Bitmap bitmap = new Bitmap(stream) 无效参数？？

[gcxyzxyz]

代码如下：
protected void Button1_Click(object sender, EventArgs e)
{
MemoryStream stream = new MemoryStream();
SqlConnection connection = new SqlConnection("Data Source=.;Initial Catalog=gdseal;Persist Security Info=True;User ID=sa;Password=rsrj");
try
{
string imageid = TextBox1.Text.Trim();
connection.Open();
SqlCommand command = new SqlCommand("select sdimage from SealData where code='" + imageid+ "'", connection);
byte[] image = (byte[])command.ExecuteScalar();
stream.Write(image, 0, image.Length);
Bitmap bitmap = new Bitmap(stream);
Response.ContentType = "image/gif";
bitmap.Save(Response.OutputStream, ImageFormat.Gif);
}
finally
{
connection.Close();
stream.Close();
}
}

只是显示数据库中的字段，老出现无效参数？
那位大侠给个代码也行。

[BearRui]

参考:
//把图片读到pictureBox，再写入数据库

SqlConnection conn=new SqlConnection(@"data source=chenyuming2004\VSdotNET;uid=sa;pwd=cym;database=lhf");
conn.Open();
SqlCommand cmd=new SqlCommand("insert into fuser values ('1a','1b',@i)",conn);
byte[] ib=new Byte[60000];
FileStream fs=new FileStream(@"D:\windows temp\temp\1.jpg",FileMode.Open ,FileAccess.Read );
fs.Read(ib,0,60000);
cmd.Parameters.Add("@i",SqlDbType.Image,(int)fs.Length);
cmd.Parameters["@i"].Value=ib;
cmd.ExecuteNonQuery();
conn.Close();

-------------------------------------------------------
//从数据库读图片到picturebox

SqlConnection conn=new SqlConnection(@"data source=chenyuming2004\VSdotNET;uid=sa;pwd=cym;database=lhf");
conn.Open();
SqlCommand cmd=new SqlCommand("select 照片 from fuser where password='1b'",conn);
SqlDataReader reader=cmd.ExecuteReader();
reader.Read();
MemoryStream buf=new MemoryStream((byte[])reader[0]);
Image image=Image.FromStream(buf,true);
pictureBox1.Image=image;

[gcxyzxyz]

有asp.net 的不

[gcxyzxyz]

只是显示数据库中的字段，老出现无效参数？
那位大侠给个代码也行。