this code gives me an exception "Object reference not set to an instance of an object" when i try to execute this sql query

Question

I dynamically create controls which I need
Here is the code

public void cmdButton1_OnClick(object sender, EventArgs e)
{

        Label myLabel = new Label();
        myLabel.ID = "lblNameL" + i.ToString();
        myLabel.Text = "Трите имена на латиница ";
        TextBox myTextBox1 = new TextBox();
        myTextBox1.ID = "txtNameL" + i.ToString();
        Page.FindControl("form1").Controls.Add(myLabel);
        Page.FindControl("form1").Controls.Add(myTextBox1);

        Label mylabel2 = new Label();
        mylabel2.ID = "lblNameK" + i.ToString();
        mylabel2.Text = "Трите имена на кирилица";
        TextBox myTextBox2 = new TextBox();
        myTextBox2.ID = "txtNameK" + i.ToString();
        Page.FindControl("form1").Controls.Add(mylabel2);
        Page.FindControl("form1").Controls.Add(myTextBox2);
}

And here i try to execute sql query so that I can insert what's written the textbox txbNameK into table Tourist the exception is in the row cmd.Parameters.add

public void cmdInsert_OnClick(object sender, EventArgs e)
{

        TextBox tx888 = (TextBox)FindControl("txtNameK" + i.ToString());
        TextBox tx99 = (TextBox)FindControl("txtNameL" + i.ToString());

        string insertSQL = "INSERT INTO Tourist ( Name_kir, Name_lat) VALUES (@Name_kir, @Name_lat, )";

        string connectionString = "Data Source = localhost\\SQLExpress;Initial Catalog=Pubs;Integrated Security=SSPI";
        SqlConnection con = new SqlConnection(connectionString);
        SqlCommand cmd = new SqlCommand(insertSQL, con);
        cmd.Parameters.AddWithValue("@Name_kir",tx888);
        cmd.Parameters.AddWithValue("@Name_lat", tx99);

        int added = 0;
        try
        {
            con.Open();
            added = cmd.ExecuteNonQuery();
            lblResult.Text = added.ToString() + "records added";

        }
        catch (Exception ex)
        {
            lblResult.Text = ex.Message;
        }
        finally
        {
            con.Close();

        }
    }
}

You've never checked whether you actually found the textbox, my money's on that being null. Further, I assume you actually mean to pass the "Text" property of the textbox, not the whole thing? — sybkar
– sybkar, Commented Nov 21, 2012 at 13:05

Prashant Lakhlani · Accepted Answer · 2012-11-21 13:15:11Z

1

Two things:

TextBox tx888 = (TextBox)FindControl("txtNameK" + i.ToString());
TextBox tx99 = (TextBox)FindControl("txtNameL" + i.ToString());
if(tx888 == null)
    return;
if(tx99 == null)
    return;

Above will check if your texbox is null or not And another thing is:

cmd.Parameters.AddWithValue("@Name_kir",tx888.Text);
cmd.Parameters.AddWithValue("@Name_lat", tx99.Text);

answered Nov 21, 2012 at 13:15

Prashant Lakhlani

5,8065 gold badges27 silver badges39 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Tania Marinova Over a year ago

HI! Thank you for your answer! I've tried this before - but still the exception stays!

Tania Marinova Over a year ago

now everything is right! I just had some problems with the query!

Shantanu Gupta · Accepted Answer · 2012-11-21 13:23:22Z

0

Object reference exception always occurs whenever null object is trying to access any value. eg..

Code below will work fine.

Exception ex = new Exception()
Textbox1.Text = ex.Message;

Code below will throw an exception

Exception ex= null;    //one and the same thing

Textbox1.Text = ex.Message;     //Object reference not set....exception will be raised since ex is null

This is what is happening in your code. Try to place a breakpoint and debug it. For best practice always check for an object for null as suggested by Prashant.

answered Nov 21, 2012 at 13:23

Shantanu Gupta

21.2k56 gold badges187 silver badges294 bronze badges

Collectives™ on Stack Overflow

this code gives me an exception "Object reference not set to an instance of an object" when i try to execute this sql query

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related