VB中实时曲线的显示

1、VB 中实时曲线的显示在使用 VB 开发工控软件 (HMI) 时，经常需要对工艺参数进行趋势曲线的显示，这通常 需要使用控件来实现， 自然有第三方提供的控件， 但那是需要付费的， 并且有的使用情况并 不理想，自己开发的话又差强人意， 这里提供一个实时曲线显示的程序，给大家以启发。通 过对程序的修改，可以很方便的应用到实际工程中去。首先建立一个名为 DrawLine 的类模块，代码如下：Public HorzSplits As LongPublic VertSplits As LongPublic Max As SinglePrivate ValueArray() As Single '

2、 存放数据的数组Private LineColor As LongPrivate GridColor As LongPrivate ShowGrid As BooleanPrivate pBox As PictureBoxPrivate pBoxHeight As LongPrivate pBoxWidth As LongPrivate MovingGrid As BooleanPrivate StartPosition As LongPrivate GridPosition As LongPublic Enum DrawLineTypeTYPE_LINE = 0 TYPE_POINT = 1

3、 End EnumPublic LineType As DrawLineType ' 划线的类型：线或点Const const_tolerance = 0.0001 ' 误差Public Function InitDrawLine(pB As PictureBox, LColor As Long, SGrid As Boolean, Optional GColor As Variant, Optional MoveGrid As V ariant) pB.ScaleMode = vbPixelsLineColor = Lcolor ShowGrid = Sgrid pBoxHe

4、ight = pB.ScaleHeight pBoxWidth = pB.ScaleWidthIf IsMissing(GColor) ThenGridColor = RGB(0, 130, 0) ' 默认值绿色Else:GridColor = GcolorEnd IfIf IsMissing(MoveGrid) ThenMovingGrid = False ' 如果用户未定 MoveGrid 值则默认为关。Else:MovingGrid = MoveGridEnd IfSet pBox = pB'分配数组ReDim ValueArray(pBoxWidth - 1)S

5、tartPositi on = pBoxWidth -1GridPosition = 0End FunctionPublic Sub AddValue(value As Single)Dim l As Long ' 检查 InitDrawline 是否被执行，失败则退出If pBox Is Nothing ThenExit SubEnd If'将数组所有值移动一位。For l = 1 To pBoxWidth -1ValueArray(l - 1) = ValueArray(l)NextIf Max <= 0 Then Max = 1'把新的值添加到数组的最后一个

6、元素。ValueArray(l - 1) = pBoxHeight - (value / Max) * pBoxHeight)If StartPosition >= 1 Then StartPosition = StartPosition-1GridPosition = GridPosition -1End SubPublic Sub RePaint()Dim x As SingleDim y As SingleDim l As LongIf pBox Is Nothing ThenExit SubEnd If'首先清除图片，然后画网格( 如果有的话 )，最后画线。pBox.Cl

7、sIf (ShowGrid) ThenpBox.ForeColor = GridColorIf (MovingGrid) ThenFor x = GridPosition To pBoxWidth - 1 Step (pBoxWidth - 1) / (VertSplits + 1) - const_tolerance pBox.Line (x, 0)-(x, pBoxHeight)NextElse:For x = 0 To pBoxWidth - 1 Step (pBoxWidth - 1) / (VertSplits + 1) - const_tolerance pBox.Line (x,

8、 0)-(x, pBoxHeight)NextEnd IfFor y = 0 To pBoxHeight - 1 Step (pBoxHeight - 1) / (HorzSplits + 1) - const_tolerance pBox.Line (0, y)-(pBoxWidth, y)Next'网格复位If GridPosition <= -Int(pBoxWidth - 1 / (HorzSplits + 1) Then GridPosition = 0End IfEnd IfIf StartPosition <= pBoxWidth - 1 Then pBox.

9、ForeColor = LineColor Select Case DiagramType Case TYPE_LINEFor l = StartPositi on + 1 To pBoxWidth -2 pBox.Line (l, ValueArray(l)-(l + 1, ValueArray(l + 1) NextCase TYPE_POINTFor l = StartPositi on + 1 To pBoxWidth -2 pBox.PSet (l + 1, ValueArray(l + 1) NextEnd SelectEnd IfEnd Sub然后在窗体中添加四个 picture

10、box 控件，添加代码如下：Public LDraw1 As New DrawLinePublic LDraw2 As New DrawLinePublic PDraw1 As New DrawLinePublic PDraw2 As New DrawLinePublic tancounter As SinglePrivate Sub Command1_Click()'.InitDrawLine picturebox, lcolor, sgrid, gcolor, movegrid 'picturebox = 要划线的 picturebox'lcolor = 线的颜色&

11、#39;sgrid = 是否使用网格'gcolor = optional 网格颜色 (默认值为绿色 )'movegrid = optional 网格是否移动 (默认值不移动 )With LDraw1.InitDrawLine Picture_line, vbWhite, True.Max = 10 .HorzSplits = 9 .VertSplits = 9.LineType = TYPE_LINE.RePaintEnd WithWith PDraw1.InitDrawLine Picture_point, vbRed, True .Max = 20.HorzSplits =

12、 9.VertSplits = 9 .LineType = TYPE_POINT .RePaint End With With LDraw2 .InitDrawLine Picture_line2, vbGreen, True, , True .Max = 5 .HorzSplits = 9 .VertSplits = 9.LineType = TYPE_LINE .RePaint End With With PDraw2.InitDrawLine Picture_point2, vbYellow, True, RGB(100, 100, 0), True .Max = 10.HorzSpli

13、ts = 9 .VertSplits = 9 .LineType = TYPE_POINT .RePaintEnd With End Sub Private Sub Picture_line_Paint() LDraw1.RePaint End SubPrivate Sub Picture_line2_Click() LDraw2.RePaintEnd SubPrivate Sub Picture_point_Paint() PDraw1.RePaintEnd SubPrivate Sub Picture_point2_Click() PDraw1.RePaintEnd SubPrivate Sub Timer1_Timer()Dim value As Single tancounter = tancounter + 0.1 value = Sin(tancounter) + 2 LDraw1.AddValue value LDra