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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;
namespace Payment
{
public partial class frmCustomer : Form
{
public frmCustomer()
{
InitializeComponent();
}
bool isDataSaved = true;
private void frmCustomer_Load(object sender, EventArgs e)
{
cboNames.Items.Add("Mike Smith");
cboNames.Items.Add("Nancy Jones");
}
private void frmCustomer_FormClosing(object sender, FormClosingEventArgs e)
{
if (isDataSaved == false) {
string msg = "This form contains unsaved data"
+ "\n\nDo you want to save it?";
DialogResult button =
MessageBox.Show(msg, "Customer",
MessageBoxButtons.YesNoCancel,
MessageBoxIcon.Warning);
if (button == DialogResult.Yes)
if (IsValidData())
this.SaveData();
else
e.Cancel = true;
if (button == DialogResult.Cancel)
e.Cancel = true;
}
}
private void btnSelectPayment_Click(object sender, EventArgs e)
{
Form payment = new frmPayment();
DialogResult selectedButton = payment.ShowDialog();
if (selectedButton == DialogResult.OK)
lblPayment.Text = (string)payment.Tag;
}
private void btnSave_Click(object sender, EventArgs e)
{
if (IsValidData())
SaveData();
}
private void btnExit_Click(object sender, EventArgs e)
{
this.Close();
}
private void lblPayment_TextChanged(object sender, EventArgs e)
{
isDataSaved = false;
}
private void cboNames_SelectedIndexChanged(object sender, EventArgs e)
{
isDataSaved = false;
lblPayment.Text = "";
}
private void SaveData()
{
cboNames.SelectedIndex = -1;
lblPayment.Text = "";
isDataSaved = true;
cboNames.Focus();
}
private bool IsValidData()
{
if (cboNames.SelectedIndex == -1) {
MessageBox.Show("You must select a customer",
"Entry Error");
return false;
}
if (lblPayment.Text == "") {
MessageBox.Show("You must enter a payment",
"Entry Error");
return false;
}
return true;
}
}
}
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