将RichTextBox的内容直接写入数据库：

 将RichTextBox的内容直接写入数据库：
 private void button1_Click(object sender, EventArgs e)
 {
    System.IO.MemoryStream mstream = new System.IO.MemoryStream();
    this.richTextBox1.SaveFile(mstream, RichTextBoxStreamType.RichText);
    //将流转换成数组
    byte[] bWrite = mstream.ToArray();
    //将数组写入数据库
    System.Data.SqlClient.SqlParameter[] pram ={
           sqlHelper.MakeInParam("@XX",System.Data.SqlDbType.Image)
    };
    pram[].Value = bWrite;
    sqlHelper.RunSql("insert into XXX (XX) values (@XX)", pram);
 }
 将数据库中的RTF读出并填充到RichTextBox
 private void button2_Click(object sender, EventArgs e)
 {
    //从数据库中读出数据
    DataTable dt=sqlHelper.GetDataTable("select XX from XXX where .....");
    byte[] bWrite = (byte[])dt.Rows[][];
    //将数组转换成stream
    System.IO.MemoryStream mstream = new System.IO.MemoryStream(bWrite, false);
    //将stream填充到RichTextBox
    this.richTextBox1.LoadFile(mstream, RichTextBoxStreamType.RichText);
 }