error in calculation

Question

Hello guys

 

Please i need help in finding the cause of this error. I got this error when i clicked total button to calculate.

 

thanks 

 

 

 

 

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;

using System.Data.SqlClient;

namespace NSPM_Sales_Invoice

{

public partial class frmNewBill : Form

{

SqlConnection con = new SqlConnection(Properties.Settings.Default.NSPM_Sales_InvoiceCon);

SqlCommand cmd;

public frmNewBill()

{

InitializeComponent();

txtDeleteUpdate.Visible = false;

}

private void textBox1_TextChanged(object sender, EventArgs e)

{

}

private void panel1_Paint(object sender, PaintEventArgs e)

{

}

private void tableLayoutPanel1_Paint(object sender, PaintEventArgs e)

{

}

private void frmNewBill_Load(object sender, EventArgs e)

{

cmbDescription.Select();

cmbDescription.Items.Clear();

con.Open();

cmd = con.CreateCommand();

cmd.CommandType = CommandType.Text;

cmd.CommandText = "Select ProName from tbl_Products order by ProName asc";

cmd.ExecuteNonQuery();

DataTable dt = new DataTable();

SqlDataAdapter da = new SqlDataAdapter(cmd);

da.Fill(dt);

foreach (DataRow dr in dt.Rows)

{

cmbDescription.Items.Add(dr["ProName"].ToString());

}

con.Close();

dataGridView1.Columns[5].Visible = false;

dataGridView1.Columns[6].Visible = false;

}

private void btnAdd_Click(object sender, EventArgs e)

{

if (cmbDescription.Text == "")

{

MessageBox.Show("Description is Empty");

}

else if (txtQuantity.Text == "")

{

MessageBox.Show("Quantity is Empty");

}

else if (txtUnitPrice.Text == "")

{

MessageBox.Show("Unit Price is Empty");

}

else if (txtJobNo.Text == "")

{

MessageBox.Show("JobNo is Empty");

if (txtDeleteUpdate.Text == "")

{

int row = 0;

dataGridView1.Rows.Add();

row = dataGridView1.Rows.Count - 1;

dataGridView1["Description", row].Value = cmbDescription.Text;

dataGridView1["Quantity", row].Value = txtQuantity.Text;

dataGridView1["UnitPrice", row].Value = txtUnitPrice.Text;

dataGridView1["GoodValue", row].Value = txtGoodValue.Text;

dataGridView1["JobNo", row].Value = txtJobNo.Text;

dataGridView1["Date", row].Value = dateTimePicker1.Value.ToString("yyyy-MM-dd");

dataGridView1.Refresh();

cmbDescription.Focus();

if (dataGridView1.Rows.Count > 0)

{

dataGridView1.CurrentCell = dataGridView1.Rows[dataGridView1.Rows.Count - 1].Cells[1];

}

}

else

{

btnAdd.Text = "UPDATE";

int i = 0;

DataGridViewRow row = dataGridView1.Rows[i];

row.Cells[1].Value = cmbDescription.Text;

row.Cells[2].Value = txtQuantity.Text;

row.Cells[3].Value = txtUnitPrice.Text;

row.Cells[4].Value = txtGoodValue.Text;

row.Cells[5].Value = txtJobNo.Text;

btnAdd.Text = "ADD";

}

cleartextbox();

gridGoodValue();

}

}

private void dataGridView1_RowPostPaint(object sender, DataGridViewRowPostPaintEventArgs e)

{

this.dataGridView1.Rows[e.RowIndex].Cells[0].Value = (e.RowIndex + 1).ToString();

}

int i;

private void dataGridView1_CellDoubleClick(object sender, DataGridViewCellEventArgs e)

{

i = e.RowIndex;

DataGridViewRow row = dataGridView1.Rows[i];

cmbDescription.Text = row.Cells[1].Value.ToString();

txtQuantity.Text = row.Cells[2].Value.ToString();

txtUnitPrice.Text = row.Cells[3].Value.ToString();

txtGoodValue.Text = row.Cells[4].Value.ToString();

txtJobNo.Text = row.Cells[5].Value.ToString();

txtDeleteUpdate.Text = row.Cells[0].Value.ToString();

btnAdd.Text = "UPDATE";

}

private void btnDelete_Click(object sender, EventArgs e)

{

if (txtDeleteUpdate.Text == "")

{

MessageBox.Show("Select Product to Delete");

}

else

{

foreach (DataGridViewRow row in dataGridView1.SelectedRows)

{

if (!row.IsNewRow) dataGridView1.Rows.Remove(row);

}

}

btnAdd.Text = "ADD";

gridGoodValue();

cleartextbox();

}

public void cleartextbox()

{

cmbDescription.Text = "";

txtQuantity.Text = "";

txtUnitPrice.Text = "";

txtGoodValue.Text = "";

txtJobNo.Text = "";

txtDeleteUpdate.Text = "";

}

public void CalGoodValue()

{

double a1, b1, i;

double.TryParse(txtUnitPrice.Text, out a1);

double.TryParse(txtQuantity.Text, out b1);

i = a1 * b1;

if (1 > 0)

{

txtGoodValue.Text = i.ToString("C").Remove(0, 1);

}

}

private void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)

{

}

private void txtQuantity_Leave(object sender, EventArgs e)

{

CalGoodValue();

}

private void txtQuantity_TextChanged(object sender, EventArgs e)

{

}

private void txtUnitPrice_Leave(object sender, EventArgs e)

{

CalGoodValue();

}

public void gridGoodValue()

{

double sum = 0;

for (int i = 0; i < dataGridView1.Rows.Count; ++i)

{

sum += Convert.ToDouble(dataGridView1.Rows[i].Cells[4].Value);

}

txtTotalGoodValue.Text =sum.ToString();

}

public void VatCal()

{

const double VatRate = 0.05;

double TotalGoodValue = Double.Parse(txtTotalGoodValue.Text);

double Vat = TotalGoodValue * VatRate;

double Total = TotalGoodValue + Vat;

txtVat.Text = Vat.ToString();

txtTotal.Text = Total.ToString();

}

public void StampDuty()

{

double a2, b2, c2, d2, e2, i;

double.TryParse(txtTotalGoodValue.Text, out a2);

double.TryParse(txtVat.Text, out b2);

double.TryParse(txtStampDuty.Text, out c2);

double.TryParse(txtDeliveryCharges.Text, out d2);

double.TryParse(txtOtherCharges.Text, out e2);

i = a2 + b2 + c2 + d2 + e2;

if (i > 0)

{

txtTotal.Text = i.ToString("C").Remove(0, 1);

}

}

private void txtValue_TextChanged(object sender, EventArgs e)

{

}

private void txtTotalGoodValue_TextChanged(object sender, EventArgs e)

{

VatCal();

}

private void txtVat_TextChanged(object sender, EventArgs e)

{

VatCal();

}

private void txtStampDuty_Leave(object sender, EventArgs e)

{

StampDuty();

}

private void txtDeliveryCharges_Leave(object sender, EventArgs e)

{

StampDuty();

}

private void txtOtherCharges_Leave(object sender, EventArgs e)

{

StampDuty();

}

private void btnSave_Click(object sender, EventArgs e)

{

if (dataGridView1.Rows.Count < 1)

{

MessageBox.Show("Add Minimum of one Product to Bill");

}

else

{

//Save Leader data

con.Open();

cmd = new SqlCommand("Insert Into Tbl_HeaderData (JobNo,Date,GoodValue,StampDuty,Vat,DeliveryCharges,OtherCharges,Total) values ('" + txtJobNo.Text + "','" +dateTimePicker1.Value.ToString("yyyy-MM-dd")+ "','" + txtGoodValue.Text + "','" + txtVat.Text + "','" + txtStampDuty.Text + "','" + txtDeliveryCharges.Text + "','" + txtOtherCharges.Text + "','" + txtTotal.Text + "')", con);

cmd.ExecuteNonQuery();

//Save row data

for(int i = 0; i < dataGridView1.Rows.Count;i++)

{

SqlCommand cmd1 = new SqlCommand("Insert Into Tbl_RowData(SINO,Description,Price,Quantity,Value,JobNo) values('" + dataGridView1.Rows[i].Cells[0].Value.ToString() + "','" + dataGridView1.Rows[i].Cells[1].Value.ToString() + "','" + dataGridView1.Rows[i].Cells[2].Value.ToString() + "','" + dataGridView1.Rows[i].Cells[3].Value.ToString() + "','" + dataGridView1.Rows[i].Cells[4].Value.ToString() + "','" + dataGridView1.Rows[i].Cells[5].Value.ToString() + "')", con);

cmd1.ExecuteNonQuery();

}

MessageBox.Show("Bill Saved");

con.Close();

cleartextbox();

txtTotalGoodValue.Text = "";

txtVat.Text = "";

txtStampDuty.Text = "";

txtDeliveryCharges.Text = "";

txtOtherCharges.Text = "";

txtTotal.Text = "";

cmbDescription.Select();

}

}

}

}