VB.NET GraphicsPathIterator.NextPathType方法代码示例

Public Sub NextPathTypeExample(ByVal e As PaintEventArgs)

    ' Create the GraphicsPath.
    Dim myPath As New GraphicsPath
    Dim myPoints As Point() = {New Point(20, 20), _
    New Point(120, 120), New Point(20, 120), New Point(20, 20)}
    Dim myRect As New Rectangle(120, 120, 100, 100)

    ' Add 3 lines, a rectangle, and an ellipse.
    myPath.AddLines(myPoints)
    myPath.AddRectangle(myRect)
    myPath.AddEllipse(220, 220, 100, 100)

    ' List all of the path points to the screen.
    ListPathPointsHelper(e, myPath, Nothing, 20, 1)

    ' Create a GraphicsPathIterator.
    Dim myPathIterator As New GraphicsPathIterator(myPath)

    ' Rewind the Iterator.
    myPathIterator.Rewind()

    ' Iterate the subpaths and types, and list the results
    ' to the screen.
    Dim j As Integer = 20
    Dim i As Integer
    Dim mySubPaths, subPathStartIndex, subPathEndIndex As Integer
    Dim IsClosed As [Boolean]
    Dim subPathPointType As Byte
    Dim pointTypeStartIndex, pointTypeEndIndex, _
    numPointsFound As Integer
    Dim myFont As New Font("Arial", 8)
    Dim myBrush As New SolidBrush(Color.Black)
    j = 20
    For i = 0 To 2
        mySubPaths = myPathIterator.NextSubpath(subPathStartIndex, _
            subPathEndIndex, IsClosed)
        numPointsFound = myPathIterator.NextPathType(subPathPointType, _
            pointTypeStartIndex, pointTypeEndIndex)
        e.Graphics.DrawString("SubPath: " & i & "  Points Found: " & _
            numPointsFound.ToString() & "  Type of Points: " & _
        subPathPointType.ToString(), myFont, myBrush, 200, j)
        j += 20
    Next i

    ' List the total number of path points to the screen.
    ListPathPointsHelper(e, myPath, myPathIterator, 200, 2)
End Sub

' This is a helper function used by NextPathTypeExample.
Public Sub ListPathPointsHelper(ByVal e As PaintEventArgs, _
ByVal myPath As GraphicsPath, ByVal myPathIterator As GraphicsPathIterator, _
ByVal xOffset As Integer, ByVal listType As Integer)

    ' Get the total number of points for the path,
    ' and the arrays of the points and types.
    Dim myPathPointCount As Integer = myPath.PointCount
    Dim myPathPoints As PointF() = myPath.PathPoints
    Dim myPathTypes As Byte() = myPath.PathTypes

    ' Set up variables for drawing the points to the screen.
    Dim i As Integer
    Dim j As Single = 20
    Dim myFont As New Font("Arial", 8)
    Dim myBrush As New SolidBrush(Color.Black)
    If listType = 1 Then
        ' List all the path points to the screen.

        ' Draw the set of path points and types to the screen.
        For i = 0 To myPathPointCount - 1
            e.Graphics.DrawString(myPathPoints(i).X.ToString() + ", " + _
                myPathPoints(i).Y.ToString() + ", " + _
            myPathTypes(i).ToString(), myFont, myBrush, xOffset, j)
            j += 20
        Next i
    Else
        If listType = 2 Then
            ' Display the total number of path points.

            ' Draw the total number of points to the screen.
            Dim myPathTotalPoints As Integer = myPathIterator.Count
            e.Graphics.DrawString("Total Points = " + _
                myPathTotalPoints.ToString(), myFont, myBrush, xOffset, _
                100)
        Else
            e.Graphics.DrawString("Wrong or no list type argument.", _
                myFont, myBrush, xOffset, 200)
        End If
    End If
End Sub