使用System.Drawing绘制圆圈

我有这个代码绘制一个矩形（我试图重新制作MS Paint）

case "Rectangle": if (tempDraw != null) { tempDraw = (Bitmap)snapshot.Clone(); Graphics g = Graphics.FromImage(tempDraw); Pen myPen = new Pen(foreColor, lineWidth); g.DrawRectangle(myPen, x1, y1, x2-x1, y2-y1); myPen.Dispose(); e.Graphics.DrawImageUnscaled(tempDraw, 0, 0); g.Dispose(); } 

但是，如果我想绘制一个圆圈，会发生什么变化呢？

 g.DrawRectangle(myPen, x1, y1, x2-x1, y2-y1); 

Answer 1

请尝试使用DrawEllipse方法。

Answer 2

没有DrawCircle方法; 请改用DrawEllipse 。 我有一个静态类，其中包含绘制和填充圆圈的图形扩展方法（此处未显示）。 它们是DrawEllipse和FillEllipse包装器：

 public static class GraphicsExtensions { public static void DrawCircle(this Graphics g, Pen pen, float centerX, float centerY, float radius) { g.DrawEllipse(pen, centerX - radius, centerY - radius, radius + radius, radius + radius); } public static void FillCircle(this Graphics g, Brush brush, float centerX, float centerY, float radius) { g.FillEllipse(brush, centerX - radius, centerY - radius, radius + radius, radius + radius); } } 

你可以像这样打电话给他们：

 g.FillCircle(myBrush, center X, centerY, radius); g.DrawCircle(myPen, centerX, centerY, radius); 

Answer 3

如果要使用GDI +绘制圆，则需要使用DrawEllipse 。

这里有一个例子： http ： //www.websupergoo.com/helpig6net/source/3-examples/9-drawgdi.htm

Answer 4

你应该使用DrawEllipse ：

 // // Summary: // Draws an ellipse defined by a bounding rectangle specified by coordinates // for the upper-left corner of the rectangle, a height, and a width. // // Parameters: // pen: // System.Drawing.Pen that determines the color, width, // and style of the ellipse. // // x: // The x-coordinate of the upper-left corner of the bounding rectangle that // defines the ellipse. // // y: // The y-coordinate of the upper-left corner of the bounding rectangle that // defines the ellipse. // // width: // Width of the bounding rectangle that defines the ellipse. // // height: // Height of the bounding rectangle that defines the ellipse. // // Exceptions: // System.ArgumentNullException: // pen is null. public void DrawEllipse(Pen pen, int x, int y, int width, int height); 

Answer 5

如果你想在按钮上绘制圆圈，那么这段代码可能会被使用。 否则，如果你想在其他控件上绘制一个圆圈，只需更改控件名称和事件。 像这里调用事件按钮。 如果要在组框中绘制此圆圈，请调用Groupbox事件。 问候

  public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { this.button1.Location = new Point(108, 12); // this.Paint += new PaintEventHandler(Form1_Paint); this.button1.Paint += new PaintEventHandler(button1_Paint); } void button1_Paint(object sender, PaintEventArgs e) { Graphics g = this.button1.CreateGraphics(); Pen pen = new Pen(Color.Red); g.DrawEllipse(pen, 10, 10, 20, 20); } } 

Answer 6

使用此代码，您可以轻松绘制一个圆圈… C＃很棒，很容易我的朋友

 public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { Graphics myGraphics = base.CreateGraphics(); Pen myPen = new Pen(Color.Red); SolidBrush mySolidBrush = new SolidBrush(Color.Red); myGraphics.DrawEllipse(myPen, 50, 50, 150, 150); } } 

Answer 7

  private void DrawEllipseRectangle(PaintEventArgs e) { Pen p = new Pen(Color.Black, 3); Rectangle r = new Rectangle(100, 100, 100, 100); e.Graphics.DrawEllipse(p, r); } private void Form1_Paint(object sender, PaintEventArgs e) { DrawEllipseRectangle(e); }