C#中怎么实现文本框背景透明

C#中如何实现文本框背景透明？
这次准备写一个日志小程序。想实现如qq上面的背景为漂亮图片的信纸功能。但发现textBox似乎不支持背景透明，请教如何重写这个类来实现文本框的背景透明或者有其他办法可以解决这个问题，谢谢！

[解决办法]

C# code

public class RichEdit50 : RichTextBox    {        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]        static extern IntPtr LoadLibrary(string lpFileName);        protected override CreateParams CreateParams        {            get            {                CreateParams prams = base.CreateParams;                if (LoadLibrary("msftedit.dll") != IntPtr.Zero)                {                    prams.ExStyle |= 0x020; // transparent                     prams.ClassName = "RICHEDIT50W";                }                return prams;            }        }    }
[解决办法]
C# code
using System;using System.Collections.Generic;using System.Text;using System.Runtime.InteropServices;using System.Windows.Forms;namespace Controls{    public class RichEdit50 : RichTextBox    {        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]        static extern IntPtr LoadLibrary(string lpFileName);        protected override CreateParams CreateParams        {            get            {                CreateParams prams = base.CreateParams;                if (LoadLibrary("msftedit.dll") != IntPtr.Zero)                {                    prams.ExStyle |= 0x020; // transparent                     prams.ClassName = "RICHEDIT50W";                }                return prams;            }        }    }}