Custom Button Attributes

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  13 years ago

  by JimBoBJones

  Jim Bob

  , New Zealand

  Joined 13 years ago
  Hey. I'm a bit of a newbie to vb .net.
  I'm curious if it's possible some one could point me in the direction of some pre-written custom button (particularly with more attribute fields for info), or let me know step by step how to add some custom attributes for the default button?
  
  I've read a few items on adding custom attributes and writing custom controls, but I'm afraid they're slightly above my current understanding. I'd apprechiate it if someone could assist. Thanks.
  
  
  
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• • Reply

  13 years ago

  by TwoFaced

  Thomas Reynard

  , United States

  Joined 15 years ago

  What you'd like to do is extend the button class.  This is pretty easy and I'll walk you through a simple example.  Once you understand it maybe the more complicated examples you've seen will make a little more sense.  At the very least you'll have a starting point.

  1) Start a new project (windows application will be fine)
  2) Click Properties > Add class
  3) Give the class a usefull name like ExtendedButton and then click Add
  4) Double click on the class in the solution explorer to bring up the code window
  5) Under the class declaration type 'Inherits Button' and hit Enter
  
  
  
  

  If you don't know about inheritance you should do some research on class inheritance so your more familiar with it.  For now just know that by inheriting the Button class we've now created a Button with all the properties and methods of the standard Button.  As a rule of thumb if a control does mostly what you want you should try to inherit from it and then modify it to your liking. All you want are a few extra fields so this is definitly the right approach.

  6) Add a private string variable 'm_Field1'

  This variable will contain the properties value that we'll create next.  When creating properties I like to name the local variable using the convention m_PropertyName.  I've seen other nameing conventions like _PropertyName or mPropertyName.  Pick the one you like or use something else it's up to you, but be consistent.

  7) Type 'Public Property Field1 as String' and hit Enter

  The rest of the code for the property will be created for you when you hit enter.  Again if your not familiar with creating properties do a little research to familirze yourself with them.  In general it's good programming practice to use properties instead of public variables.  For instance declaring m_Field1 as Public and nameing it Field1 would have acomplished the same final result we'll have after we've finished the property.  However, I like to stick with properties for everything even if they are very simple like this example.

  8) In the Get portion of the property add the code 'Return m_Field1'
  9) In the Set portion of the property add the code 'm_Field1 = value'
  10) Run your program and then stop it. This should cause your control toolbox to refresh and your new control will be added to the list with the name 'ExtendedButton' or whatever you chose as a name.  As an alternative I believe building the solution will also refresh the list, but running it instead will save you the hassle of needing to save your project to build it.
  
  

  At this point you should have an extended button with an additional property 'Field1'.  This Button should also appear in your toolbox.  You can now use this Button just like a normal Button.  Hope that helped.  Here is the code you should have if you've followed everything I said.

  Public Class ExtendedButton
      Inherits Button
  
      Private m_Field1 As String = ""
  
      Public Property Field1() As String
          Get
              Return m_Field1
          End Get
          Set(ByVal value As String)
              m_Field1 = value
          End Set
      End Property
  End Class

   

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