lserp_cs_5.0/插件库/Lskj.PubUtils/GraphicsText.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
using System.Drawing.Drawing2D;

namespace Lskj.PubUtils
{
    public class GraphicsText
    {
        private Graphics _graphics;

        public GraphicsText()
        {

        }

        public Graphics Graphics
        {
            get { return _graphics; }
            set { _graphics = value; }
        }

        /// <summary>  
        /// 绘制根据矩形旋转文本  
        /// </summary>  
        /// <param name="s">文本</param>  
        /// <param name="font">字体</param>  
        /// <param name="brush">填充</param>  
        /// <param name="layoutRectangle">局部矩形</param>  
        /// <param name="format">布局方式</param>  
        /// <param name="angle">角度</param>  
        public void DrawString(string s, Font font, Brush brush, RectangleF layoutRectangle, StringFormat format, float angle)
        {
            // 求取字符串大小  
            SizeF size = _graphics.MeasureString(s, font);

            // 根据旋转角度，求取旋转后字符串大小  
            SizeF sizeRotate = ConvertSize(size, angle);

            // 根据旋转后尺寸、布局矩形、布局方式计算文本旋转点  
            PointF rotatePt = GetRotatePoint(sizeRotate, layoutRectangle, format);

            // 重设布局方式都为Center  
            StringFormat newFormat = new StringFormat(format);
            newFormat.Alignment = StringAlignment.Center;
            newFormat.LineAlignment = StringAlignment.Center;

            // 绘制旋转后文本  
            DrawString(s, font, brush, rotatePt, newFormat, angle);
        }

        /// <summary>  
        /// 绘制根据点旋转文本，一般旋转点给定位文本包围盒中心点  
        /// </summary>  
        /// <param name="s">文本</param>  
        /// <param name="font">字体</param>  
        /// <param name="brush">填充</param>  
        /// <param name="point">旋转点</param>  
        /// <param name="format">布局方式</param>  
        /// <param name="angle">角度</param>  
        public void DrawString(string s, Font font, Brush brush, PointF point, StringFormat format, float angle)
        {
            // Save the matrix  
            Matrix mtxSave = _graphics.Transform;

            Matrix mtxRotate = _graphics.Transform;
            mtxRotate.RotateAt(angle, point);
            _graphics.Transform = mtxRotate;

            _graphics.DrawString(s, font, brush, point, format);

            // Reset the matrix  
            _graphics.Transform = mtxSave;
        }

        private SizeF ConvertSize(SizeF size, float angle)
        {
            Matrix matrix = new Matrix();
            matrix.Rotate(angle);

            // 旋转矩形四个顶点  
            PointF[] pts = new PointF[4];
            pts[0].X = -size.Width / 2f;
            pts[0].Y = -size.Height / 2f;
            pts[1].X = -size.Width / 2f;
            pts[1].Y = size.Height / 2f;
            pts[2].X = size.Width / 2f;
            pts[2].Y = size.Height / 2f;
            pts[3].X = size.Width / 2f;
            pts[3].Y = -size.Height / 2f;
            matrix.TransformPoints(pts);

            // 求取四个顶点的包围盒  
            float left = float.MaxValue;
            float right = float.MinValue;
            float top = float.MaxValue;
            float bottom = float.MinValue;

            foreach (PointF pt in pts)
            {
                // 求取并集  
                if (pt.X < left)
                    left = pt.X;
                if (pt.X > right)
                    right = pt.X;
                if (pt.Y < top)
                    top = pt.Y;
                if (pt.Y > bottom)
                    bottom = pt.Y;
            }

            SizeF result = new SizeF(right - left, bottom - top);
            return result;
        }

        private PointF GetRotatePoint(SizeF size, RectangleF layoutRectangle, StringFormat format)
        {
            PointF pt = new PointF();

            switch (format.Alignment)
            {
                case StringAlignment.Near:
                    pt.X = layoutRectangle.Left + size.Width / 2f;
                    break;
                case StringAlignment.Center:
                    pt.X = (layoutRectangle.Left + layoutRectangle.Right) / 2f;
                    break;
                case StringAlignment.Far:
                    pt.X = layoutRectangle.Right - size.Width / 2f;
                    break;
                default:
                    break;
            }

            switch (format.LineAlignment)
            {
                case StringAlignment.Near:
                    pt.Y = layoutRectangle.Top + size.Height / 2f;
                    break;
                case StringAlignment.Center:
                    pt.Y = (layoutRectangle.Top + layoutRectangle.Bottom) / 2f;
                    break;
                case StringAlignment.Far:
                    pt.Y = layoutRectangle.Bottom - size.Height / 2f;
                    break;
                default:
                    break;
            }

            return pt;
        }
    }
}