Good day!In this article, I will describe the creation of my elements for C # Windows Form.For an example I will create the table with all DataGridView functionality. We will move on to our elements later. We will create the first element into several lessons. In this lesson we will draw from the table drawing, and also: creation of columns, rows, cells.For writing we will use .Net FrameWork 4.7.x, the Visual Studio 2019 development environment.First of all, we will create a regular Windows Form project. I think no need to show it. And only then we create the project “Library of Windows Form Controls” (Let's call it CustomControl).Next, we will create a UserControl.cs file. We delete it and create the usual class TableCustoms.cs. Our class will inherit from the Control class.Further in the same file we will create some more classes, namely: Column, Row, Cell. Let's consider each separately. Let's start with Column: [Serializable]
public class Column
{
public string Name { get; set; } = "NameColumn";
public string Caption { get; set; } = "CaptionColumn";
public int Width { get; set; } = 100;
public Color Back { get; set; } = Color.White;
public Column()
{
}
}
Row Class: [Serializable]
public class Row
{
public int Heigth { get; set; } = 20;
public List<Cell> Cells { get; set; } = new List<Cell>();
public Row()
{
}
public Row(List<Cell> cells)
{
Cells = cells;
}
}
Cell class (To support copying, add the ICloneable interface): [Serializable]
public class Cell : ICloneable
{
public object Value { get; set; } = null;
public Cell()
{
}
public object Clone()
{
return MemberwiseClone();
}
}
Now set up our main TableCustoms class: public class TableCustoms : Control
{
#region
public ObservableCollection<Column> Columns { get; set; } = new ObservableCollection<Column>();
private ObservableCollection<Row> rows = new ObservableCollection<Row>();
private int countRow = 0;
#endregion
#region
public int CountRow
{
get { return countRow; }
set
{
if (value > countRow)
{
int iteration = value - countRow;
for (int i = 0; i < iteration; i++)
{
rows.Add(new Row());
}
}
if (value < countRow)
{
int iteration = countRow - value;
for (int i = 0; i < iteration; i++)
{
rows.Remove(rows[rows.Count - 1]);
}
}
countRow = value;
}
}
public ObservableCollection<Row> Rows
{
get { return rows; }
set { }
}
public int ColumnHeaderHeigth { get; set; } = 20;
public int RowHeaderWidth { get; set; } = 20;
public Color ColumnHeaderBack { get; set; } = SystemColors.Control;
public Color BorderColor { get; set; } = Color.Black;
public bool NumerableRows { get; set; } = false;
#endregion
private void EditColumn()
{
}
private void EditRows()
{
if (countRow < rows.Count)
{
rows[rows.Count - 1].Cells = CreatCells(Columns.Count);
countRow++;
}
if (CountRow > rows.Count)
{
countRow--;
}
}
private List<Cell> CreatCells(int Count)
{
List<Cell> result = new List<Cell>();
for (int i = 0; i < Count; i++)
{
result.Add(new Cell());
}
return result;
}
public TableCustoms()
{
rows.CollectionChanged += (e, v) => EditRows();
Columns.CollectionChanged += (e, v) => EditColumn();
BackColor = SystemColors.AppWorkspace;
PanelTable panelTable = new PanelTable(this);
panelTable.Dock = DockStyle.Fill;
Controls.Add(panelTable);
}
}
In order for us to have scrollbars we need to use ScrollableControl, therefore we will create the PanelTable class, inherit ScrollableControl and place it on Control (in the next lesson I will explain why we create two different controls, and do not use ScrollableControl right away): internal class PanelTable : ScrollableControl
{
private TableCustoms BParent;
public PanelTable(TableCustoms bParent)
{
HScroll = true;
VScroll = true;
AutoScroll = true;
BParent = bParent;
}
protected override void OnPaint(PaintEventArgs e)
{
Matrix m = new Matrix();
m.Translate(this.AutoScrollPosition.X, this.AutoScrollPosition.Y, MatrixOrder.Append);
e.Graphics.Transform = m;
Graphics graf = e.Graphics;
int maxWidth = 0;
int maxHeight = 0;
foreach (Column item in BParent.Columns)
{
maxWidth += item.Width;
}
foreach (Row item in BParent.Rows)
{
maxHeight += item.Heigth;
}
AutoScrollMinSize = new Size(maxWidth + 100, maxHeight + 100);
graf.Clear(BParent.BackColor);
DrawHeaderColumns(graf);
DrawHeaderRows(graf);
DrawCells(graf);
base.OnPaint(e);
}
private void DrawHeaderColumns(Graphics graf)
{
int x = 2;
Rectangle rect;
rect = new Rectangle(x, 1, BParent.RowHeaderWidth, BParent.ColumnHeaderHeigth);
graf.DrawRectangle(new Pen(BParent.BorderColor), rect);
graf.FillRectangle(new SolidBrush(BParent.ColumnHeaderBack), rect);
x += BParent.RowHeaderWidth + 1;
foreach (Column item in BParent.Columns)
{
rect = new Rectangle(x, 1, item.Width, BParent.ColumnHeaderHeigth);
graf.DrawRectangle(new Pen(BParent.BorderColor), rect);
graf.FillRectangle(new SolidBrush(BParent.ColumnHeaderBack), rect);
if (item.Caption.Length != 0)
{
StringFormat sf = new StringFormat();
sf.Alignment = StringAlignment.Center;
sf.LineAlignment = StringAlignment.Center;
graf.DrawString(item.Caption, new Font("Times", 9), Brushes.Black, rect, sf);
}
x += item.Width + 1;
}
}
private void DrawHeaderRows(Graphics graf)
{
int y = 1;
int i = 0;
Rectangle rect;
y += BParent.RowHeaderWidth + 1;
foreach (Row item in BParent.Rows)
{
rect = new Rectangle(2, y, BParent.RowHeaderWidth, item.Heigth);
graf.DrawRectangle(new Pen(BParent.BorderColor), rect);
graf.FillRectangle(new SolidBrush(BParent.ColumnHeaderBack), rect);
if (BParent.NumerableRows)
{
StringFormat sf = new StringFormat();
sf.Alignment = StringAlignment.Center;
sf.LineAlignment = StringAlignment.Center;
graf.DrawString(i.ToString(), new Font("Times", 9), Brushes.Black, rect, sf);
}
i++;
y += item.Heigth + 1;
}
}
private void DrawCells(Graphics graf)
{
int x = 2 + BParent.RowHeaderWidth + 1;
int y = 2 + BParent.ColumnHeaderHeigth;
Rectangle rect;
int i = 0;
foreach (Row itemRow in BParent.Rows)
{
foreach (Column itemColumn in BParent.Columns)
{
rect = new Rectangle(x, y, itemColumn.Width, itemRow.Heigth);
graf.DrawRectangle(new Pen(BParent.BorderColor), rect);
graf.FillRectangle(new SolidBrush(Color.White), rect);
if (itemRow.Cells[i].Value != null)
{
StringFormat sf = new StringFormat();
sf.Alignment = StringAlignment.Center;
sf.LineAlignment = StringAlignment.Center;
graf.DrawString(itemRow.Cells[i].Value.ToString(), new Font("Times", 9), Brushes.Black, rect, sf);
}
x += itemColumn.Width + 1;
i++;
}
i = 0;
y += itemRow.Heigth + 1;
x = 2 + BParent.RowHeaderWidth + 1;
}
}
}
After that, “Reassemble the project” of the element and add the element to the form (in the main project):
Now let's check some methods of our element: public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
tableCustoms1.Rows.Add(new Row());
tableCustoms1.Rows.Add(new Row());
tableCustoms1.Rows[0].Cells[0].Value = "1";
tableCustoms1.Rows[1].Cells[1].Value = "2";
tableCustoms1.CountRow++;
tableCustoms1.Rows[0].Cells[0].Value = "";
}
}
We launch our project: