我重载了RichTextBox的OnPaint方法,怎么运行时不被调用?

Question

我重载了RichTextBox的OnPaint方法,怎么运行时不被调用?
重载代码:
protected override void OnPaint(PaintEventArgs e) 
        {
            base.OnPaint(e);            Graphics grp = e.Graphics;             Rectangle rect = new Rectangle(0, 0, this.ClientRectangle.Width, this.ClientRectangle.Height);
            Brush brush = new SolidBrush(Color.Black);            Pen myPen = new Pen(brush);            myPen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dash;
            myPen.Width = 2;
            grp.DrawRectangle(myPen, rect);
        }
代码是在我自己定义的类里面,把这个空间放在Form,运行,在这个函数中打断点,走不到这里.是怎么回事呢?

Answer 1

要这样：using System;
using System.Windows.Forms;namespace MyControls
{
    class RichTextBox : System.Windows.Forms.RichTextBox
    {
         protected override void OnPaint(PaintEventArgs e) 
        { 
            base.OnPaint(e);             Graphics grp = e.Graphics;             Rectangle rect = new Rectangle(0, 0, this.ClientRectangle.Width, this.ClientRectangle.Height); 
            Brush brush = new SolidBrush(Color.Black);             Pen myPen = new Pen(brush);             myPen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dash; 
            myPen.Width = 2; 
            grp.DrawRectangle(myPen, rect); 
        } 
    }
}使用时：using System;
using System.Windows.Forms;
using MyControlsclass Test
{
    RichTextBox richTextBox1;
}

Answer 2

我代码是这样一来的:
using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;namespace AXS.Board.Core.Control
{
    public class RichTextBox : System.Windows.Forms.RichTextBox
    {
       [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
        static extern IntPtr LoadLibrary(string lpFileName);        [DllImport("user32.dll", EntryPoint = "SendMessageA")]
        private static extern int SendMessage(IntPtr hwnd, int wMsg, IntPtr wParam, string lParam);        public EventHandler BdTextChanged = null;
        public RichTextBox()
        {
            this.TextChanged += new EventHandler(RichEdit50_TextChanged);
        }        private void RichEdit50_TextChanged(object sender, EventArgs e)
        {
            int EM_GETLINECOUNT = 0x00BA;//获取总行数的消息号 
            int lc = SendMessage(this.Handle, EM_GETLINECOUNT, IntPtr.Zero, "");
            int sf = this.Font.Height * (lc + 1) + this.Location.Y + 5;            System.Drawing.Graphics grp = default(System.Drawing.Graphics);
            System.Drawing.SizeF TextSize = new System.Drawing.SizeF();            grp = this.CreateGraphics();
            TextSize = grp.MeasureString(this.Text, this.Font);            if (lc * this.Font.Height > this.Height - 10)
            {
                this.Size = new System.Drawing.Size(this.Width, this.Height + this.Font.Height);
            }            if (BdTextChanged != null)
            {
                BdTextChanged(sender, e);
            }
        }        protected override void OnPaint(PaintEventArgs e) 
        {
            base.OnPaint(e);            Graphics grp = e.Graphics;             Rectangle rect = new Rectangle(0, 0, this.ClientRectangle.Width, this.ClientRectangle.Height);
            Brush brush = new SolidBrush(Color.Black);            Pen myPen = new Pen(brush);            myPen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dash;
            myPen.Width = 2;
            grp.DrawRectangle(myPen, rect);
        }
        //protected override CreateParams CreateParams
        //{
        //    get
        //    {
        //        CreateParams prams = base.CreateParams;
        //        if (LoadLibrary("msftedit.dll") != IntPtr.Zero)
        //        {
        //            prams.ExStyle |= 0x020; // transparent 
        //            prams.ClassName = "RICHEDIT50W";
        //        }
        //        return prams;
        //    }
        //}
    }
}
用时仍OnPaint起不到作用.