SQL Read and write pictures when Image.fromstream method tips parameter Error problem resolution

We usually write this.

using (SqlDataReader DRM = Sqlcomm.executereader ())                     {                         DRM. Read ();//The following shows the image stream in the database as it appears in the picture frame.                         MemoryStream ms = new MemoryStream ((byte[]) drm["Logo"]);                         Image img = image.fromstream (ms);                         This.pictureBox1.Image = img;                     }

My writing data

        private void Btnok_click (object sender, EventArgs e) {string name = ""; if (tbxUserName.Text.Trim () = = "") {MessageBox.Show ("name cannot be empty, please re-enter!")                "," prompt ");            Return            } else {name = TbxUserName.Text.Trim ();            } String group = "";            if (cbxGroup.Text.Trim () = = "") {group = "not grouped";            } else {group = CbxGroup.Text.Trim ();            } String phone = TbxTel.Text.Trim ();            String workunit = TbxWorkUnit.Text.Trim ();            string email = TbxEmail.Text.Trim ();            String QQ = TbxQQ.Text.Trim ();            Byte[] B = null; if (Txtfilepath! = "") {try {FileStream fs = new FileStream ( Txtfilepath, FileMode.Open, FileAccess.Read);//type for Open Data permission for read-only not write data int length = Convert.ToInt32 (fs.                    Length);                    b = new Byte[length]; Fs. Read (b, 0, length);//data reads into the B array from number NO. 0 to length-bit fs.                    Close ();//Turn off input/output stream} catch (Exception ex) {b = null; MessageBox.Show (ex.                Message);            }} else {b = pixdata;                } try {using (SqlConnection connection = new SqlConnection (connectionString))                    {//Get the current data in the table ID SqlCommand commandinsert = new SqlCommand ();                    Commandinsert.connection = Connection; Connection.                    Close (); Connection.                    Open (); Insert Data Commandinsert.commandtext = "Use DB_TXL UPDATE tb_busicinfo set groups= @Groups, [Email pro Tected],[email protected],[email protected],[email pRotected],[email protected],[email protected] ";                    Commandinsert.commandtext + = "where [email protected]";                    COMMANDINSERT.PARAMETERS.ADD ("@ID", SqlDbType.Int);                    COMMANDINSERT.PARAMETERS.ADD ("@Groups", SqlDbType.VarChar, 50);                    COMMANDINSERT.PARAMETERS.ADD ("@Name", SqlDbType.VarChar, 20);                    COMMANDINSERT.PARAMETERS.ADD ("@WorkUnit", SqlDbType.VarChar, 50);                    COMMANDINSERT.PARAMETERS.ADD ("@Phone", SqlDbType.VarChar, 14);                    COMMANDINSERT.PARAMETERS.ADD ("@Email", SqlDbType.VarChar, 50);                    COMMANDINSERT.PARAMETERS.ADD ("@QQ", SqlDbType.VarChar, 20);                    COMMANDINSERT.PARAMETERS.ADD ("@Picture", sqldbtype.image),//image type can not be written wrong!! commandinsert.parameters["@ID"].                  Value = ID; commandinsert.parameters["@UserName"].                    Value = strUserName; commandinsert.parameters["@Groups"]. Value = Group; commandinsert.parameters["@Name"].                    Value = name; commandinsert.parameters["@WorkUnit"].                    Value = Workunit; commandinsert.parameters["@Phone"].                    Value = phone; commandinsert.parameters["@Email"].                    Value = email; commandinsert.parameters["@QQ"].                    Value = QQ; Commandinsert.parameters[""].                    value=; if (Txtfilepath = = "" && pixdata==null) {commandinsert.parameters["@Pic Ture "].                        Value = Dbnull.value;//dbnull does not exist, null} else { commandinsert.parameters["@Picture"].                    Value = b;                    } commandinsert.executenonquery (); Connection.                    Close ();                DialogResult = DialogResult.OK; }} catch (Exception ex) {MessageBox.Show (ex). Message);     }   } 

My reading data

     private void Frmedit_load (object sender, EventArgs e) {try {using (SqlC onnection connection = new SqlConnection (connectionString)) {string commandstring = "se Lect * from Tb_busicinfo where id= "+ ID.                    ToString () + "";                    SqlCommand command = new SqlCommand (commandstring, connection); Connection.                    Open (); SqlDataReader reader = command.                    ExecuteReader (); if (reader.                        Read ()) {Tbxusername.text = convert.tostring (reader["Name"]);                        Cbxgroup.text = convert.tostring (reader["Groups"]);                        Tbxtel.text = convert.tostring (reader["Phone"]);                        Tbxworkunit.text = convert.tostring (reader["Workunit"]);                        Tbxemail.text = convert.tostring (reader["Email"]);     Tbxqq.text = convert.tostring (reader["QQ"]);                   if (reader["picture"] = = DBNull.Value) {pbxpicture.i                        Mage = TongXunLu.Properties.Resources.defaultPix; } else {//string a=reader["picture"].                         ToString ();                           Byte[] B = (byte[]) ((reader["Picture"]));                            MemoryStream buf = new MemoryStream ((byte[]) reader["picture"]);                            Image image = Image.fromstream (BUF);                            Bitmap BT = new Bitmap (image);                            Pbxpicture.image = BT;                          Pbxpicture.image = Image; Pbxpicture.image = Image.fromstream (new MemoryStream (b));//read out the binary stream?? Problem} reader.                    Close (); Connection.                Close (); }} catch (Exception ex) {                MessageBox.Show (ex.            Message); }        }

While reading the data, some errors may occur while writing the data.

Sure enough, I was searching for an array of byte[] when I found that there were more than 20,000 reads when there were only 50.

So I thought maybe there was something wrong at the time of writing, so

COMMANDINSERT.PARAMETERS.ADD ("@Picture", sqldbtype.image,50);

Change to CommandInsert.Parameters.Add ("@Picture", sqldbtype.image);

The photos are displayed properly.

Reference to the http://blog.csdn.net/zystory/article/details/4399338

There's something wrong with your data, and it doesn't matter what you read.
New SqlParameter ("@L_RolePic", Sqldbtype.image, 16) changed to New SqlParameter ("@L_RolePic", Sqldbtype.image),