用GDI+划直线

下面是代码，很容易看懂的，没有必要进行解释了吧。:)

 

using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using System.Windows.Forms;


    public class Line : System.Windows.Forms.UserControl
    ...{
        /**//// <summary> 
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.Container components = null;

        public Line()
        ...{
            // This call is required by the Windows.Forms Form Designer.
            InitializeComponent();

            SetStyle(ControlStyles.AllPaintingInWmPaint | ControlStyles.UserPaint | ControlStyles.FixedHeight | ControlStyles.FixedWidth | ControlStyles.ResizeRedraw, true);
            SetStyle(ControlStyles.Selectable, false);
            TabStop = false;
        }

        /**//// <summary> 
        /// Clean up any resources being used.
        /// </summary>
        protected override void Dispose(bool disposing)
        ...{
            if (disposing)
            ...{
                if (components != null)
                ...{
                    components.Dispose();
                }
            }
            base.Dispose(disposing);
        }

        Component Designer generated code#region Component Designer generated code
        /**//// <summary> 
        /// Required method for Designer support - do not modify 
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        ...{
            // 
            // Line
            // 
            this.Name = "Line";
            this.Size = new System.Drawing.Size(140, 140);

        }
        #endregion

        protected override void OnPaint(PaintEventArgs e)
        ...{
            base.OnPaint(e);

            int x1, x2, x3, x4, y1, y2, y3, y4;
            if (LineStyle == LineStyle.Horizontal)
            ...{
                x1 = 0;
                y1 = 0;
                x2 = ClientRectangle.Width;
                y2 = 0;

                x3 = 0;
                y3 = 1;
                x4 = ClientRectangle.Width;
                y4 = 1;
            }
            else //if (LineStyle == LineStyle.Vertical)
            ...{
                x1 = 0;
                y1 = 0;
                x2 = 0;
                y2 = ClientRectangle.Height;

                x3 = 1;
                y3 = 0;
                x4 = 1;
                y4 = ClientRectangle.Height;
            }

            using (Pen p = new Pen(m_FirstColor, 1))
            ...{
                p.DashStyle = mDashStyle;
                e.Graphics.DrawLine(p, x1, y1, x2, y2);
            }
            using (Pen p = new Pen(m_SecondColor, 1))
            ...{
                p.DashStyle = mDashStyle;
                e.Graphics.DrawLine(p, x3, y3, x4, y4);
            }
        }

        private System.Drawing.Drawing2D.DashStyle mDashStyle = System.Drawing.Drawing2D.DashStyle.Solid;
        public System.Drawing.Drawing2D.DashStyle DashStyle
        ...{
            get ...{ return mDashStyle; }
            set ...{ mDashStyle = value; Invalidate(); }
        }

        private Color m_FirstColor = Color.FromKnownColor(KnownColor.ControlDark);
        public Color FirstColor
        ...{
            get ...{ return m_FirstColor; }
            set ...{ m_FirstColor = value; Invalidate(); }
        }

        private Color m_SecondColor = Color.FromKnownColor(KnownColor.ControlLightLight);
        public Color SecondColor
        ...{
            get ...{ return m_SecondColor; }
            set ...{ m_SecondColor = value; Invalidate(); }
        }

        private LineStyle m_LineStyle = LineStyle.Horizontal;
        public LineStyle LineStyle
        ...{
            get ...{ return m_LineStyle; }
            set
            ...{
                m_LineStyle = value;
                Size = new Size(Height, Width);
                Invalidate();
            }
        }

        protected override void OnSizeChanged(EventArgs e)
        ...{
            base.OnSizeChanged(e);

            ChangeControlSize();
        }

        private void ChangeControlSize()
        ...{
            if (LineStyle == LineStyle.Horizontal)
                Height = 2;
            else if (LineStyle == LineStyle.Vertical)
                Width = 2;
        }
    }

    public enum LineStyle
    ...{
        Horizontal = 1,
        Vertical = 2
    }