Image Retrieval and Update in c#

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Hello in my project am updating the image by replacing the existing image .When i tried to update it by Student Id (SID) (debugging) it shows an error that "input string was not in a correct format".How to solve this?

My Code

C#

private void btn_Update_Image_Click(object sender, EventArgs e)
        {
            try
            {
                

                if (txtSearchID.Text == "")
                {
                    errorProvider1.SetError(txtsid, "Enter a valid Student Id ");
                    txtsid.Focus();
                    return;
                }




                string connectionstring = ConfigurationManager.ConnectionStrings["ConStr"].ConnectionString;
                Image_SqlCo = new SqlConnection(connectionstring);
                this.Image_SqlCo.Open();
                if (Image_sqlcmd.Parameters.Count == 0)
                {
                    this.Image_sqlcmd.CommandText = "UPDATE tbl_ImageData SET Picture=@Picture where SID=@SID";
                    this.Image_sqlcmd.Parameters.Add("@SID", System.Data.SqlDbType.Int, 4);
                    //this.Image_sqlcmd.Parameters.Add("@Name", System.Data.SqlDbType.VarChar, 50);
                   this.Image_sqlcmd.Parameters.Add("@Picture", System.Data.SqlDbType.Image);

                }
                this.Image_sqlcmd.Parameters[Convert.ToInt32("@SID")].Value =Convert.ToInt32(this.txtsid.Text);
                //this.Image_sqlcmd.Parameters["@Name"].Value = this.txtImagePath.Text;
                this.Image_sqlcmd.Parameters["@Picture"].Value = this.m_barrImg;
                Image_sqlcmd.Connection = Image_SqlCo;
                int iResult = this.Image_sqlcmd.ExecuteNonQuery();
                MessageBox.Show("Photo Updated");
                //btn_SaveImage.Enabled = false;
                //btn_Upload.Enabled = false;
            }
            catch (Exception ex1)
            {
                MessageBox.Show(ex1.ToString());
            }

            finally
            {
                this.Image_SqlCo.Close();
            }
        }

Posted 11-Nov-13 9:19am

Member 10370658

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♥…ЯҠ…♥ 12-Nov-13 0:17am

In which line you got this error?

2 solutions

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♥…ЯҠ…♥ · Accepted Answer · 2013-11-11T18:31:00

Solution 2

Hi,

You are trying to convert string value to Int32, that is not quite possible.

For example see this snipper

C#

string temp = string.Empty;
temp = temp + " Test string ";
int val = Convert.ToInt32(temp); //Here you will get the error

In your code, problematic line is

this.Image_sqlcmd.Parameters[Convert.ToInt32("@SID")].Value =Convert.ToInt32(this.txtsid.Text);

So you have to decide should I need to convert it to Int or not....
Your call.

Hope this helps you a bit.

Regards,
RK

Posted 11-Nov-13 18:31pm

♥…ЯҠ…♥

Updated 11-Nov-13 18:33pm

v2

Comments

Member 10370658 12-Nov-13 1:54am

hello i have changed my code
string SID = txtsid.Text;
this.Image_sqlcmd.Parameters.Add("@SID",SID);
this.Image_sqlcmd.Parameters.Add("@Picture", System.Data.SqlDbType.Image);

now its working fine....Noconversion problem..:)

♥…ЯҠ…♥ 12-Nov-13 2:29am

Am glad its working fine.....

**Orcun Iyigun** · Accepted Answer · 2013-11-11T09:57:00

Solution 1

The error is pretty self explanatory. Basically the exception you are getting means the value you are trying to convert is not accepted. So here is an example to clarify it for you.

C#

string strInput = "12a";

If you try to convert this to a number such as:

C#

int intTest = Convert.ToInt32(strInput);

You will get the same exception. So debug your code and stop at the line where you get the exception and check the value you are getting.

Good luck,
OI

Posted 11-Nov-13 9:57am

Orcun Iyigun

Updated 11-Nov-13 19:02pm

v3

Comments

Sergey Alexandrovich Kryukov 11-Nov-13 18:19pm

You certainly messed up something. You can always call ToString(), for any object. Maybe you meant to write something else.
—SA

Orcun Iyigun 12-Nov-13 1:02am

Totally right. I have corrected it. Thank you for the warning

Sergey Alexandrovich Kryukov 12-Nov-13 1:10am

Someone already voted 1, probably before you fixed your post. Anyway, I'm glad that I decided not to down-vote it, because I did not believe that it could be your "real" mistake. I voted 4. (In particular, I think you should have mentioned Parse/TryParse methods are primary way of parsing.)
Cheers,
—SA

Orcun Iyigun 12-Nov-13 1:36am

Thank you Sergey, I wish I can upvote your comment too. You are right about using Parse/TryParse methods.

Sergey Alexandrovich Kryukov 12-Nov-13 2:23am

:-)