完美Excel

   1: Imports System

   2: Imports System.Windows

   3: Imports System.Windows.Controls

   4:  

   5: Namespace CustomPanel

   6:     Public Class RibbonPanel

   7:      Inherits Panel

   8:         Protected Overrides Function MeasureOverride(ByVal availableSize As Size) As Size

   9:             If Children.Count < 1 Then

  10:                  Return New Size(0, 0)

  11:             End If

  12:  

  13:             ' Ask the first child for its desired size, given unlimited space

  14:             Dim firstChild As UIElement =  Children(0) 

  15:             firstChild.Measure(New Size(Double.PositiveInfinity,Double.PositiveInfinity))

  16:  

  17:             ' If there's only one child, this panel would like to be the exact same size

  18:             If Children.Count < 2 Then

  19:                  Return firstChild.DesiredSize

  20:             End If

  21:  

  22:             ' If not, calculate the desired width based on all children

  23:             Dim numRows As Double =  Math.Ceiling((Children.Count - 1) / 3d) 

  24:             Dim maxWidthForEachRemainingChild As Double =  0 

  25:  

  26:             Dim i As Integer

  27:             For  i = 1 To  Children.Count- 1  Step  i + 1

  28:                 ' Ask each child for its desired size, given unlimited space

  29:                 Dim child As UIElement =  Children(i) 

  30:                 child.Measure(New Size(Double.PositiveInfinity,Double.PositiveInfinity))

  31:  

  32:                 ' Keep track of the maximum width

  33:                 maxWidthForEachRemainingChild = Math.Max(child.DesiredSize.Width, maxWidthForEachRemainingChild)

  34:             Next

  35:  

  36:             Return New Size(

  37:                 firstChild.DesiredSize.Width + maxWidthForEachRemainingChild * numRows, ' total width

  38:                 Dim ' height = desired height of the first child As firstChild.DesiredSize.Height)

  39:         End Function

  40:  

  41:         Protected Overrides Function ArrangeOverride(ByVal finalSize As Size) As Size

  42:             If Children.Count < 1 Then

  43:                  Return finalSize

  44:             End If

  45:  

  46:             ' Give the first child its desired width but the height of the panel

  47:             Dim firstChild As UIElement =  Children(0) 

  48:             Dim childOrigin As Point =  New Point(0,0) 

  49:             Dim firstChildSize As Size =  New Size(firstChild.DesiredSize.Width,finalSize.Height) 

  50:             firstChild.Arrange(New Rect(childOrigin,firstChildSize))

  51:  

  52:             If Children.Count < 2 Then

  53:                  Return finalSize

  54:             End If

  55:  

  56:             ' Determine the size for all the remaining children

  57:             Dim numRows As Double =  Math.Ceiling((Children.Count - 1) / 3d) 

  58:             Dim childSize As Size =  New Size((finalSize.Width - firstChildSize.Width) / numRows,finalSize.Height / 3) 

  59:             childOrigin.X += firstChildSize.Width

  60:  

  61:             Dim i As Integer

  62:             For  i = 1 To  Children.Count- 1  Step  i + 1

  63:                 Dim child As UIElement =  Children(i) 

  64:                 child.Arrange(New Rect(childOrigin,childSize))

  65:  

  66:                 If i % 3 = 0 Then

  67:                     ' Start a new column

  68:                     childOrigin.X += childSize.Width

  69:                     childOrigin.Y = 0

  70:                 Else 

  71:                     childOrigin.Y += childSize.Height

  72:                 End If

  73:             Next

  74:  

  75:             ' Fill all the space given

  76:             Return finalSize

  77:         End Function

  78:     End Class

  79: End Namespace