*******richTextBox读取数据库中的image字段的问题?简单，在线等********

Question

richTextBox如何读取数据库中的image字段的问题?保存我已经写好了，winform中，有些不是很熟悉,谢谢;
我这样写总是不行,
 byte[] bWrite = model.PlanExplain; //返回的byte[]
            System.IO.MemoryStream mstream = new System.IO.MemoryStream(bWrite, false);
            richTextBox.LoadFile(mstream, RichTextBoxStreamType.RichText);

Answer 1

try
 
richTextBox.LoadFile(ms, RichTextBoxStreamType.PlainText);orrichTextBox.LoadFile(ms, RichTextBoxStreamType.UnicodePlainText);

Answer 2

richTextBox.LoadFile(mstream, RichTextBoxStreamType.RichText);使用这个重载时出现什么问题呢?
就这么几个重载方法哦 是不是本身读取得数据有问题?

Answer 3

//读取代码,sql数据库是image类型  
richTextBox1.SaveFile("temp.rtf");
 stream = new FileStream("temp.rtf", FileMode.Open, FileAccess.Read);
 int size = Convert.ToInt32(stream.Length);
 Byte[] rtf = new Byte[size];
 stream.Read(rtf, 0, size);

Answer 4

(byte[])ds.Tables[0].Rows[0]["PlanExplain"];

Answer 5

===========这样写 就可以了===========================
==========读取图片========SqlConnection conn = new SqlConnection("Server=.;Database=Northwind;Integrated Security=SSPI");
            string strSql = "select a from c";
            SqlCommand cmd = new SqlCommand(strSql, conn);
            conn.Open();
            SqlDataReader reader = cmd.ExecuteReader();
            reader.Read();
            byte[] bytes = (byte[])reader["a"];
            MemoryStream ms = new MemoryStream(bytes);
            Image image = Image.FromStream(ms);            pictureBox1.Image = image;            reader.Close();
            conn.Close();
===============================写入图片============= OpenFileDialog openfileDialog = new OpenFileDialog();
            openfileDialog.Filter = "Picture Files(*.jpg)|*.jpg|Bmp(*.bmp)|*.bmp|All Files(*.*)|*.*";
            FileStream fileStream;
            openfileDialog.ShowDialog();
            string filepath = openfileDialog.FileName;            //获得图象并把图象转换为byte[]
            fileStream = new FileStream(filepath, FileMode.Open, FileAccess.Read);
            byte[] photoArray = new byte[(int)fileStream.Length];
            fileStream.Read(photoArray, 0, photoArray.Length);
            fileStream.Close();
            try
            {
                pictureBox1.SizeMode = PictureBoxSizeMode.Normal;
                pictureBox1.Image = System.Drawing.Image.FromFile(filepath);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            SqlConnection conn = new SqlConnection("Server=.;Database=Northwind;Integrated Security=SSPI");            //插入语句
            SqlCommand cmd = new SqlCommand("INSERT INTO c(a)VALUES (@a)", conn);            cmd.Parameters.Add("@a",SqlDbType.Image);
            cmd.Parameters["@a"].Value=photoArray;
            conn.Open();
            cmd.ExecuteNonQuery();
            conn.Close();
=========================================

Answer 6

谢谢楼上的，是要用richTextBox的，相信一定能行的。因为这样写就可以
reader = cmd.ExecuteReader();
                reader.Read();
                if (reader.HasRows)
                {
                    if (!reader.IsDBNull(0))
                    {
                        Byte[] rtf = new Byte[Convert.ToInt32((reader.GetBytes(0, 0, null, 0, Int32.MaxValue)))];
                        long bytesReceived = reader.GetBytes(0, 0, rtf, 0, rtf.Length);                        ASCIIEncoding encoding = new ASCIIEncoding();
                        richTextBox1.Rtf = encoding.GetString(rtf, 0, Convert.ToInt32(bytesReceived));
                    }
                }
只不过我用的是dataset,不是dataread,不知道怎么改一下？

Answer 7

只不过我用的是dataset,不是dataread,不知道怎么改一下？
======================== 有区别 吗 ? 如果别人面试的时候 问他们之间的区别 你又是怎么去 回答 :
===
SqlConnection conn = new SqlConnection("Server=.;Database=Northwind;Integrated Security=SSPI");
            string strSql = "select a from c";
            SqlCommand cmd = new SqlCommand(strSql, conn);
            conn.Open();
            SqlDataReader reader = cmd.ExecuteReader();
            reader.Read();
            byte[] bytes = (byte[])reader["a"];
            MemoryStream ms = new MemoryStream(bytes);
            Image image = Image.FromStream(ms);            pictureBox1.Image = image;            reader.Close();
            conn.Close();
===========
SqlConnection conn = new SqlConnection("Server=.;Database=Northwind;Integrated Security=SSPI");
            string strSql = "select a from c"; //SQL 语句自己改动,
            SqlDataAdapter da=New SqlDataAdapter(strSql, conn);            DataSet ds=New DataSet();
            da.Fill(ds);
            
            byte[] bytes = (byte[])ds.Tables[0].rows[0]["列名"];
         MemoryStream ms = new MemoryStream(bytes);
            Image image = Image.FromStream(ms);            pictureBox1.Image = image;            reader.Close();
            conn.Close();

Answer 8

我不是哪个意思
看关键代码：
Byte[] rtf = new Byte[Convert.ToInt32((reader.GetBytes(0, 0, null, 0, Int32.MaxValue)))];
                        long bytesReceived = reader.GetBytes(0, 0, rtf, 0, rtf.Length);                        ASCIIEncoding encoding = new ASCIIEncoding();
                        richTextBox1.Rtf = encoding.GetString(rtf, 0, Convert.ToInt32(bytesReceived));如果是dataset，怎么改一下,不能用pictureBox显示