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问候;

我在正确实例化 System.Drawing.Point 实例数组，然后在 WinForms 应用程序中使用 IronPython 将点数组添加到 GDI+ GraphicsPath 实例时遇到了一些麻烦。以下代码在 SharpDevelop 3.2 和 IronPython 2.6 下正确编译或构建：

import System.Drawing
import System.Drawing.Drawing2D 
import System.Windows.Forms

from System import Array 
from System.Drawing import Pen, Point
from System.Drawing.Drawing2D import GraphicsPath, CustomLineCap
from System.Windows.Forms import *

class MainForm(Form):
    def __init__(self):
        self.InitializeComponent()

    def InitializeComponent(self):
        self.SuspendLayout()
        # 
        # MainForm
        # 
        self.ClientSize = System.Drawing.Size(284, 264)
        self.Name = "MainForm"
        self.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen
        self.Text = "GDI Lines"
        self.Paint += self.MainFormPaint
        self.ResumeLayout(False)

    def MainFormPaint(self, sender, e):
        graphicContext = e.Graphics
        bluePen = Pen(Color.Blue, 1)

        points = Array.CreateInstance(Point, 9)
        points[0] = Point(10, 10)
        points[1] = Point(15, 10)
        points[2] = Point(20, 15)
        points[3] = Point(20, 20)
        points[4] = Point(15, 25)
        points[5] = Point(10, 25)
        points[6] = Point(5, 20)
        points[7] = Point(5, 15)
        points[8] = Point(10, 10)

        graphicsPath = GraphicsPath()
        graphicsPath.AddLines(points)
        graphicContext.SmoothingMode = SmoothingMode.AntiAlias

        lineCap = CustomLineCap(nil, graphicsPath)
        lineCap.BaseInset = 0
        lineCap.WidthScale = 1
        lineCap.StrokeJoin = LineJoin.Miter

        bluePen.CustomStartCap = lineCap
        bluePen.CustomEndCap = lineCap

        graphicContext.DrawLine(bluePen, 50, 150, 200, 150)
        graphicContext.DrawLine(bluePen, 150, 50, 150, 200)

        lineCap.Dispose()
        graphicsPath.Dispose()
        bluePen.Dispose()

根据上面的代码，我希望看到两条垂直的蓝线，每条线的末端都有一个小椭圆。使用上面的当前 scipting 代码，绘制了 GDI+ 运行时错误红色 X。我错过了什么或做错了什么？此外，是否有更简单或更简洁的方法来实例化 System.Drawing.Point 值的数组？

提前感谢您的时间和帮助...

4

1 回答 1

1

平心而论，我必须说我没有“回答我自己的问题”或自己解决这个问题，但能够从 Matt Ward 和 Michael Foord 那里得到外部帮助。我最诚挚地感谢 Matt 和 Michael 所付出的时间、帮助和耐心，我非常感谢他们回复他们的更正。

使 MainForm.py 脚本无法运行的主要问题是我遗漏了从 System.Drawing 命名空间导入 Color 类，以及从 System.Drawing.Drawing2D 命名空间导入 SmoothingMode 和 LineJoin 枚举。尽管我的脚本没有直接实例化任何其他枚举或类，但它们仍然必须由 .NET DLR 从它们各自的程序集中加载和引用，以使它们在我的脚本中可访问和可用。（注意：再次感谢马特向我指出这一点；如果解释中有任何错误，它们是我的，而不是马特的。）

GDI+ Point 实例的原始 Array 实例化是正确的，但更简洁的方法显示在下面的更正脚本中。（注意：再次感谢 Michael 指出 Array 实例化的替代方案。）

更正且有效的 MainForm.py 脚本如下：

import System.Drawing
import System.Drawing.Drawing2D 
import System.Windows.Forms

from System import Array 
from System.Drawing import Pen, Point, Color
from System.Drawing.Drawing2D import GraphicsPath, CustomLineCap, SmoothingMode, LineJoin
from System.Windows.Forms import *

class MainForm(Form):
    def __init__(self):
        self.InitializeComponent()

    def InitializeComponent(self):
        self.SuspendLayout()
        # 
        # MainForm
        # 
        self.ClientSize = System.Drawing.Size(284, 264)
        self.Name = "MainForm"
        self.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen
        self.Text = "GDI+ CustomLineCaps"
        self.Paint += self.MainFormPaint
        self.ResumeLayout(False)

    def MainFormPaint(self, sender, e):
        graphics = e.Graphics
        bluePen = Pen(Color.Blue, 1)

        points = Array[Point] \
        ((Point(10, 10), Point(15, 10), Point(20, 15), \
          Point(20, 20), Point(15, 25), Point(10, 25), \
          Point(5, 20),  Point(5, 15),  Point(10, 10)))

        graphicsPath = GraphicsPath()
        graphicsPath.AddLines(points)
        graphics.SmoothingMode = SmoothingMode.AntiAlias 

        lineCap = CustomLineCap(None, graphicsPath)
        lineCap.BaseInset = 0
        lineCap.WidthScale = 1
        lineCap.StrokeJoin = LineJoin.Miter 

        bluePen.CustomStartCap = lineCap
        bluePen.CustomEndCap = lineCap

        graphics.DrawLine(bluePen, 50, 150, 200, 150)
        graphics.DrawLine(bluePen, 150, 50, 150, 200)

        lineCap.Dispose()
        graphicsPath.Dispose()
        bluePen.Dispose()
于 2010-06-20T23:28:11.397 回答