First you have to set particular cell - WrapMode property should be true.
Then you can use Paint function for datagridview.
this function automatically increased row height whatever you typed in cell
This is one of sample paint function.
protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates cellState, object value, object formattedValue, string errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts)
{
try
{
int mergeindex = ColumnIndex - m_nLeftColumn;
int i;
int nWidth;
int nWidthLeft;
string strText;
Pen pen = new Pen(Brushes.Black);
graphics.FillRectangle(new SolidBrush(SystemColors.Control), cellBounds);
graphics.DrawLine(new Pen(new SolidBrush(SystemColors.ControlDark)), cellBounds.Left, cellBounds.Bottom - 1, cellBounds.Right, cellBounds.Bottom - 1);
if (ColumnIndex == m_nRightColumn)
graphics.DrawLine(new Pen(new SolidBrush(SystemColors.ControlDark)), cellBounds.Right - 1, cellBounds.Top, cellBounds.Right - 1, cellBounds.Bottom);
RectangleF rectDest = RectangleF.Empty;
StringFormat sf = new StringFormat();
sf.Alignment = StringAlignment.Center;
sf.LineAlignment = StringAlignment.Center;
sf.Trimming = StringTrimming.EllipsisCharacter;
nWidth = 0;
for (i = m_nLeftColumn; i <= m_nRightColumn; i++)
nWidth += this.OwningRow.Cells[i].Size.Width;
nWidthLeft = 0;
for (i = m_nLeftColumn; i < ColumnIndex; i++)
nWidthLeft += this.OwningRow.Cells[i].Size.Width;
strText = this.OwningRow.Cells[m_nLeftColumn].Value.ToString();
rectDest = new RectangleF(cellBounds.Left - nWidthLeft, cellBounds.Top, nWidth, cellBounds.Height);
graphics.DrawString(strText, new Font("Arial", 10, FontStyle.Regular), Brushes.Black, rectDest, sf);
}
catch (Exception ex)
{
Trace.WriteLine(ex.ToString());
}
}