在 Xamarin.iOS (Xamarin Monotouch) 中绘制圆圈以图形方式显示进度

As I'm very new to Xamarin World and new to its controls. I would like to add Circles to Show Work Progress in my mono touch app. For showing Progress I have to mark an Arc in the circle. And if possible any one can help with me a sample code. Awaiting an answer, Thanks a lot in advance.

using System;
    using UIKit;
    using CoreGraphics;

    namespace CircleTest.Touch
    {
        public class CircleGraph : UIView
        {
            int _radius = 10;
            int _lineWidth = 10;
            nfloat _degrees = 0.0f;
            UIColor _backColor = UIColor.FromRGB(46, 60, 76);
            UIColor _frontColor = UIColor.FromRGB(234, 105, 92);
            //FromRGB (234, 105, 92);

        public CircleGraph (CGRect frame, int lineWidth, nfloat degrees)
        {
            _lineWidth = lineWidth; 
            _degrees = degrees; 
            this.Frame = new CGRect(frame.X, frame.Y, frame.Width, frame.Height);
            this.BackgroundColor = UIColor.Clear; 

        }

        public CircleGraph (CGRect frame, int lineWidth, UIColor backColor, UIColor frontColor)
        {
            _lineWidth = lineWidth;
            this.Frame = new CGRect(frame.X, frame.Y, frame.Width, frame.Height);
            this.BackgroundColor = UIColor.Clear;

        }

        public override void Draw (CoreGraphics.CGRect rect)
        {
            base.Draw (rect);

            using (CGContext g = UIGraphics.GetCurrentContext ()) {
                _radius = (int)( (this.Bounds.Width) / 3) - 8;
                DrawGraph(g, this.Bounds.GetMidX(), this.Bounds.GetMidY());
            };
        }

        public void DrawGraph(CGContext g,nfloat x0,nfloat y0) {
            g.SetLineWidth (_lineWidth);

            // Draw background circle
            CGPath path = new CGPath ();
            _backColor.SetStroke ();
            path.AddArc (x0, y0, _radius, 0, 2.0f * (float)Math.PI, true);
            g.AddPath (path);
            g.DrawPath (CGPathDrawingMode.Stroke);

            // Draw overlay circle
            var pathStatus = new CGPath ();
            _frontColor.SetStroke ();
            pathStatus.AddArc(x0, y0, _radius, 0, _degrees * (float)Math.PI, false);
            g.AddPath (pathStatus);
            g.DrawPath (CGPathDrawingMode.Stroke);
        }
    }
}

事实上这就是我真正应该做的。它对我有用

这就是它的样子。你可以像类文件一样创建它，然后简单地分配给 UIView。 如需更多参考，您可以使用此示例项目Pi Graph

[EDIT]: The Draw方法最初通过了View.Framex,y 到DrawGraph方法。这应该是View.Bounds（上面进行了修改以反映这一点）。请记住，框架 x,y 引用包含的超级视图，而边界引用当前视图。如果视图是在 0,0 添加的，那么这会起作用，但一旦你开始在 UI 上移动，它就会消失。绘制弧线时，传递给 AddArc 的 x、y 值需要引用当前视图而不是父超级视图。