Object reference error

Question

        int CId = 0;
        

        private void button1_Click(object sender, EventArgs e)
        { 
            try
            {
                if (textBox1.Text == "" || textBox2.Text == "" || comboBox1.SelectedIndex == -1 || textBox3.Text == "")
                {
                    MessageBox.Show("Missing information");
                }
                else
                {
                    Con.Open();
                    SqlCommand cmd = new SqlCommand("INSERT INTO EventTbl(CName,CPhone,Events,Date) VALUES (@CN, @CP, @E, @D)",Con);
                    cmd.Parameters.AddWithValue("@CN", textBox1.Text);
                    cmd.Parameters.AddWithValue("@CP", textBox2.Text);
                    cmd.Parameters.AddWithValue("@E", comboBox1.SelectedValue.ToString());
                    cmd.Parameters.AddWithValue("@D", textBox3.Text);
                    cmd.BeginExecuteNonQuery();
                    Con.Close();
                    MessageBox.Show("Record Entered Sucessfully");
                    DisplayEvent();

                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            finally { Con.Close(); }
        }
What error is found is this code i have an eoor of object reference is not set to an instance of an object

Answer 1

The error "object reference is not set to an instance of an object" occurs when you try to use an object that has not been initialized. In the provided code, it is possible that the Con object has not been initialized before it is used in the try block. To resolve this error, you should initialize the Con object before using it.

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References:

• Open SQL Server database by using SQL Server .NET Data Provider with Visual Basic .NET