VIBlend DataGridView for WinForms allows you to set the grid cells' source to Virtual mode. There are two steps to setup Virtual mode:
1. Set the cells' data source to Virtual. You can do that for a specific cell as well as for all cells under a row or a column:
vDataGridView1.CellsArea.SetCellDataSource(column, GridCellDataSource.Virtual);
2. Implement a GridCellValueNeeded event handler. Whenever the data grid renders a cell it will raise the GridCellValueNeeded event:
vDataGridView1.GridCellValueNeeded += new
vDataGridView.GridCellValueNeededEventHandler(DataGridView1_GridCellValueNeeded);
void DataGridView1_GridCellValueNeeded(object sender, GridCellValueNeededEventArgs args)
{
args.Value = "Some text";
}
Here's a complete example which creates a list of 50,000 rows and sets up the grid in virtual mode:
using System;
using System.Collections.Generic;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using VIBlend.WinForms.Controls;
using VIBlend.WinForms.DataGridView;
using VIBlend.Utilities;
namespace VirtualModeDemo
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
public class EmployeeSales
{
public EmployeeSales(string Name, DateTime Date, int ProductId, int Quantity)
{
this.Name = Name;
this.Date = Date;
this.ProductId = ProductId;
this.Quantity = Quantity;
}
#region Private Members
private string _name;
private DateTime _date;
private int _productid;
private int _quantity;
#endregion
#region Properties
public string Name
{
get { return _name; }
set { _name = value; }
}
public DateTime Date
{
get { return _date; }
set { _date = value; }
}
public string ProductName
{
get { return productNames[_productid, 0]; }
}
public double SalesAmount
{
get { return (double)_quantity * UnitPrice; }
}
public double UnitPrice
{
get
{
double unitPrice = double.Parse(productNames[_productid, 1]);
return unitPrice;
}
}
public int Quantity
{
get { return _quantity; }
set { _quantity = value; }
}
public int ProductId
{
get { return _productid; }
set { _productid = value; }
}
#endregion
}
// Implement the cell value needed event handler
void DataGridView1_GridCellValueNeeded(object sender, GridCellValueNeededEventArgs args)
{
int rowIndex = int.Parse(args.RowItem.Caption) - 1;
if (args.ColumnItem.Caption == "Employee Name")
args.CellValue = lst[rowIndex].Name;
else if (args.ColumnItem.Caption == "Transaction Date")
args.CellValue = lst[rowIndex].Date;
else if (args.ColumnItem.Caption == "Product Name")
args.CellValue = lst[rowIndex].ProductName;
else if (args.ColumnItem.Caption == "Quantity")
args.CellValue = lst[rowIndex].Quantity;
else if (args.ColumnItem.Caption == "Unit Price")
args.CellValue = lst[rowIndex].UnitPrice;
else if (args.ColumnItem.Caption == "Transaction Amount")
args.CellValue = lst[rowIndex].SalesAmount;
}
#region Data
string[] firstNames = new string[]
{
"Andrew",
"Nancy",
"Shelley",
"Regina",
"Yoshi",
"Antoni",
"Mayumi",
"Ian",
"Peter",
"Lars",
"Petra",
"Martin",
"Sven",
"Elio",
"Beate",
"Cheryl",
"Michael",
"Guylène"
};
string[] lastNames = new string[]
{
"Fuller",
"Davolio",
"Burke",
"Murphy",
"Nagase",
"Saavedra",
"Ohno",
"Devling",
"Wilson",
"Peterson",
"Winkler",
"Bein",
"Petersen",
"Rossi",
"Vileid",
"Saylor",
"Björn",
"Nodier"
};
static string[,] productNames = new string[,]
{
{"Black Tea", "1.95"},
{"Green Tea", "1.95"},
{"Caffe Espresso", "1.45"},
{"Doubleshot Espresso", "1.75"},
{"Caffe Latte", "2.25"},
{"White Chocolate Mocha", "2.35"},
{"Cramel Latte", "2.35"},
{"Caffe Americano", "1.65"},
{"Cappuccino", "2.10"},
{"Espresso Truffle", "2.45"},
{"Espresso con Panna", "1.81"},
{"Peppermint Mocha Twist", "1.99"}
};
#endregion
List<EmployeeSales> lst = new List<EmployeeSales>();
private void Form1_Load(object sender, EventArgs e)
{
vDataGridView1.RowsHierarchy.AllowResize = true;
vDataGridView1.RowsHierarchy.AllowDragDrop = false;
vDataGridView1.ColumnsHierarchy.AllowResize = true;
vDataGridView1.ColumnsHierarchy.AllowDragDrop = false;
vDataGridView1.SelectionMode = vDataGridView.SELECTION_MODE.FULL_ROW_SELECT;
vDataGridView1.MultipleSelectionEnabled = true;
vDataGridView1.GridCellValueNeeded += new vDataGridView.GridCellValueNeededEventHandler(DataGridView1_GridCellValueNeeded);
const int rowsToLoad = 50000;
// Generate test data
Random rand = new Random();
for (int i = 0; i < rowsToLoad; i++)
{
int productId = rand.Next(0, productNames.Length / 2 - 1);
int quantity = rand.Next(1, 5);
lst.Add(new EmployeeSales(
string.Format("{0} {1}", firstNames[rand.Next(0, firstNames.Length - 1)], lastNames[rand.Next(0, lastNames.Length - 1)]),
DateTime.Now.AddDays(-rand.Next(10, 100)),
productId,
quantity)
);
}
BindGridVirtualMode();
}
private void BindGridVirtualMode()
{
Cursor.Current = Cursors.WaitCursor;
vDataGridView1.RowsHierarchy.Items.Clear();
vDataGridView1.RowsHierarchy.SummaryItems.Clear();
vDataGridView1.ColumnsHierarchy.Items.Clear();
vDataGridView1.ColumnsHierarchy.SummaryItems.Clear();
vDataGridView1.CellsArea.CellFormatting.ClearFormatProviders();
vDataGridView1.CellsArea.CellFormatting.ClearFormatSettings();
vDataGridView1.CellsArea.CellFormatting.SetFormatter("defaultNumberFormatter", null, "{0:#,###.####}");
#region Prepare the grid columns
vDataGridView1.ColumnsHierarchy.Fixed = true;
vDataGridView1.ColumnsHierarchy.Items.Add("Employee Name");
vDataGridView1.ColumnsHierarchy.Items.Add("Transaction Date");
vDataGridView1.ColumnsHierarchy.Items.Add("Product Name");
vDataGridView1.ColumnsHierarchy.Items.Add("Quantity");
vDataGridView1.ColumnsHierarchy.Items.Add("Unit Price");
vDataGridView1.ColumnsHierarchy.Items.Add("Transaction Amount");
// Set the cells data source to Virtual for all columns
foreach (HierarchyItem column in vDataGridView1.ColumnsHierarchy.Items)
vDataGridView1.CellsArea.SetCellDataSource(column, GridCellDataSource.Virtual);
vDataGridView1.CellsArea.CellFormatting.ClearFormatProviders();
vDataGridView1.CellsArea.CellFormatting.ClearFormatSettings();
vDataGridView1.CellsArea.CellFormatting.SetFormatter("dateFormatter", new System.Globalization.DateTimeFormatInfo(), "{0:dd-MMM-yyyy}");
vDataGridView1.CellsArea.CellFormatting.SetFormatter("dollarFormatter", null, "${0:#.##}");
vDataGridView1.CellsArea.CellFormatting.SetCellFormatting(vDataGridView1.ColumnsHierarchy.Items[1], "dateFormatter");
vDataGridView1.CellsArea.CellFormatting.SetCellFormatting(vDataGridView1.ColumnsHierarchy.Items[4], "dollarFormatter");
vDataGridView1.CellsArea.CellFormatting.SetCellFormatting(vDataGridView1.ColumnsHierarchy.Items[5], "dollarFormatter");
vDataGridView1.ColumnsHierarchy.AutoResize();
#endregion
#region Prepare the grid rows
for (int i = 0; i < lst.Count; i++)
vDataGridView1.RowsHierarchy.Items.Add((i + 1).ToString());
vDataGridView1.RowsHierarchy.SetColumnWidth(0, 30);
vDataGridView1.RowsHierarchy.Fixed = true;
#endregion
vDataGridView1.Refresh();
Cursor.Current = Cursors.Default;
}
}
}
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