I have a predicament! I don't know where I should put my variables in a C# Windows Forms Application. For example, in my WFA project I have a list of my own datatype object called "Item" and at the moment I've had to make it global, however, I understand global isn't the best of practises. Because I come from a C++ background I'd always create my variables in int main() and pass them to functions where needed. I honestly can't find an answer anywhere. Many thanks to anyone who can assist me.
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 Sales_Calculator
{
public partial class Form1 : Form
{
//Should my list<Item> go here or is there a better place for it?
List<Item> objItems = new List<Item>();
public Form1()
{
InitializeComponent();
}
public class Item
{
private string m_sItemName;
private double m_dItemPrice;
private int m_iQuantitySold;
public Item(string sItemName, double dItemPrice, int iQuantitySold)
{
m_sItemName = sItemName;
m_dItemPrice = dItemPrice;
m_iQuantitySold = iQuantitySold;
}
public string Name
{
get { return m_sItemName; }
set { m_sItemName = value; }
}
public int QuantitySold
{
get { return m_iQuantitySold; }
set { m_iQuantitySold = value; }
}
public double Price
{
get { return m_dItemPrice; }
set { m_dItemPrice = value; }
}
}
bool DoesItemNameExist(string sName)
{
return (objItems.Find(delegate (Item objItem){return sName == objItem.Name;}) != null) ? true : false;
}
private Item HighestSellingItem()
{
int MaxQuantitySold = objItems.Max(objItem => objItem.QuantitySold);
return objItems.Find(delegate (Item objItem) {
return objItem.QuantitySold == MaxQuantitySold;
});
}
private double Average()
{
int iTotal = 0;
objItems.ForEach(delegate (Item objItem)
{
iTotal += objItem.QuantitySold;
});
double dAverage = iTotal / objItems.Count;
return dAverage;
}
private void label1_Click(object sender, EventArgs e)
{
}
private void AddToDataGridView(object sender)
{
dgvItems.Rows.Add(objItems.Count, objItems.Last().Name, objItems.Last().QuantitySold, objItems.Last().Price);
}
void ClearTextBoxes()
{
txtItemName.Clear();
txtItemPrice.Clear();
txtQuantitySold.Clear();
}
void AddItemToList()
{
string sItemName = "";
if (DoesItemNameExist(sItemName = Convert.ToString(txtItemName.Text)))
{
MessageBox.Show("You can't have that name, it already exists!");
txtItemName.Clear();
return;
}
double dItemPrice = Convert.ToDouble(txtItemPrice.Text);
int iQuantitySold = Convert.ToInt32(txtQuantitySold.Text);
Item objItem = new Item(sItemName, dItemPrice, iQuantitySold);
objItems.Add(objItem);
MessageBox.Show("You have added an item!");
ClearTextBoxes();
}
private void button1_Click(object sender, EventArgs e)
{
try
{
AddItemToList();
AddToDataGridView(sender);
lblAverageQuantitySold.Text = Average().ToString();
lblExistingItems.Text = objItems.Count.ToString();
}
catch (Exception ex)
{
MessageBox.Show("You have inputted incorrectly!", "Invalid", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
dvgHighestSellingItem.Rows.Clear();
dvgHighestSellingItem.Rows.Add(HighestSellingItem().Name);
}
private void contextMenuStrip1_Opening(object sender, CancelEventArgs e)
{
}
}
}
