Opened?
Nov 7, 2011
Several years ago, I created a nifty data entry form that is called from a main menu. Due to recent user requirements, I had to create another form that is very similar to the data entry form. To prevent duplicate coding and testing, I created a class to inherit the existing data entry form. The issue is when I leave the class and return to a sub menu, the class is opening the main menu and the sub menu. How do I only return to the sub menu without the main menu appearing? Here is a snippet of my code. You'll have to scroll down to the very bottom to see the section that is causing issues. BTW, I coded the application in such a way that only one form should be open at a time.
frmMenu (main menu). This is nothing more than a bunch of buttons that allows the user to perform various functions.If user clicks button #1, open the data entry form:
Dim objFrm As New frmDataEntry
bolOkToCloseForm = True
Me.Close() '--- close the menu screen
I am developing a windows based application in VS2005. I want all my form to be inherits from one of my class e.g.ParentClass but indeed the windows forms already inherits windows.forms.form class. what I have tried is that, I inherit "windows.forms.form" in "ParentClass" and all forms inherits my "ParentClass". But in this case when I view the design of the form IDE gives error.
I am currently working on a program that has several buttons in it lined up. Each button goes to different applications (.exe programs). The program I am making is suppose to be a fullscreen program and won't let you see any of Windows when it's running.
Therefore I want to make a "back" button that always stays on top of any application and when I push it it will take me back to my WindowsForm (startpage of the program).I am also wondering if you can make it so all .exe programs only can run ONCE. So if I press one of the buttons saying "open notepad" I want it to work so it can't open Notepad once again making it two notepads open. Just go back to the first Notepad opened.
I'm facing a problem regarding multiple inheritance in VB.net:As far as I know VB.net does not support multiple inheritance in general but you can reach a kind of multiple inheritance by working with interfaces (using "Implements" instead of "Inherits"):
Public Class ClassName Implements BaseInterface1, BaseInterface2 End Class
That works fine for classes but I'd like to have an interface inheriting some base interfaces. Something like that:
I am currently working on a framework for applications developed by my company, my boss wants to have a switchboard and a MenuStrip, where the entries and their actions are controlled by a database.
Now I've dealt with all the code to get them working. But the problem that I am facing is that I have duplicated code because each of the classes have the code that deals with ensuring the user has the right privileges and the code to deal with when a user clicks on an item.
Normally I would move this code out into a class and then have each of the classes inherit from the class, but because the switchboard already inherits from the Form class and the customised MenuStrip inherits from the MenuStrip class.After doing some Googling the only answer I have been able to find it using an interface for the functionality, which is obviously not exactly what I want.
Anyway I was just wondering whether any one had any suggestions on what I could do to deal with this problem, as I would like to avoid having duplicate code as much as possible.
I have a library of graphical controls used to display values from a remote device. The controls are typically graphical objects such as a digital meter, analog meter, vertical bar, etc. I first create these controls with a value property. The control will display the value property, e.g. the meter needle will move to the position representing the value.
The next thing I do is to create a new control that inherits the previous discussed control. The new control adds properties that allows the value to be set from values retreived through a communication component. My code that does this is 99% the same for all of the controls. Since I already inherit the graphical control, I can not inherit the class that retreives the values from the communication component.
I have a class, GControl. It's pretty much a Control class clone with some improvements. It doesn't inherit from Control, because that would be a huge mess, and it needs to stay that way. However, to add a GControl to a Form in the first place, it needs to inherit from Control. So, I created a new class, called GForm, that inherits from Control and draws GControls in the OnPaint method. However, it should also inherit GControl, because it needs (1) to be able to be a GControl's Parent and (2) to be able to have a GControlCollection property. The way I've made the GControlCollection is so that it must be created with a GControl as its parent. I could change how GControlCollection works, but not the Parent property. Does anyone know a way to get around that?
Here's what the property looks like:
CODE:
And a few methods (like Invalidate()) need to be called on the control's parent.
I m trying to understand Interfaces so that I can implement them in my programs but I m not able to imagine how should i use them.Also give me some eg of using them with multiple inheritance in C#
I have 10 forms and say 5 text box's on each one so a total of 50 of these text box's. But the program is only using one of these forms only (user selects the 1 Form out of the 10) so I was wondering can these forms Share the input text box's? I am thinking NO, if so then the only thing I can do is just use 5 shared variables that all the forms can utilize.
The TextBoxBase class is marked MustInherit, but I can't inherit off it. When I try to, I get a squiggly line and the message System.Windows.Forms.TextBoxBase has no accessible Sub New and cannot be inherited.This is kind of pretty inconvenient, as I need to extend this class. (And before you ask, I need to extend this class because TextBox derives from it, and I want to Shadow the TextBox class's TextChanged event - but the TextChanged event is declared in the Control class, not the TextBoxBase class. So there.)
I have a program that uses two forms. The program opens to the Main form, and the user can navigate to the other form from the Main form through use of a button. Here's the way I've currently written it: When the Main form loads, it declares and instantiates the other form during the load procedure. When the user presses a button, the second form is displayed by means of the ShowDialog method. On the second form, there is a Return to Main Screen button which closes the second form, bringing the user back to the Main form.
So, here's the structure of the code:
Code: Public Class frmMainForm
Dim frmSecondForm As New SecondForm
Private Sub btnSecondForm_Click(blah, blah, blah) Handles blah, blah, blah
[CODE]...
Here's my reasoning: Originally, I wrote the code so that a new instance of the second form was created every time the button was pressed. The problem was that whatever data was displayed on the second form, previously, was lost when the user returned to it a second time. Since the user would be switching back and forth between these forms, frequently, I needed that data to persist.
What is the best practice for accomplishing this:
1) Declare and instantiate the second form on program start, as I have done, and use the button simply to show the form?
2) Declare and instantiate the second form each time the button is pressed but maintain the variables on the Main form and pass them ByRef to a custom constructor for the second form? Is this even possible?
I have to make some automatization on a web server, I use Visual Studio 2005 Visual Basic Windows Console Application. I want to make a load/performance test of the web server, so I open several Internet Explorer instances, and I login the application, that is not a problem. But after that I have a mess on the page and I cannot make any more automatization...The composition of the page after the login is like this: I have the default form, another form and a multiple data window(mdw) controller, which dinamically can switches the forms on this part.
The problem is that I don't know how to access the controls of this mdw forms. I couldn't find much about this mdw controller and I am not an expert.
My code is here:
Imports System Imports System.Diagnostics Imports System.Web.Ui.Webcontrols
I have been creating a call management application and I am having a problem with something that I have spent weeks on trying to get working and nothing I try is working for me. My application is an MDI application written in VB.NET 2005 Professional, using .NET Framework 2.0. It uses a back end database using Microsoft SQL Server 2005.When the MDI application launches, a form is displayed to the end user asking for phone number (MaskedTextBox) and a partner name. The partner names are within a ComboBox.
When the end user types in the phone number and selects a value from within the ComboBox, s/he clicks on the start button. This then opens a second form. The phone number from the MaskedTextBox is to default in a second MaskedTextBox (this I am able to get working without issue.) The partner name selected from the ComboBox is to default on the second ComboBox. This is the part where I have been working on it for weeks and not able to get it to function.
The second form has many ComboBoxes, all of which pull down items from a particular table within the database. Some of them are editable and some are not. The ones that are editable are also auto complete Suggest/Append on the ListItems.I wrote a sub to handle the population of these ComboBoxes and also to handle if they are editable or not. All of this is working. However, my main issue is that I can't get the value on the second form to default to what ever was selected on the first form. I do not get any errors but regardless of what I do, the second form always stays as the first item in the list regardless.
The code I am using is as follows:
<CLSCompliant(True)> Public Sub PopulateDropDownListFromDB(ByVal cboName As Elegant.Ui.ComboBox, _ ByVal TableName As String, ByVal ColumnName As String, _ ByVal UseAutoComplete As Boolean, _ ByVal UseSQLDistinct As Boolean)
I've got a tab control and want to dynamically add tabs depending on the output from a database. I can easily add a new tab, however I want to inherit the controls and layout from the initial tab.
I've written an application with about 30 forms and am almost ready to publish, my biggest concern though is that i'm not sure if its a normal thing to do having all these forms and hiding, disposing and showing forms throughout the use of the application.I've toyed with the idea of converting to a MDI Child / Parent interface as well as having one form with lots of subcontainers that are hidden and then hiding / showing them as the navigational buttons are shown.Ive worked on this application for about 8 months now, but would be happy to rewrite the interface and appearance of it if i know that it is not generally an acceptable practice having forms flashing open and closed while navigating through the application.
I will know how do I work with the opened excel instance, when I use multiple userforms. I have on my form1_load open a excel file. Then I observed that on my next userform, was unable to write to that file again. Project have no instance of APP.workbook.
I have my program (Student Pad - The Project - Haxaro Freeware) and it has gone fairly large. In my next release, i would like to know how many user approximatly are using it, so when ever a user opens my program for the first time on that computer, it sends me, or my website a report telling me that it was opened on a computer. so if 4,000 people download and open it, i should get 4,000 emails or reports
I have multiple tabs opened in 'any browser' and one of it is titled 'LAME', how can i make links open(by buttons) in that tab? I have a simple form with two buttons,
Button one: Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Process.Start("http://www.google.nl/sub1") End Sub
I have an MDI parent(MDIParent1) form with a child form(frmMain).The child form got a Tabcontrol(TabControl1) in it.I am trying to load other forms(say form1) in my application to this tabcontrol as tabpages. I use the following code for that
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).
I'd like to give a homework assignment to a person learning VB.NET. I'd like it to use basic inheritance and a variety of data structures including queues, lists, arrays, or stacks in a windows forms application. I was thinking of a pizza-ordering application. This would allow them to utilize some basic inheritance and practice using .NET UI elements.
I am developing a application where a url is supposed to be passed to Internet Explorer using a search button. But if more than one url passes it should open in same instance. I dont want new instance to be opened every time. I am using SHDocVw.dll for the same. I have coded for opening a new IE instance and URL is getting passed successfully. But meanwhile if I close that open IE then I get exception and my program dont work.
