Question

我正在尝试在WinForms中创建自定义ListBox控件。

我已将其子类化，设置DrawMode.OwnerDrawFixed，并覆盖OnDrawItem。我创建了一个自定义ColoredListBoxItem类，它具有处理突出显示的其他属性。

这一切都很好。我的问题是，此功能需要突出显示列表项文本中的单词。

据我所知，这并不起作用，因为高光的X坐标保持不变，与文本的实际X坐标不对应。

如何获得Point值（或Rectangle）与DrawText一起使用，以覆盖突出显示的文字？我尝试使用原始文本Rectangle与突出显示Rectangle的界限进行一些数学计算，但它没有按预期工作。

protected override void OnDrawItem(DrawItemEventArgs e) {

    ColoredListBoxItem item = this.Items[e.Index] as ColoredListBoxItem;

    e.DrawBackground();
    e.DrawFocusRectangle();

    Rectangle fullMessageRect = e.Bounds;

    // Draw the original, full text
    TextRenderer.DrawText(e.Graphics, item.Message, e.Font, 
          new Point(fullMessageRect.X, fullMessageRect.Y), 
          this.ForeColor);

    // Check if we have any text to be highlighted
    if (SomethingToHighlight(item)) {

        // Find the text to highlight, and get its area
        SizeF highlightedAreaSize = 
              e.Graphics.MeasureString(item.TextToHightlight, e.Font);

        PointF highlightAreaPoint = highlightedAreaSize.ToPointF();

        Point point = new Point(Convert.ToInt32(highlightAreaPoint.X),
             Convert.ToInt32(fullMessageRect.Y));

        TextRenderer.DrawText(e.Graphics, item.TextToHightlight, e.Font, 
             point, this.ForeColor, item.HighlightColor);

    }

}

以下是我在演示应用中看到的内容，其中输出只显示正在完成的工作，我正在尝试突出显示一个特定的单词...在这种情况下＆＃34; height＆＃34;。< / p>

不要注意实际的输出，这是一堆废话，所以我可以确切地看到系统的另一部分是如何动态调整PictureBox图像。

它认为应该突出显示的行显示两次，一次是原始格式，然后再次应用突出显示。注意突出显示的部分在Y坐标中是如何正确的，但在X中没有变化。

当我在编写突出显示的文本之前设置断点时，我在Watch窗口中看到的是：

显然，我不需要变量highlightAreaPoint，因为它与highlightedAreaSize相同。

可能这里显而易见的事情，但我现在厌倦了摆弄它！

Answer 1

我能感受到你曾经去过那里的痛苦。实际上，我想设计自己的Textbox而不是继承自Microsoft.Textbox控件，当我在线研究时，我有点沮丧地学习1000个理由，为什么一个人不能重新发明轮子以及为什么从头开始这么困难。突出选择文本是其他主要挑战之一，如从右到左，插入符号，非固定字体等。但我决定逆风而行，因为我有理由这样做，最后得到我想要的。由于我的文本选择代码是针对TextBox的，因此在处理ListBox时我必须更改它以满足您的要求。

以下是代码段：

using System;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace HowToHighlightPortionOfText
{
    public static class Helper
    {
        private static Rectangle dummy
        {
            get
            {
                return new Rectangle(0, 0, 10, 10);
            }
        }
        const uint H = 0x00000000;
        const uint V = 0x00000001;
        const uint T = 0x00000002;

        #region api functions
        [DllImport("user32.dll")]
        static extern int DrawText(IntPtr hdc, string lpStr, int nCount, ref Dimension lpRect, int wFormat);

        [DllImport("gdi32.dll")]
        public static extern IntPtr SelectObject(this IntPtr hdc, IntPtr hObject);

        [DllImport("gdi32.dll")]
        public static extern int DeleteObject(this IntPtr hObject);

        [DllImport("gdi32.dll", EntryPoint = "GdiGradientFill", ExactSpelling = true)]
        static extern bool GradientFill(IntPtr hdc, Trivertex[] pVertex,
            uint dwNumVertex, uint[] pMesh, uint dwNumMesh, uint dwMode);

        [DllImport("gdi32")]
        public static extern int SetBkMode(this IntPtr hdc, int nBkMode);

        [DllImport("gdi32.dll")]
        public static extern uint SetTextColor(this IntPtr hdc, int crColor);

        [DllImport("gdi32.dll")]
        public static extern uint SetBkColor(this IntPtr hdc, int crColor);
        #endregion

        #region public methods
        //use this function to hilight portion of listbox item text
        public static void HilightItemText(this ListBox control, int itemIndex, int startIndex, int endIndex,
             Color highlightForeColor, Color highlightBackColorStart,  Color? highlightBackColorEnd = null)
        {
            var container = control.GetItemRectangle(itemIndex);
            var text = control.GetItemText(itemIndex);

            using (Graphics g = control.CreateGraphics())
            {
                g.HighlightText(control.Font, text, container, startIndex, endIndex,
                    highlightForeColor, highlightBackColorStart, highlightBackColorEnd);

            }
        }

        public static void HighlightText(this IDeviceContext dc, Font font, string text,
           Rectangle container, int start, int end, Color highlightForeColor, Color highlightBackColorStart, 
           Color? highlightBackColorEnd, DrawTextFlags? flags = null)
        {
            IntPtr hdc = dc.GetHdc();
            IntPtr _font = SelectObject(hdc, font.ToHfont());

            Dimension dm = container;
            var flag = flags.getMeasureFlag(false);

            SetBkMode(hdc, ColorTranslator.ToWin32(Color.Transparent));

            //first draw whole text
            DrawText(hdc, text, text.Length, ref dm, 0);

            //now get the highlight rectangle which will draw the highlighted text
            Rectangle textBound, uptoIndex;
            var rect = hdc.rangeBound(text, container, start, end, out textBound, out uptoIndex, flags: flags);
            dm = rect;

            var _backColorEnd = highlightBackColorEnd ?? highlightBackColorStart;
            hdc.Fill(rect, highlightBackColorStart, _backColorEnd, Angle.A0);

            SetTextColor(hdc, ColorTranslator.ToWin32(highlightForeColor));

            if (start < 0 || start > text.Length - 1 || end < 0 || end > text.Length - 1)
                throw new Exception("start and end value must be with in text length");

            var _text = text.Substring(start, end - start + 1);
            DrawText(hdc, _text, _text.Length, ref dm, 0);

            DeleteObject(SelectObject(hdc, _font));
            dc.ReleaseHdc();
        }

        public static Rectangle RangeBound(this IDeviceContext dc, Font font, string text,
           Rectangle container, int start, int end, DrawTextFlags? flags = null)
        {
            Rectangle textBound, uptoIndex;
            return dc.RangeBound(font, text, container, start, end, out textBound, out uptoIndex, flags);
        }

        public static Rectangle GetPortionRectangleToHighlight(this ListBox control, int itemIndex, int startIndex, int endIndex)
        {
            var container = control.GetItemRectangle(itemIndex);
            var text = control.GetItemText(itemIndex);
            Rectangle rect;

            using (Graphics g = control.CreateGraphics())
            {
                rect = g.RangeBound(control.Font, text, container, startIndex, endIndex);

            }
            return rect;
        }

        public static bool Fill(this IntPtr hdc, Rectangle rc, Color c1,
           Color c2, Angle angle)
        {
            return hdc.Fill(rc.X, rc.Y, rc.Right, rc.Bottom, c1, c2, angle);
        }

        public static bool Fill(this IntPtr hdc, int x0, int y0, int x1, int y1, Color c1, Color c2, Angle angle)
        {
            Trivertex[] t = new Trivertex[4]
            {
                new Trivertex(x0, y0, c1),
                new Trivertex(x1, y1, c2),
                new Trivertex(x0, y1, c1, c2),
                new Trivertex(x1, y0, c1, c2)
            };
            uint[] pMesh = new uint[] { 0, 1, 2, 0, 1, 3 };

            switch ((int)angle % 180)
            {
                case 0:
                    return GradientFill(hdc, t, 2, pMesh, 1, H);
                case 45:
                    return GradientFill(hdc, t, 4, pMesh, 2, T);
                case 90:
                    return GradientFill(hdc, t, 2, pMesh, 1, V);
                case 135:
                    t[0].x = x1;
                    t[3].x = x0;
                    t[1].x = x0;
                    t[2].x = x1;
                    return GradientFill(hdc, t, 4, pMesh, 2, T);
                default:
                    return false;
            }
        }

        #endregion

        #region get the highlight rectangle
        static Rectangle RangeBound(this IDeviceContext dc, Font font, string text,
            Rectangle container, int start, int end, out Rectangle textBound, out Rectangle uptoIndex, DrawTextFlags? flags = null)
        {
            textBound = Rectangle.Empty;
            uptoIndex = Rectangle.Empty;

            if (string.IsNullOrEmpty(text)) return Rectangle.Empty;

            IntPtr hdc = dc.GetHdc();
            IntPtr _font = SelectObject(hdc, font.ToHfont());

            var rc = hdc.rangeBound(text, container, start, end, out textBound, out uptoIndex, flags: flags);

            DeleteObject(SelectObject(hdc, _font));
            dc.ReleaseHdc();
            return rc;
        }

        static TextMeasurement charRectangle(this IntPtr hdc, string text, Rectangle container,
            string wholeText = null, Point? point = null, bool adjustByPoint = false, DrawTextFlags? flags = null)
        {
            if (string.IsNullOrEmpty(text)) return TextMeasurement.Default;

            TextMeasurement measurement = new TextMeasurement();
            Rectangle textBound;

            wholeText = (wholeText ?? text);

            var location = container.Location;

            var measureWholeText = point == null;
            measurement.UserPoint = point ?? Point.Empty;


            textBound = hdc.textBound(wholeText, container, flags: flags);

            var rect = textBound;
            var p = point ?? new Point(container.Right, container.Y);

            if (!measureWholeText)
            {
                if (p.X > textBound.Right)
                    p.X = textBound.Right;
                else if (p.X < textBound.Left)
                    p.X = textBound.X;
            }

            var charIndex = 0;

            var result = hdc.charRectangle(text, ref p, rect, flags, measureWholeText);

            charIndex = Math.Max(0, result.Item2);
            var rectangles = result.Item1;

            measurement.Bounds = rectangles[0];
            measurement.TextBounds = (measureWholeText) ? rectangles[1] : textBound;
            rectangles[1] = measurement.TextBounds;

            if (!measureWholeText && adjustByPoint && charIndex > 0)
            {
                float middle = (float)measurement.Bounds.Left +
                    measurement.Bounds.Width / 2;
                if (p.X > middle - 1)
                {
                    Rectangle r;
                    Dimension r1 = measurement.TextBounds;

                    var newresult = hdc.charBound(text, charIndex + 2, ref r1,
                        (int)flags.getMeasureFlag(false), out r);

                    if (!newresult.Equals(measurement.Bounds) &&
                        newresult.X > measurement.Bounds.X)
                    {
                        charIndex++;
                        measurement.Bounds = newresult;
                    }
                }
            }
            if (measurement.Bounds.Size.Width<=0)
                measurement.Bounds = new Rectangle(measurement.Bounds.Location, new Size(2, 2));

            measurement.CharIndex = charIndex;
            measurement.Char = '\0';
            measurement.Char = text[Math.Min(charIndex, text.Length - 1)];
            return measurement;
        }

        static Tuple<Rectangle[], int> charRectangle(this IntPtr hdc, string text, ref Point p, Rectangle rect,
             DrawTextFlags? flags, bool measureWholeText = false)
        {
            int i = 0;

            int middle = text.Length / 2, start = 0;
            bool first = true;
            do
            {
                var upto = hdc.Measure(text.Substring(0, middle), null, rect, flags);
                bool found = upto.Has(p);
                if (!found)
                {
                    start = middle;
                    middle += (text.Length - middle) / 2;
                    first = false;
                    if (start == middle) break;
                }
                else break;
            } while (middle > 1 && text.Length - middle > 1);

            if (first)
            {
                return hdc.charRectangle(text.Substring(0, middle),
                    ref p, rect, flags);
            }
            else
            {
                Rectangle[] list = new Rectangle[2];
                for (i = start; i <= middle; i++)
                {
                    if (hdc.Measure(text, out list, p, i + 1, rect, flags))
                        break;
                }
                i = Math.Max(i, 0);
                return new Tuple<Rectangle[], int>(list, i);
            }
        }

        static Rectangle charBound(this IntPtr hdc, string text, int len,
           ref Dimension bounds, int flag, out Rectangle whole)
        {
            DrawText(hdc, text, len, ref bounds, flag);
            whole = bounds;
            var rc = bounds;
            if (len - 1 > 0 && len <= text.Length)
            {
                DrawText(hdc, text.Substring(0, len - 1), len - 1, ref rc, flag);
                rc = Rectangle.FromLTRB(rc.Right, bounds.Top, bounds.Right, bounds.Bottom);
            }
            return rc;
        }

       static Rectangle rangeBound(this IntPtr hdc, string text, Rectangle container, int start, int end,
            out Rectangle textBound, out Rectangle uptoIndex,   DrawTextFlags? flags = null)
        {
            textBound = Rectangle.Empty;
            uptoIndex = Rectangle.Empty;

            if (string.IsNullOrEmpty(text)) return Rectangle.Empty;

            var location = container.Location;
            textBound = hdc.textBound(text, container, flags);

            Dimension rect = textBound;
            var flag = flags.getMeasureFlag(false);

            start++;
            var text1 = text.Substring(0, start);
            var rc = hdc.charBound(text1, text1.Length, ref rect, (int)flag, out uptoIndex);

            end++;
            var text2 = text.Substring(0, end);
            DrawText(hdc, text2, text2.Length, ref rect, (int)flag);

            return Rectangle.FromLTRB(rc.Left, rect.Top, rect.Right, rect.Bottom);
        }

        static Rectangle textBound(this IntPtr hdc, string text, Rectangle container,  DrawTextFlags? flags = null)
        {
            Rectangle rc = Rectangle.Empty;

            if (string.IsNullOrEmpty(text)) return rc;
            Point p = container.Location;

            var r = hdc.Measure(text, text.Length, flags: flags);
            return new Rectangle(p, r.Size);
        }


        static DrawTextFlags getMeasureFlag(this DrawTextFlags? flags, bool textboxControl = false)
        {
            DrawTextFlags flag = DrawTextFlags.CalculateArea;
            if (flags != null) flag |= flags.Value;

            flag |= DrawTextFlags.WordBreak | DrawTextFlags.NoPrefix
                | DrawTextFlags.NoPadding | DrawTextFlags.NoClipping;

            if (textboxControl) flag |= DrawTextFlags.TextBoxControl;
            else flag |= DrawTextFlags.SingleLine;
            return flag;
        }

        static Rectangle RangeBound(this IntPtr hdc, string text,
           Rectangle container, int start, int end, DrawTextFlags? flags = null)
        {
            Rectangle textBound, uptoIndex;
            return hdc.rangeBound(text, container, start, end, out textBound, out uptoIndex, flags);
        }

        static Rectangle Measure(this IntPtr hdc, string text, int? length = null,
           Rectangle? rect = null, DrawTextFlags? flags = null)
        {
            if (string.IsNullOrEmpty(text)) return Rectangle.Empty;
            Dimension bounds = rect ?? dummy;

            var len = length ?? text.Length;
            var flag = flags.getMeasureFlag(false);

            var i = DrawText(hdc, text, len, ref bounds, (int)flag);

            return bounds;
        }

        static bool Measure(this IntPtr hdc, string text, out Rectangle[] rectangles, Point p,
            int? length = null, Rectangle? rect = null,  DrawTextFlags? flags = null)
        {
            rectangles = new Rectangle[2];

            if (string.IsNullOrEmpty(text)) return true;
            Dimension bounds = rect ?? dummy;

            var len = length ?? text.Length;
            var flag = flags.getMeasureFlag(false);

            Rectangle rc, rc1;
            rc1 = hdc.charBound(text, len, ref bounds, (int)flag, out rc);
            rectangles = new Rectangle[] { rc1, rc };
            return (rectangles[0].Left < bounds.Left || rectangles[0].Has(p.X));
        }

        static bool Has(this Rectangle rect, int x = -1,
            int y = -1, int checkRightUpto = -1, int checkBottomUpto = -1)
        {
            if (x == -1 && y == -1)
            {
                x = 0;
                y = 0;
            }
            else
            {
                x = x == -1 ? rect.X : x;
                y = y == -1 ? rect.Y : y;
            }
            if (checkRightUpto == -1)
            {
                checkRightUpto = rect.Width;
            }
            if (checkBottomUpto == -1)
            {
                checkBottomUpto = rect.Height;
            }
            return x >= rect.Left && x <= rect.Left +
                checkRightUpto && y >= rect.Top &&
                y <= rect.Top + checkBottomUpto;
        }

        static bool Has(this Rectangle rect, Point p,
           int checkRightUpto = -1, int checkBottomUpto = -1)
        {
            return rect.Has(p.X, p.Y, checkRightUpto, checkBottomUpto);
        }
        #endregion
    }

    #region structs
    [StructLayout(LayoutKind.Sequential)]
    public struct Dimension
    {
        public int Left, Top, Right, Bottom;

        public Dimension(int left, int top, int right, int bottom)
        {
            this.Left = left;
            this.Right = right;
            this.Top = top;
            this.Bottom = bottom;
        }
        public Dimension(Rectangle r)
        {
            this.Left = r.Left;
            this.Top = r.Top;
            this.Bottom = r.Bottom;
            this.Right = r.Right;
        }
        public static implicit operator Rectangle(Dimension rc)
        {
            return Rectangle.FromLTRB(rc.Left, rc.Top, rc.Right, rc.Bottom);
        }
        public static implicit operator Dimension(Rectangle rc)
        {
            return new Dimension(rc);
        }

        public static Dimension Default
        {
            get { return new Dimension(0, 0, 1, 1); }
        }
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct Trivertex
    {
        public int x;
        public int y;
        public ushort Red;
        public ushort Green;
        public ushort Blue;
        public ushort Alpha;

        public Trivertex(int x, int y, Color color)
            : this(x, y, color.R, color.G, color.B, color.A)
        {
        }
        public Trivertex(int x, int y, Color color, Color other)
            : this(x, y, color.R, color.G, color.B, color.A, other)
        {
        }
        public Trivertex(int x, int y, ushort red, ushort green, ushort blue, ushort alpha)
        {
            this.x = x;
            this.y = y;
            Red = (ushort)(red << 8);
            Green = (ushort)(green << 8);
            Blue = (ushort)(blue << 8);
            Alpha = (ushort)(alpha << 8);
        }
        public Trivertex(int x, int y, ushort red, ushort green, ushort blue, ushort alpha, Color other)
        {
            this.x = x;
            this.y = y;
            Red = (ushort)((red + other.R / 2) << 8);
            Green = (ushort)((green + other.G / 2) << 8);
            Blue = (ushort)((blue + other.B / 2) << 8);
            Alpha = (ushort)((alpha + other.A / 2) << 8);
        }

        public static ushort R(Color c)
        {
            return (ushort)(c.R << 8);
        }
        public static ushort G(Color c)
        {
            return (ushort)(c.G << 8);
        }
        public static ushort B(Color c)
        {
            return (ushort)(c.B << 8);
        }
        public static ushort R(Color c, Color c1)
        {
            return (ushort)(((c.R + c1.R / 2)) << 8);
        }
        public static ushort G(Color c, Color c1)
        {
            return (ushort)(((c.G + c1.G / 2)) << 8);
        }
        public static ushort B(Color c, Color c1)
        {
            return (ushort)(((c.B + c1.B / 2)) << 8);
        }
    }
    #endregion

    #region textmeasurement interface + class
    public interface ITextMeasurement : ICloneable
    {
        int CharIndex { get; set; }
        int PreviousIndex { get; }
        Rectangle Bounds { get; }
        Rectangle TextBounds { get; }
        char Char { get; }
        Point UserPoint { get; }

        void CopyFrom(ITextMeasurement other);
    }
    public class TextMeasurement : ITextMeasurement
    {
        Rectangle now, textBound;

        public virtual Rectangle Bounds
        {
            get
            {
                return now;
            }
            set { now = value; }
        }
        public virtual Rectangle TextBounds
        {
            get
            {
                return textBound; ;
            }
            set { textBound = value; }
        }

        public virtual int CharIndex { get; set; }
        public virtual int PreviousIndex { get; set; }
        public virtual char Char { get; set; }
        public Point UserPoint { get; set; }

        public virtual void CopyFrom(ITextMeasurement tm)
        {
            PreviousIndex = tm.PreviousIndex;
            CharIndex = tm.CharIndex;
            Bounds = tm.Bounds;
            Char = tm.Char;
            TextBounds = tm.TextBounds;
            UserPoint = tm.UserPoint;
            if (UserPoint.IsEmpty) UserPoint = Bounds.Location;
        }
        public virtual object Clone()
        {
            var tm = new TextMeasurement();
            tm.CopyFrom(this);
            return tm;
        }
        protected virtual void ResetBounds(Point p)
        {
            ResetBounds(p.X, p.Y);
        }
        protected virtual void ResetBounds(int? lineX = null, int? lineY = null)
        {
            if (lineX.HasValue)
            {
                now.X = lineX.Value;
                textBound.X = lineX.Value;
            }
            if (lineY.HasValue)
            {
                now.Y = lineY.Value;
                textBound.Y = lineY.Value;
            }
        }
        protected virtual void ResetEmptyBounds(Rectangle rc)
        {
            now = rc;
            textBound = rc;
        }
        public static TextMeasurement Default
        {
            get { return new TextMeasurement(); }
        }
    }
    #endregion

    #region enums
    public enum DrawTextFlags
    {
        CalculateArea = 0x00000400,
        WordBreak = 0x00000010,
        TextBoxControl = 0x00002000,
        Top = 0x00000000,
        Left = 0x00000000,
        HorizontalCenter = 0x00000001,
        Right = 0x00000002,
        VerticalCenter = 0x00000004,
        Bottom = 0x00000008,
        SingleLine = 0x00000020,
        ExpandTabs = 0x00000040,
        TabStop = 0x00000080,
        NoClipping = 0x00000100,
        ExternalLeading = 0x00000200,
        NoPrefix = 0x00000800,
        Internal = 0x00001000,
        PathEllipsis = 0x00004000,
        EndEllipsis = 0x00008000,
        WordEllipsis = 0x00040000,
        ModifyString = 0x00010000,
        RightToLeft = 0x00020000,
        NoFullWidthCharacterBreak = 0x00080000,
        HidePrefix = 0x00100000,
        PrefixOnly = 0x00200000,
        NoPadding = 0x10000000,
    }
    public enum Angle
    {
        A0 = 0,
        A45 = 45,
        A90 = 90,
        A135 = 135,
        A180 = 180
    }
    #endregion
}

假设索引2处的ItemText是“StackOverFlow是一个很棒的网站”，你想突出显示“StackOverFlow”，然后你的startIndex = 0和endIndex = 12。

要突出显示部分文字，请使用HighlightItemText方法：

listBox.HilightItemText(2, 0, 12, Color.Black, Color.Gold, Color.Yellow);

要获得突出显示的坐标，请使用GetPortionRectangleToHighlight方法获取要突出显示的文本部分的坐标。请注意，您只需要传递开始和结束索引以及部分文本。

所以调用函数如：

var portionRectangle = listBox1.GetPortionRectangleToHighlight (2, 0, 12);

查看附图作为概念的工作证明。

Answer 2

一个简单的例子是这样的：

    private string[] _sentences = {
        "Old height on pictureOne: 766",
        "New height on pictureOne: 900",
        "",
        "Forcing width on objectX"
    };

    private void Form1Paint(object sender, PaintEventArgs e) {
        int y = 10; //Start position
        int x;

        foreach (string s in _sentences) {
            x = 0; //Start position
            foreach (string word in s.Split(' ')) {
                if (ShouldHeighlightWord(word)) {
                    e.Graphics.DrawString(word + " ", this.Font, new SolidBrush(Color.Red), x, y);
                }
                else {
                    e.Graphics.DrawString(word + " ", this.Font, new SolidBrush(Color.Black), x, y);
                }
                x += (int)e.Graphics.MeasureString(word + " ", this.Font).Width;
            }

            y += (int)Math.Ceiling(e.Graphics.MeasureString("I", this.Font).Height);
        }
    }

    private bool ShouldHeighlightWord(string word) {
        switch (word) {
            case "on":
            case "Old":
                return true;
            default:
                return false;
        }
    }

此代码只是将字符串绘制到空表单上，而不是突出显示它只是将颜色更改为红色。

但我想你明白我的意思。由于我没有更多的代码，很难为你做出更好的例子。

检查时：

if (SomethingToHighlight(item)) {

这只会返回true / false我猜你需要一些东西来返回所有要突出显示的单词，但由于一个单词可以在一个句子中出现两次（或更多），你需要能够在字符串中获得一个位置好。或者一次只取一个字，检查是否应突出显示，然后将其绘制到控件中。

Graphics.MeasureString（） - 查找相对X，Y坐标

2 个答案: