Level mit MIN-MAX Steuerelement

Für die Visualisierung von Meß und Regelaufgaben bietet .NET nichts berauschendes an Steuerelementen. Deshalb wird dazu meistens LabView verwendet.
Leider ist es relativ teuer. Deshalb habe ich begonnen Steuerelemente selber zu erstellen. Als erstes einen vertikalen Balken,
der einen bestimmten Wert als Balkenlänge darstellen kann. Es sind auch negative Werte zulässig.
Zusätzlich wird ein MIN und MAX-Wert durch eine Markierung und den Wert gehalten. Geschrieben wurde der Code mit dem kostenlosen SharpDevelop
Flash is required!
'
Option Strict On
Imports System.ComponentModel
Imports System.Math
 
Public Partial Class LevelMeter
	Inherits System.Windows.Forms.UserControl
 
	Dim sglValue As Single = 0
	dim intValue as integer
	Dim sglMax As Single = 100
	Dim sglMin As Single = 0
	dim intZeroValue as integer
 
	Dim intStoreMax As Integer
	dim sglStoreMax as single
	Dim intStoreMin As Integer
	Dim sglStoreMin As Single
 
	dim bolReset as boolean
 
	Dim msngBorderWidth As Single = 1.0!
 
	Dim rctMinMarker As Rectangle
	Dim rctMaxMarker As Rectangle
	Dim rctLevelBack As Rectangle
	Dim rctLevel As Rectangle
	dim intDecimals as integer
 
	Dim intMarginTop As Integer = 8
	Dim intMarginLeft As Integer = 8
	Dim intMarginBottom As Integer = 8
	Dim intWidthLevel As Integer = 13
	Dim intMarkerHeight As Integer = 6
 
	dim colLevelBackground as Color = color.lightgray
	Dim colLevel As Color = color.limeGreen
	Dim colMinMarker As Color = color.Green
	dim colMaxMarker as Color = color.red
	Dim colMinMarkertextBox As Color = color.forestgreen
	Dim colMaxMarkertextBox As Color = color.red
	Dim colMarkertext As Color = color.white
 
    Dim penDrawingPen As New System.Drawing.Pen(System.Drawing.Color.Black, msngBorderWidth)
	Dim penDrawingBrush As New System.Drawing.solidbrush(System.Drawing.Color.lightgray)
 	Dim drawFont As New Font("Arial", 8)
    Dim grfGraphics As System.Drawing.Graphics	
 
	Public Sub New()
		Me.Size = New Size(200, 60)
        Me.SetStyle(ControlStyles.DoubleBuffer _
     	Or ControlStyles.UserPaint _
     	Or ControlStyles.AllPaintingInWmPaint, _
     	True)
        intZeroValue = CInt((Me.Height - intMarginTop - intMarginBottom)/(sglMax - sglMin)* (-sglMin))
        Me.UpdateStyles()
	End Sub
 
	Public Property value() as single
    	Get
        	return sglValue
    	End Get
    	Set(ByVal Value As Single)
			setValues(csng(round(value,intdecimals)))
    	End Set
	End Property
		Public Property Decimals() as integer
    	Get
        	return intDecimals
    	End Get
    	Set(ByVal Value As integer)
			if intdecimals >= 0 and intdecimals < 5 then intDecimals = value
    	End Set
	End Property
	Public Property Min() as single
    	Get
        	return sglMin
    	End Get
    	Set(ByVal Value As single)
            	If sglMin < sglMax Then
            		sglMin = value
            		setvalues(sglValue)
            		resetmarkers()
            	end if
    	End Set
	End Property
	Public Property Max() as single
    	Get
        	return sglMax
    	End Get
    	Set(ByVal Value As single)
            	if sglMax > sglMin then
            		sglMax = value
            		setvalues(sglValue)
            		resetmarkers()
            	end if
    	End Set
	End Property
 
	Public Property BorderWidth() As Single
	    Get
	        Return msngBorderWidth
	    End Get
	    Set(ByVal Value As Single)
	        If msngBorderWidth <> Value Then
	            msngBorderWidth = Value
	            Me.Invalidate()
	        End If
	    End Set
	End Property
 
	Public Property resetMinMax() As Boolean
		Get
			return bolReset
		End Get
		Set(ByVal value As Boolean)
			If value = true Then
				resetMarkers()
			End If
		End Set
	End Property
	Public Property colorLevel() as color
    	Get
        	return colLevel
    	End Get
    	Set(ByVal Value As color)
			colLevel = value
			Me.Invalidate()
    	End Set
	End Property
	Public Property colorLevelBackground() as color
    	Get
        	return colLevelBackground
    	End Get
    	Set(ByVal Value As color)
			colLevelBackground = value
			Me.Invalidate()
    	End Set
	End Property
	Public Property colorMinMarker() as color
    	Get
        	return colMinMarker
    	End Get
    	Set(ByVal Value As color)
			colMinMarker = value
			Me.Invalidate()
    	End Set
	End Property
	Public Property colorMaxMarker() as color
    	Get
        	return colMaxMarker
    	End Get
    	Set(ByVal Value As color)
			colMaxMarker = value
			Me.Invalidate()
    	End Set
	End Property
	Public Property colorMinMarkerTextBox() as color
    	Get
        	return colMinMarkerTextBox
    	End Get
    	Set(ByVal Value As color)
			colMinMarkerTextBox = value
			Me.Invalidate()
    	End Set
	End Property
	Public Property colorMaxMarkerTextBox() as color
    	Get
        	return colMaxMarkerTextBox
    	End Get
    	Set(ByVal Value As color)
			colMaxMarkerTextBox = value
			Me.Invalidate()
    	End Set
	End Property
	Public Property colorMarkerText() as color
    	Get
        	return colMarkerText
    	End Get
    	Set(ByVal Value As color)
			colMarkerText = value
		    Me.Invalidate()
    	End Set
	End Property
 
	Private Sub LevelMeter_Paint(ByVal sender As Object, ByVal pe As System.Windows.Forms.PaintEventArgs) Handles Me.Paint
 
	    dim msr as sizeF
	    grfGraphics = pe.Graphics
 
	    'Draw Level Background
	    penDrawingBrush.Color = colLevelBackground
	    rctLevelBack.X = intMarginLeft + 3
	    rctLevelBack.Y = intMarginTop
	    rctLevelBack.Height = Me.Height - intMarginTop - intMarginBottom
	    rctLevelBack.Width = intWidthLevel - 6
	    grfGraphics.fillRectangle(penDrawingBrush, rctLevelBack)
 
	    'Draw Level
	    penDrawingBrush.Color = colLevel
	    rctLevel.X = intMarginLeft + 3
	    If intValue < intZeroValue Then 'liegt der Nullpunkt im Skalenbereich?
	    	rctLevel.Y = Me.Height - intZeroValue - intMarginBottom
	    	rctLevel.Height = -intValue + intZeroValue
	    Else
	    	rctLevel.Y = Me.Height - intMarginBottom - intValue
	    	rctLevel.Height = intValue - intZeroValue
	    end if
 
	    rctLevel.Width = intWidthLevel - 6
	    grfGraphics.fillRectangle(penDrawingBrush, rctLevel)
		'Draw Zeroline
	    if intzerovalue <> 0 then grfGraphics.DrawLine(penDrawingPen,intMarginleft -3,Me.Height - intZeroValue - intMarginBottom,intMarginleft + intWidthLevel + 3,Me.Height - intZeroValue - intMarginBottom)
 
	    'Draw Max Marker
	    penDrawingBrush.Color = colMaxMarker
	    rctMaxMarker.X = intMarginLeft
	    rctMaxMarker.Y = Me.Height - intStoreMax - intMarginBottom - 3
	    rctMaxMarker.Width = intWidthLevel
	    rctMaxMarker.Height = intMarkerHeight
	    grfGraphics.fillEllipse(penDrawingBrush, rctMaxMarker)
 
	    'Draw Min Marker
	    penDrawingBrush.Color = colMinMarker
	    rctMinMarker.X = intMarginLeft
	    rctMinMarker.Y = Me.Height - intStoreMin  - intMarginBottom -3
	    rctMinMarker.Width = intWidthLevel
	    rctMinMarker.Height = intMarkerHeight
	    grfGraphics.fillEllipse(penDrawingBrush, rctMinMarker)
 
	    'Draw Min Box
	    msr = grfGraphics.MeasureString(sglStoreMin.ToString, drawFont)  
	    penDrawingBrush.Color = colMinMarkertextBox
	    grfGraphics.fillRectangle(penDrawingBrush,intMarginleft + intWidthLevel + 3,Me.Height - intStoreMin - intMarginBottom - cint(msr.Height/2), msr.width,msr.height)
	    penDrawingBrush.Color = colMarkertext
	    grfGraphics.DrawString(sglStoreMin.ToString,drawFont,penDrawingBrush,intMarginleft + intWidthLevel + 3,Me.Height - intStoreMin - intMarginBottom - cint(msr.Height/2))
 
	    'Draw Max Box
	    msr = grfGraphics.MeasureString(sglStoreMax.ToString, drawFont)  
	    penDrawingBrush.Color = colMaxMarkertextBox
	    grfGraphics.fillRectangle(penDrawingBrush,intMarginleft + intWidthLevel + 3,Me.Height - intStoreMax - intMarginBottom - cint(msr.height/2), msr.width,msr.height)
	    penDrawingBrush.Color = colMarkertext
	    grfGraphics.DrawString(sglStoreMax.ToString,drawFont,penDrawingBrush, intMarginleft + intWidthLevel + 3,Me.Height - intStoreMax - intMarginBottom - cint(msr.height/2))
	End Sub
	Private Sub Level_Resize(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Resize
	    setvalues(sglValue)
	    resetmarkers()
	    Me.Invalidate()
	End Sub
 
	Private Sub setValues(byval value as single)
		    If value < sglmin Then
    			sglvalue = sglmin
    		ElseIf value > sglmax Then
    			sglvalue = sglmax
    		End If
    			sglValue = value
    			intValue = CInt((Me.Height - intMarginTop - intMarginBottom)/(sglMax - sglMin)*(sglValue- sglMin))
	    		If sglValue > sglStoreMax Then sglStoreMax = sglValue
	    		If sglValue < sglStoreMin Then sglStoreMin = sglValue
	    		If intValue > (Me.Height - intMarginTop - intMarginBottom) Then intValue = (Me.Height - intMarginTop - intMarginBottom)
	    		if intValue < 0 then intValue = 0
	    		If intValue > intStoreMax Then intStoreMax = intValue
	    		If intValue < intStoreMin Then intStoreMin = intValue
    			Me.Invalidate()
	End Sub
	Private Sub ResetMarkers()
				sglStoreMax = sglValue
				sglStoreMin = sglValue
				intStoreMax = intValue
				intStoreMin = intValue
				bolReset = False
				'Der Nullpunkt des Balkens von unten in Pixel.
				intZeroValue = CInt((Me.Height - intMarginTop - intMarginBottom)/(sglMax - sglMin)* (-sglMin))
				me.Invalidate()
	End Sub
End Class