c#.net上传文件到数据库中(把文件转换成二进制流存在后台数据库)

OpenFileDialog testreportfile = new OpenFileDialog();
testreportfile.InitialDirectory = @"c:/";
testreportfile.RestoreDirectory = true;
testreportfile.Multiselect = false;
if (testreportfile.ShowDialog() == DialogResult.OK)
{
this.textBox8.Text = testreportfile.FileName;
filename = testreportfile.FileName.Substring(testreportfile.FileName.LastIndexOf("//") + 1, (testreportfile.FileName.LastIndexOf(".") - testreportfile.FileName.LastIndexOf("//") - 1)); //文件的名称
filetype = testreportfile.FileName.Substring(testreportfile.FileName.LastIndexOf(".") + 1, (testreportfile.FileName.Length - testreportfile.FileName.LastIndexOf(".") - 1));//文件的扩展名

Stream myStream = testreportfile.OpenFile();
int length = (int)myStream.Length;
filedata = new byte[length];
myStream.Read(filedata, 0, length); myStream.Close();

SqlCommand scwj = new SqlCommand("insert_testreport", myConnection);
scwj.CommandType = CommandType.StoredProcedure;
scwj.Parameters.Add("@PID", SqlDbType.Int);
scwj.Parameters.Add("@TRCode", SqlDbType.VarChar, 20);
scwj.Parameters.Add("@TRDate", SqlDbType.DateTime);
scwj.Parameters.Add("@MMID", SqlDbType.Int);
scwj.Parameters.Add("@TOrgan", SqlDbType.VarChar, 200);
scwj.Parameters.Add("@UName", SqlDbType.VarChar, 20);
scwj.Parameters.Add("@Explian", SqlDbType.VarChar, 200);
scwj.Parameters.Add("@FileName", SqlDbType.VarChar, 40);
scwj.Parameters.Add("@FileType", SqlDbType.Char, 10);
scwj.Parameters.Add("@FileData", SqlDbType.Image);

scwj.Parameters[0].Value = report_add_pid;
scwj.Parameters[1].Value = textBox3.Text.Trim();
scwj.Parameters[2].Value = dateTimePicker1.Value;
scwj.Parameters[3].Value = report_add_mmid;
scwj.Parameters[4].Value = textBox5.Text.Trim();
scwj.Parameters[5].Value = login.strUser;
scwj.Parameters[6].Value = textBox6.Text.Trim();
scwj.Parameters[7].Value = filename;
scwj.Parameters[8].Value = filetype;
scwj.Parameters["@FileData"].Value = filedata;

myConnection.Open();
scwj.ExecuteNonQuery();
myConnection.Close();
}