Windows Mobile引路蜂地图开发示例：二维图形库

Windows Mobile引路蜂地图开发包带有一个高效二维图形库，这是因为诸如LineCap, LineJoin, Brush, TextBrush, Path 等方法在Windows .Net Compact Framework 平台上不支持。Windows Mobile引路蜂地图开发包中的二维图形库弥补了这些缺陷，它提供了在桌面平台System.Drawing.Drawing2D中相应功能。

引路蜂地图开发包使用了这个图形库来绘制路径以及矢量地图。

基本知识

二维图形库使用类Graphics2D作为画板，内部画板实际为一个整数型二维数组。这种设计可以实现平台无关性。在绘制好图形后，最终是要在屏幕上显示的。在Windows Mobile平台上没有提供直接绘制整数型二维数组的方法。下面是在Windows Mobile绘制数型二维数组的方法。数组中每个元素为一个32位整数，格式为 AAAARRRRGGGGBBBB，分别代表透明度，红色，绿色，蓝色。

/// <summary>/// Graphics 2D Object/// </summary>private readonly Graphics2D graphics2D;  /// <summary>/// screen width/// </summary>private readonly int screenWidth;  /// <summary>/// screen Height/// </summary>private readonly int screenHeight;.....screenWidth = Width;screenHeight = Height;graphics2D = new Graphics2D(screenWidth, screenHeight);private void MainForm_Paint(object sender, PaintEventArgs e){    DrawRGB(e.Graphics, graphics2D.Argb, 0, 0, screenWidth, screenHeight);} //////////////////////////////////////////////////////////////////////////////--------------------------------- REVISIONS ------------------------------// Date       Name                 Tracking #         Description// ---------  -------------------  -------------      ----------------------// 24SEP2010  James Shen                               Code review/////////////////////////////////////////////////////////////////////////////// <summary>/// Draws the RGB./// </summary>/// <param name="graphics">The graphics.</param>/// <param name="rgbData">The RGB data.</param>/// <param name="x">The x.</param>/// <param name="y">The y.</param>/// <param name="w">The w.</param>/// <param name="h">The h.</param>private static void DrawRGB(Graphics graphics, int[] rgbData, int x,   int y, int w, int h){    Bitmap bmp = new Bitmap(w, h);    System.Drawing.Rectangle rect = new System.Drawing.Rectangle(0, 0, bmp.Width, bmp.Height);    BitmapData bmpData =    bmp.LockBits(rect, ImageLockMode.ReadWrite, PixelFormat.Format32bppRgb);    IntPtr ptr = bmpData.Scan0;    System.Runtime.InteropServices.Marshal.Copy(rgbData, 0, ptr, rgbData.Length);    bmp.UnlockBits(bmpData);    graphics.DrawImage(bmp, x, y);}

下面简单介绍一下图形库，功能基本和桌面平台类似。

颜色

/** * The solid (full opaque) red color in the ARGB space */Color redColor = new Color(0xffff0000, false); /** * The semi-opaque green color in the ARGB space (alpha is 0x78) */Color greenColor = new Color(0x7800ff00, true); /** * The semi-opaque blue color in the ARGB space (alpha is 0x78) */Color blueColor = new Color(0x780000ff, true);/** * The semi-opaque yellow color in the ARGB space ( alpha is 0x78) */Color yellowColor = new Color(0x78ffff00, true); /** * The dash array */int[] dashArray = { 20, 8 };graphics2D.Reset();graphics2D.Clear(Color.Black);SolidBrush brush = new SolidBrush(redColor);graphics2D.FillOval(brush, 30, 60, 80, 80);brush = new SolidBrush(greenColor);graphics2D.FillOval(brush, 60, 30, 80, 80);Pen pen = new Pen(yellowColor, 10, Pen.CapButt, Pen.JoinMiter, dashArray, 0);brush = new SolidBrush(blueColor);graphics2D.SetPenAndBrush(pen, brush);graphics2D.FillOval(null, 90, 60, 80, 80);graphics2D.DrawOval(null, 90, 60, 80, 80);Invalidate();

线段接头(LineCap)

Color blackColor = new Color(0x000000);Color whiteColor = new Color(0xffffff);graphics2D.Reset();graphics2D.Clear(Color.White); Pen pen = new Pen(blackColor, 20, Pen.CapButt, Pen.JoinMiter);graphics2D.DrawLine(pen, 40, 60, 140, 60);pen = new Pen(whiteColor, 1);graphics2D.DrawLine(pen, 40, 60, 140, 60); pen = new Pen(blackColor, 20, Pen.CapRound, Pen.JoinMiter);graphics2D.DrawLine(pen, 40, 100, 140, 100);pen = new Pen(whiteColor, 1);graphics2D.DrawLine(pen, 40, 100, 140, 100); pen = new Pen(blackColor, 20, Pen.CapSquare, Pen.JoinMiter);graphics2D.DrawLine(pen, 40, 140, 140, 140);pen = new Pen(whiteColor, 1);graphics2D.DrawLine(pen, 40, 140, 140, 140);Invalidate();

梨子

 最后一个例子是利用各种几何图形通过“加”，“减”，“并”操作组成一个梨子图形。

 

Ellipse circle, oval, leaf, stem;Area circ, ov, leaf1, leaf2, st1, st2;circle = new Ellipse();oval = new Ellipse();leaf = new Ellipse();stem = new Ellipse();circ = new Area(circle);ov = new Area(oval);leaf1 = new Area(leaf);leaf2 = new Area(leaf);st1 = new Area(stem);st2 = new Area(stem);graphics2D.Reset();graphics2D.Clear(Color.White);int w = screenWidth;int h = screenHeight;int ew = w / 2;int eh = h / 2;SolidBrush brush = new SolidBrush(Color.Green);graphics2D.DefaultBrush = brush;// Creates the first leaf by filling the intersection of two Area//objects created from an ellipse.leaf.SetFrame(ew - 16, eh - 29, 15, 15);leaf1 = new Area(leaf);leaf.SetFrame(ew - 14, eh - 47, 30, 30);leaf2 = new Area(leaf);leaf1.Intersect(leaf2);graphics2D.Fill(null, leaf1); // Creates the second leaf.leaf.SetFrame(ew + 1, eh - 29, 15, 15);leaf1 = new Area(leaf);leaf2.Intersect(leaf1);graphics2D.Fill(null, leaf2); brush = new SolidBrush(Color.Black);graphics2D.DefaultBrush = brush; // Creates the stem by filling the Area resulting from the//subtraction of two Area objects created from an ellipse.stem.SetFrame(ew, eh - 42, 40, 40);st1 = new Area(stem);stem.SetFrame(ew + 3, eh - 47, 50, 50);st2 = new Area(stem);st1.Subtract(st2);graphics2D.Fill(null, st1); brush = new SolidBrush(Color.Yellow);graphics2D.DefaultBrush = brush; // Creates the pear itself by filling the Area resulting from the//union of two Area objects created by two different ellipses.circle.SetFrame(ew - 25, eh, 50, 50);oval.SetFrame(ew - 19, eh - 20, 40, 70);circ = new Area(circle);ov = new Area(oval);circ.Add(ov);graphics2D.Fill(null, circ);Invalidate();

Windows Mobile引路蜂地图开发包Ver2.1下载