[RESOLVED] Graphics Rectangle

I am trying to have different types of rectangles. I thought something like this would work, but Rectangle is not a class.

Code:

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    Public Class xRectangle
        Inherits Rectangle
    End Class

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What I wanted this for was to remove a selection rectangle from an existing drawing. I have all of the objects to draw stored in a list and I am trying to remove the selection rectangle without removing the object it is covering. Hope this makes a little sense.

System.Drawing.Rectangle is a structure and you can't inherit structures, plain and simple. If you need a class that you can inherit then define your own base class and then inherit that. That base class can either wrap a Rectangle structure or define its own functionality from scratch.

Thanks jmc! I have been working on this since posting the question and as usual your advice is great. (BTW - I (borrowed, copied, used,...) some code you had written for a line that computed the rectangle for the line.)

Does this seem like the right direction?

Code:

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Public MustInherit Class Shape
    Private _x, _y, _w, _h As Integer
    Private _spt, _ept As Point
    Private _r As Rectangle

    Public Sub New(ByVal spt As Point, ByVal ept As Point)
        'lines - thanks to jmc @ vbforums
        'define a rectangle for the line
...
    End Sub

    Public Sub New(ByVal x As Integer, ByVal y As Integer, ByVal w As Integer, ByVal h As Integer)
        'rectangle
...
    End Sub

    Public Property X() As Integer
        Get
            Return Me._x
        End Get
        Set(ByVal value As Integer)
            Me._x = value
        End Set
    End Property

    Public Property Y() As Integer
        Get
            Return Me._y
        End Get
        Set(ByVal value As Integer)
            Me._y = value
        End Set
    End Property

    Public Property Width() As Integer
        Get
            Return Me._w
        End Get
        Set(ByVal value As Integer)
            Me._w = value
        End Set
    End Property

    Public Property Height() As Integer
        Get
            Return Me._h
        End Get
        Set(ByVal value As Integer)
            Me._h = value
        End Set
    End Property

End Class





Public Class dRectangle
    Inherits Shape
    Public Sub New(ByVal X As Integer, ByVal Y As Integer, _
                  ByVal Width As Integer, ByVal Height As Integer)
        MyBase.New(X, Y, Width, Height)
    End Sub

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It seems like it is starting to come together.

Code:

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        Dim test As New dRectangle(0, 0, 10, 10)

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At a glance, yes, although there's not much point having your _x, _y, _w and _h fields as well as _r, given that a Rectangle structure contains that same information. If you're going to wrap a Rectangle structure then you don't really need your own fields.

Quote:

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Originally Posted by jmcilhinney

At a glance, yes, although there's not much point having your _x, _y, _w and _h fields as well as _r, given that a Rectangle structure contains that same information. If you're going to wrap a Rectangle structure then you don't really need your own fields.

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Good point. I can't thank you enough. Some of your other posts are slowly getting me through understanding graphics. Yesterday for the first time I actually started to believe I might know what the hell was going on. ;)