Inheriting Class Or Control - ListView, TreeView - Distinguish Between Built-in Methods/property/events
May 15, 2012
When inheriting class or control e.g. ListView, TreeView, etc..., what is the best way to distinguish between built-in methods/property/events and mine?
Currently, i start my methods/property/events with "aa" in order to make them at the top of auto complete list.
When inheriting class or control e.g. ListView, TreeView, etc..., what is the best way to distinguish between built-in methods/property/events and mine?Currently, i start my methods/property/events with "aa" in order to make them at the top of auto complete list.
I am using an inherited form extensively for the first time, and I'd like to know if what I'm doing is correct.I have a base form with a grid and four buttons (Add, Edit, Remove and Close). There is no functionality in any of the button click events, as the specific implementation of each derived form will be different. The only exception perhaps is that the Close button closes the form. The only reason I am using a base form really is because I've many forms that look the same.How do I now expose the button click events to any derived forms? The only straightforward way I could think of was to have the button click events call an Overridable method, which I then override in the derived form:
Public Class frmTableBase Private Sub btnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click Me.AddButtonClicked()[code]...
Is that the correct way? It seems a little bit overkill to have to do this, although I can't think of another way really... Perhaps I could add the Overridable keyword to the event handlers themselves (and make them public)..?I'm doing it the way I showed now however. It works, but I'd just like to know if this is the generally accepted way of doing this.
I've not got any issues with Cross threading but I hate the amount of work involved in sorting cross threading issues out.I thought today that my inherited Listview Control could have built in cross threading capabilities; it would decrease the amount of work on the form, and tidy things up.I've got this to work (EnsureVisible method), BUT I'm a little stuck when it comes to the Items.add below is my example control.
I have another question about my customizable Menu/Tool/StatusStrip control.
I have three controls called CustomizableMenuStrip, CustomizableToolStrip and CustomizableStatusStrip. Each of those controls has a property called Appearance, which accepts an instance of a component called AppearanceControl.
The AppearanceControl component basically exposes all color properties for the customizable strips, so the user can edit them, and more importantly exposes a ToolStripProfessionalRenderer which the three strips have to use. This way the three strips are rendered with the colors the user chooses in the AppearanceControl.
Now, I'm wondering if I'm doing things the right way. When any of the color properties in the AppearanceControl has changed, all the strips that use that particular AppearanceControl should have their Renderer set again, and should be invalidated.
I figured the easiest way (and probably the only way?) to go about this was to have the AppearanceControl raise an event (AppearanceChanged), which the three strip controls listen for. When that event is raised, the strip controls can set their Renderer to the Renderer that the AppearanceControl exposes, and then invalidate themselves.
control which will need to be reused in several forms in my program. It basically consists of several buttons in a panel. To start with, what I need to do is get the button values from the control into a text box on the first form. But I don't want to have a method calling the textbox directly from within the control, because then it won't be reusable in my other forms. Is there something I can do in VB like parentform.textbox.append for example, where you can generically call the methods of the form in which the control appears?
I want to add a custom property to a button in window form. Currently i am using following code to create my logic. but i want to create an enum value for a button control.
after a week of trying to find a control that combines the Treeview/Listview, a so-called TreeListView, I gave up. The ones I found are either buggy or have too many features (making them heavy).The best way for my personal needs is probably to use an ownerdrawn Listview and doing the indentation (expanding/collapsing) myself.There are a few problems:
1) I can't get the Plus/Minus images to show properly. If I expand a 'node' and collapse it, then the Plus image doesn't show. If I expand two 'nodes', then the Minus image of the first expanded 'node' becomes a Plus image again.
2) Clicking the Plus and then Minus image too fast causes weird flashing behaviour of the 'node' expading/collapsing.
3) Somehow I need to be able to update the Listview in real-time. I know I can use ListView.RedrawItems to refresh a single row, but I need some kind of structure to know which 'nodes' have been expanded. When a 'node' gets expanded, then everything below gets a different index.
How do I distinguish copying data and a pointer when using a class?E.g. public class myparams var1 as integervar2 as intergerv3 as stringend classmyvar as new myparamsmyvar.var1=1myvar.var2=2myvar.v3 ="hh"othervar as new myparams
I want to copy all of myvar data into othervar in one go.. without doing othervar.var1=myvar.var1 etcusing othervar=myvar" Looks like its just copying the pointer of myvar into othervar? Can I copy all the class data in one go? VB2008 user
I inherit from ListView. I want my control to have an AllowCheckBoxes property rather than a CheckBoxes property. Listview.Checkboxes is not overridable. Can I add attributes to Listview.Checkboxes? Maybe the following? <Browsable(False), DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)>
If not, does the following make sense? <Browsable(False), DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)> Public Property Shadows CheckBoxes() As Boolean Get [Code] .....
if I wanted the button onclick event in a different class how would I declare it?
when I refer back to the form it says I need to declare with events..
Private Sub btnAddToLaneFilter_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Dispatch.btnAddToLaneFilter.Click If Me.txtCriteria.Text = "" Then
I am not sure how much work there is to inheriting from the web client class.
Currently I am using it in my project. And I can't change to anything else. The customer would like to have a timeout after a certain period of time. The web client doesn't have this.
So rather than re-invent the wheel, I am thinking of inheriting from the web client and adding this property.
I am not sure how clear my question is by the title, but I am trying to make Class methods instead of Instance methods in Visual Basic that way I don't have to waste memory and code creating temporary objects to execute methods that don't need instance variables.
I am not sure if you can do that in VB but I know you can in Objective-C by using either a "+" or "-" sign in front of the method declaration. And in C++ (at least I think, I can't remember) you put the static keyword or const keyword in front of the function.How would I do this in VB if it is possible? Or should I just make a separate set of functions that are not members of a class?
I have a list view with Two Columns. I want to set text in the Column Header as "Bold" & Text Align as "Center". But the text in the rows of the list view not required bold & center.
I want to implement a priority queue class. When an item is added at a higher priority it is pushed to the front of the queue instead adding to the end of queue. Simple few lines of code
I've created a class called connector. By clicking on project and adding a class.And I want to inherit from that class in the forms But I get this error.
Base class '<baseclassname1>' specified for class '<partialclassname>' cannot be different from the base class '<baseclassname2>' of one of its other partial types`
what do I do?Here's the class named connect.vb:Imports MySql.Data.MySqlClient
I have a class that is stored after serialization and compression.Is there any event built in the class that is fired automatically when a class is deserialized and ready to be used??
Can a custom control NEW Sub be the only one that executes when Inheriting from an existing control please?I am Inheriting from TabControl and I do not want the base New Sub called, is this possible?In other words, I do not want TabPage1 and TabPage2 to be added.A Form has an Activated Sub which runs once a Form is activated.It is a pity that Microsoft have not got such a method in the baseControl Class otherwise I could have used it within a custom TabControl.
Public Class Form1 Private Sub Form1_Activated(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Activated End Sub
Most of our code base is in VB.NET. I'm developing a project in C# that uses a lot of the assemblies from the VB.NET code.There are three relevant classes in VB.NET:
I want to define a generic interface which will be implemented by an abstract Generic Class. Basically this generic class is a collection class of any class. Interfaces are in a separate project saved as FileReconciliation. Here are the interface definitions
Interfaces Imports System.Collections Public Interface ICollectionCommon(Of T As Class) Inherits IEnumerable Function Exists(ByVal oKey As Object) As Boolean [Code] .....
Is there a (simple) way to connect a textbox, label etc. to a property in a class?I have a project with a complex series of dialogs to enter data into a list of a costum class describing an experiment with many parameters that are stored as properties (both simple variables such as strings and integers, but also more complex ones).I need both to be able to update the list of my experiment class, but also to go the other way to populate the dialogs from the class.It can of course be done outside the class and the dialogs in separate subroutines. This however, quicly becomes unmanagable and hard to maintain as the dialogs and experiment class is expanded with new elements.If there was a simple way to connect say a textbox or label in a dialog with the appropriate property holding the information it would make it much easier.