private void frmMain_Load(object sender, EventArgs e) // this block helps to load customers.txt when the form loads
{
FileStream fs;
StreamReader sr = null;
string line; // for reading
string[] fields; // line broken into fields
CustomerData cust;
string name; //customer name
int acctNo; //customer account num
string customerType; // type if residential, commercial or industrial
decimal charge;
if (radResidential.Checked)
{
customerType = "R";
}
else if (radCommercial.Checked)
{
customerType = "C";
}
else
{
customerType = "I";
}
try
{
fs = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Read);
sr = new StreamReader(fs);
// read data
while (!sr.EndOfStream) // while there are still products in the file
{
line = sr.ReadLine(); // read next line
fields = line.Split(','); // CSV file
name = fields[0];
customerType = fields[1];
acctNo = Convert.ToInt32(fields[2]);
charge = Convert.ToDecimal(fields[3]);
cust = new CustomerData(name, customerType, acctNo, charge);
customers.Add(cust);
}
DisplayCustomers();
}
catch (Exception ex)
{
MessageBox.Show("Error while reading products from file: " +
ex.Message, ex.GetType().ToString());
}
finally
{
if (sr != null)
{
sr.Close();
}
}
}
// calculate customer charge
private void btnCalculate_Click(object sender, EventArgs e)
{
int kWh = 0, peakKWh = 0, offPeaKWh = 0;
decimal chargeAmt = 0;
if (radResidential.Checked)
{
if (Validator.IsPresent(txtkWh1, "kWh") &&
Validator.IsNonNegativeInteger(txtkWh1, "kWh"))
{
kWh = Convert.ToInt32(txtkWh1.Text);
chargeAmt = CustomerData.ResidentialCharge(kWh);
}
}
else if (radCommercial.Checked)
{
if (Validator.IsPresent(txtkWh1, "Used kWh") &&
Validator.IsNonNegativeInteger(txtkWh1, "kWh"))
{
kWh = Convert.ToInt32(txtkWh1.Text);
chargeAmt = CustomerData.CommercialCharge(kWh);
}
}
else // must be industrial
{
if (Validator.IsPresent(txtkWh1, "Peak kWh") &&
Validator.IsNonNegativeInteger(txtkWh1, "Peak kWh") &&
Validator.IsPresent(txtkWh2, "Off-peak kWh") &&
Validator.IsNonNegativeInteger(txtkWh2, "Off-peak kWh"))
{
peakKWh = Convert.ToInt32(txtkWh1.Text);
offPeaKWh = Convert.ToInt32(txtkWh2.Text);
chargeAmt = CustomerData.IndustrialCharge(peakKWh, offPeaKWh);
}
}
// display charge
lblCharge.Text = chargeAmt.ToString();
}
// add information to the list and save the list to customers.txt
private void btnAdd_Click(object sender, EventArgs e)
{
string name;
int acctNo;
string customerType;
decimal charge;
//validations
if (Validator.IsPresent(txtCustName, "Name") &&
Validator.IsPresent(txtAcctNum, "Accout Number") &&
Validator.IsNonNegativeInteger(txtAcctNum, "Accout Number") &&
Validator.IsPresentlbl(lblCharge, "Calculate Charge"))
{
// assign values to objects
name = txtCustName.Text;
acctNo = Convert.ToInt32(txtAcctNum.Text);
charge = Convert.ToDecimal(lblCharge.Text);
if (radResidential.Checked)
{
customerType = "R";
}
else if (radCommercial.Checked)
{
customerType = "C";
}
else
{
customerType = "I";
}
CustomerData newCust = new CustomerData(name, customerType, acctNo, charge);
// add new product to the list
customers.Add(newCust);
// and refresh display
DisplayCustomers();
FileStream fs;
StreamWriter sw = null;
string line;
try
{
// open file for writing
fs = new FileStream(path, FileMode.Create, FileAccess.Write);
sw = new StreamWriter(fs);
// write all products to the file in form like:
foreach (CustomerData p in customers)
{
line = p.Name + "," + p.CustomerType + "," + p.AcctNo + "," + p.Charge; // CSV file
sw.WriteLine(line);
}
}
catch (Exception ex)
{
MessageBox.Show("Error while writing products to file: " +
ex.Message, ex.GetType().ToString());
}
finally
{
if (sw != null)
{
sw.Close();
}
}
txtCustName.Focus();
}
}