When I insert an image into a SQL Server database, if the image is null, then it inserts a 0x value into the database image column.
When I retrieve the image with 0x hex value, I get an error:
Parameter is not valid
string strsql = "SELECT [ID],PIC_Name FROM [HRMS].[dbo].[Employee_PC] where Id = '" + mFieldValue1 + "'";
myconn = new OleDbConnection(clsConnections.conString);
myconn.Open();
cmd = new OleDbCommand(strsql, myconn);
OleDbDataReader dr = null;
dr = cmd.ExecuteReader();
while (dr.Read())
{
if ((byte[])dr[1] == null )
//if (picData == null)
{
pictureBox1.Image = null;
}
else
{
MemoryStream ms = new MemoryStream((byte[])dr[1]);
ms.Position = 0;
pictureBox1.Image = new Bitmap(ms);
}
}
dr[1] won't be null, so neither will (byte[])dr[1]. You want to check the first byte in that array.
byte[] picData = (byte[])dr[1];
if (picData[0] == 0)
{
pictureBox1.Image = null;
}
else
{
MemoryStream ms = new MemoryStream(picData);
ms.Position = 0;
pictureBox1.Image = new Bitmap(ms);
}
private void view_Load(object sender, EventArgs e)
{
try
{
SqlConnection con = new SqlConnection();
con.ConnectionString = "Data Source=SOFT;Initial Catalog=Dev01;Integrated Security=True";
con.Open();
//Retrieve BLOB from database into DataSet.
SqlDataReader myReader = null;
SqlCommand cmd = new SqlCommand("select * from empdetails", con);
myReader = cmd.ExecuteReader();
while (myReader.Read())
{
lbl_fname.Text = myReader["firstname"].ToString();
lbl_mname.Text = myReader["middlename"].ToString();
lbl_lname.Text = myReader["lastname"].ToString();
lbl_gender.Text = myReader["gender"].ToString();
lbl_dob.Text = myReader["dob"].ToString();
lbl_qualification.Text = myReader["qualification"].ToString();
lbl_skills.Text = myReader["skills"].ToString();
lbl_userid.Text = myReader["username"].ToString();
lbl_pwd.Text = myReader["password"].ToString();
lbl_cpwd.Text = myReader["confirmpassword"].ToString();
lbl_mno.Text = myReader["mobilenumber"].ToString();
lbl_altmno.Text = myReader["alternativenumber"].ToString();
lbl_email.Text = myReader["email"].ToString();
lbl_presentadd.Text = myReader["presentaddress"].ToString();
lbl_permanentadd.Text = myReader["permanentaddress"].ToString();
}
myReader.Close();
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds, "empdetails");
int c = ds.Tables["empdetails"].Rows.Count;
if (c > 0)
{
//BLOB is read into Byte array, then used to construct MemoryStream,
//then passed to PictureBox.
//SqlCommand cmd1=new SqlCommand("Select photo from empdetails");
Byte[] bytedata = new Byte[0];
bytedata = (Byte[])(ds.Tables["empdetails"].Rows[c - 1]["photo"]);
MemoryStream ms = new MemoryStream(bytedata);
pictureBox1.Image = Image.FromStream(ms,true); //HERE I AM GETTING ERROR
}
con.Close();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
I already checked various pages but that didn't solve my problem. I am getting an error only in this part:
"pictureBox1.Image = Image.FromStream(ms,true);"
The data type of your column should be image try
public byte[] ConvertImageToByte(Image image, ImageFormat format)
{
var stream = new MemoryStream();
image.Save(stream, format);
return stream.ToArray();
}
public Image ConvertBytesToImage(object _image)
{
byte[] byteImage = (byte[])(_image);
MemoryStream ms = new MemoryStream(byteImage);
ms.Write(byteImage, 0, byteImage.Length);
Image img = Image.FromStream(ms);
return img;
}
Saving the byte in your database
OpenFileDialog file = new OpenFileDialog();
file.Title = "Please Select the Employee Photo (Dimension 128x128)";
file.Filter = "JPEG Files|*.jpg|Bitmap Files|*.bmp|Gif Files|*.gif|PNG Files|*.png";
file.DefaultExt = "jpg";
file.ShowDialog();
if (!string.IsNullOrEmpty(file.FileName))
{
byte[] bytePhoto = ConvertImageToBytes(Image.FromFile(file.FileName), ImageFormat.Png);
//bytePhoto is the object to save in your database
}
Retrieve the byte and display as image
byte[] bytePhoto = (byte[])ds.Tables["empdetails"].Rows[0]["Photo"];
pictureBox1.Image = ConvertBytesToImage(bytePhoto);
In a C# silverlight application I've got a datagrid control that gets contact details from an sql database table. I can add new details to the datagrid by typing in the textboxes and clicking the add button. there is an upload button to upload an image in the Image control and works fine. but I can't seem to save an image for each contact in the table and veiw it along with the other information using wcf service.
here is what I've wrote in my upload image button:
private void uploadbtn_Click_1(object sender, RoutedEventArgs e)
{
OpenFileDialog openFileDialog = new OpenFileDialog();
openFileDialog.Filter = "JPEG files|*.jpg";
//openFileDialog.Filter = "Images (*.jpg, *.png, *.bmp)|*.jpg;*.png;*.bmp";
if (openFileDialog.ShowDialog() == true)
{
Stream stream = (Stream)openFileDialog.File.OpenRead();
byte[] bytes = new byte[stream.Length];
stream.Read(bytes, 0, (int)stream.Length);
BitmapImage bi = new BitmapImage();
bi.SetSource(stream);
MyImage.Source = bi;
string fileName = openFileDialog.File.Name;
}
}
in my add contact button I have :
ServiceReference1.Contact contact = new ServiceReference1.Contact();
ServiceReference1.Service1Client connection = new ServiceReference1.Service1Client();
connection.InsertContactCompleted += new EventHandler<ServiceReference1.InsertContactCompletedEventArgs>(connection_InsertContactCompleted);
contact.ConName = txtname.Text;
contact.ConNumber = txtnumber.Text;
contact.ConDescription = txtdescription.Text;
and in the service :
[OperationContract]
public int InsertContact(Contact cnt)
{
using (SqlConnection con = new SqlConnection(connection))
{
using (SqlCommand cmd = new SqlCommand())
{
cmd.Connection = con;
cmd.CommandText = " insert into Contact(ConName, ConNumber,ConDescription) values(#1,#2,#3)";
cmd.CommandTimeout = 300;
cmd.Parameters.Add("#1", System.Data.SqlDbType.VarChar, 50).Value = cnt.ConName;
cmd.Parameters.Add("#2", System.Data.SqlDbType.VarChar, 50).Value = cnt.ConNumber;
cmd.Parameters.Add("#3", System.Data.SqlDbType.VarChar, 50).Value = cnt.ConDescription;
con.Open();
int i = cmd.ExecuteNonQuery();
con.Close();
if (i > 0)
{
return i;
}
else
{
return 0;
}
}
}
}
I don't know how to add the image to these codes.
private void btnread_Click(object sender, EventArgs e)
{
MySqlConnection connection = new MySqlConnection(MyConnectionString);
connection.Open();
MySqlCommand cmd = connection.CreateCommand();
cmd.CommandText = "SELECT imagecol FROM imgtable WHERE id = 17";
MySqlDataAdapter adap = new MySqlDataAdapter(cmd);`enter code here`
DataTable dt = new DataTable();
adap.Fill(dt);
string b = dt.Rows[0]["imagecol"].ToString();
byte[] storedImage = System.Text.Encoding.ASCII.GetBytes(b);
byte[] ss = (byte[])dt.Rows[0]["imagecol"];
Image newImage;
using (MemoryStream stream = new MemoryStream(storedImage))
{
newImage = Image.FromStream(stream);
}
//// Display to make sure code works
picbox.Image = newImage;
connection.Close();
}
You don't need to convert to byte[] to string then back to byte[] using ASCII.GetBytes.
This should solve your problem.
using (MemoryStream stream = new MemoryStream(ss))
{
newImage = Image.FromStream(stream);
}
Side note: Give proper names for members even when you write a sample application. ss is not meaningful.
Following are the links which describe connection to MySQL:
http://www.codeproject.com/KB/aspnet/asp_net_and_mysql.aspx
http://www.codeproject.com/KB/aspnet/image_asp.aspx
Here is the code to display image from mysql database:
protected void Page_Load(object sender, EventArgs e)
{
MySqlConnection conn = new MySqlConnection(db);
conn.Open();
string s;
s = Session["t"].ToString();
string commantext = "select img_id,img_file,img_type,img_name from image where img_name='"+s+"'";
// string commantext = "select img_id,img_file,img_type,img_name from image";
// DataSet ds = MySqlHelper.ExecuteDataset(conn, commantext);
MySqlCommand cmd = new MySqlCommand(commantext,conn);
cmd.Parameters.Add("?img_id", MySqlDbType.Int32).Value = s;
// DataTable dt = ds.Tables[0];
DataTable dt = GetData(cmd);
while(dt !=null)
{
Byte[] bytes = (Byte[])dt.Rows[0]["img_file"];
// Byte[] bytes = (Byte[])dt.Rows[1][] ;
Response.Buffer = true;
Response.Charset = "";
Response.Cache.SetCacheability(HttpCacheability.NoCache);
Response.ContentType = dt.Rows[0]["img_type"].ToString();
Response.AddHeader("content-disposition", "attachment;filename="
+ dt.Rows[0]["img_name"].ToString());
Response.BinaryWrite(bytes);
Response.Flush();
Response.End();
}
conn.Close();
}
private DataTable GetData(MySqlCommand cmd)
{
DataTable dt = new DataTable();
//String strConnString = System.Configuration.ConfigurationManager.ConnectionStrings["conString"].ConnectionString;
MySqlConnection con = new MySqlConnection(db);
MySqlDataAdapter sda = new MySqlDataAdapter();
cmd.CommandType = CommandType.Text;
cmd.Connection = con;
try
{
con.Open();
sda.SelectCommand = cmd;
sda.Fill(dt);
return dt;
}
catch
{ return null;
}
finally
{ con.Close();
sda.Dispose();
con.Dispose();
}
}
My code to upload image file to mysql database is as below.
protected void Button1_Click(object sender, EventArgs e)
{
Stream img_strm = File1.PostedFile.InputStream;
int img_len = File1.PostedFile.ContentLength;
string strtype = File1.PostedFile.ContentType;
//code snippet to determine image height and width.
System.Drawing.Image i = System.Drawing.Image.FromStream(img_strm);
int fileheight = int.Parse(i.Width.ToString());
int filewidth = int.Parse(i.Height.ToString());
strname = Text1.Value;
//Session["t"] = strname;
byte[] imgData = new byte[img_len];
int n = img_strm.Read(imgData, 0, img_len);
int result = saveToDb(strname, imgData, strtype);
}
private int saveToDb(string imgName, byte[] imgbin, string imgContenttype)
{
string db = "server=localhost;database=test;uid=root;password=techsoft";
MySqlConnection conn = new MySqlConnection(db);
MySqlCommand cmd = new MySqlCommand("insert into image(img_name,img_file,img_type) values(?img_name,?img_file,?img_type)", conn);
//MySqlParameter param0 = new MySqlParameter("?img_id", MySqlDbType.Int16, 20);
//param0.Value = ;
//cmd.Parameters.Add(param0);
MySqlParameter param0 = new MySqlParameter("?img_name", MySqlDbType.VarChar, 45);
param0.Value = imgName;
cmd.Parameters.Add(param0);
// MySqlParameter param1 = new MySqlParameter("?img_file", MySqlDbType.VarChar, 45);
MySqlParameter param1 = new MySqlParameter("?img_file", MySqlDbType.LongBlob, 10);
param1.Value = imgbin;
cmd.Parameters.Add(param1);
MySqlParameter param2 = new MySqlParameter("?img_type", MySqlDbType.VarChar, 45);
param2.Value = imgContenttype;
cmd.Parameters.Add(param2);
conn.Open();
int num = cmd.ExecuteNonQuery();
conn.Close();
return num;
}
I have used binary writer to display. Can anybody suggest how to display images in fixed dimensions?
I would resize the images on the page being used to display them. Where are they being displayed?
or
I would resize the images at the time they are saved
Assuming your only challenge is to only scale the images(either before uploading or when retrieving them)...here is some code i use to get scaled dimensions for an image (to fit specific fixed dimensions)...you can stick this somewhere in an imaging class
Note that there are many approaches...
public static Size getScaledDimensions( Image img, Int32 maxW, Int32 maxH)
{
//check if image is already within desired dimensions
if (img.Height <= maxH & img.Width <= maxW)
{
Size orgsize = new Size(img.Width, img.Height);
return orgsize; // no need to rescale
}
else //proceed with rescaling
{
int finalH;
int finalW;
//use height/width ratio to determine our new dimensions
double hwRatio = (double)img.Height / (double)img.Width;
int newW = (int) (maxH/ hwRatio);
int newH = (int) (hwRatio * maxW);
//make sure we scale the right dimension
if (newW <= maxW) // scale width
{
finalH = maxH;
finalW = newW;
}
else
{ // scale height
finalH = newH;
finalW = maxW;
}//end if
Size newsize = new Size(finalW, finalH);
return newsize;
}
Thanks for all the support from rip and The_AlienCoder for their answers. I have found out answer to my own query.
We need to use streams to convert binary data from mysql database. Later graphic library should be used to load the streams. In the meantime we need to resize the image according to our need.
protected void Page_Load(object sender, EventArgs e){
//Create connection to mysql database.
MySqlConnection conn = new MySqlConnection(db);
conn.Open();
string s;
s = Session["t"].ToString();
string commantext = "select img_id,img_file,img_type,img_name from image where img_name='"+s+"'";
MySqlCommand cmd = new MySqlCommand(commantext,conn);
cmd.Parameters.Add("?img_id", MySqlDbType.Int32).Value = s;
//create datatable. GetData is a method to fetch the data.
DataTable dt = GetData(cmd);
//Get data from database to bytes.
Byte[] bytes = (Byte[])dt.Rows[0]["img_file"];
//Defining the size to display data.
int outputSize = 100;
if (bytes.Length > 0)
{
// Open a stream for the image and write the bytes into it
System.IO.MemoryStream stream = new System.IO.MemoryStream(bytes, true);
stream.Write(bytes, 0, bytes.Length);
Bitmap bmp = new Bitmap(stream);
Size new_size = new Size();
//resize based on the longer dimension
if (bmp.Width > bmp.Height)
{
new_size.Width = outputSize;
new_size.Height = (int)(((double)outputSize / (double)bmp.Width) * (double)bmp.Height);
}
else
{
new_size.Width = (int)(((double)outputSize / (double)bmp.Height) * (double)bmp.Width);
new_size.Height = outputSize;
}
Bitmap bitmap = new Bitmap(new_size.Width, new_size.Height, bmp.PixelFormat);
Graphics new_g = Graphics.FromImage(bitmap);
new_g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
new_g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
new_g.DrawImage(bmp, -1, -1, bitmap.Width + 1, bitmap.Height + 1);
bmp.Dispose();
bitmap.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
bitmap.Dispose();
new_g.Dispose();
stream.Close();
}
}
private DataTable GetData(MySqlCommand cmd)
{
DataTable dt = new DataTable();
//String strConnString = System.Configuration.ConfigurationManager .ConnectionStrings["conString"].ConnectionString;
MySqlConnection con = new MySqlConnection(db);
MySqlDataAdapter sda = new MySqlDataAdapter();
cmd.CommandType = CommandType.Text;
cmd.Connection = con;
try
{
con.Open();
sda.SelectCommand = cmd;
sda.Fill(dt);
return dt;
}
catch
{ return null;
}
finally
{ con.Close();
sda.Dispose();
con.Dispose();
}
}
}