DataGridView合并单元格

private void dgvRules_CellPainting(object sender, DataGridViewCellPaintingEventArgs e)
{
List<int> columnIndexList = new List<int>() { colRuleTestName.Index, colRuleCode.Index };
MergeCellInOneColumn(dgvRules, columnIndexList, e);
}

/// <summary>
/// DataGridView合并单元格
/// </summary>
/// <param name="e"></param>
/// <param name="dgv"></param>
private void MergeCellInOneColumn(DataGridView dgv, List<int> columnIndexList,DataGridViewCellPaintingEventArgs e)
{
if (e.CellStyle.Alignment == DataGridViewContentAlignment.NotSet)
{
e.CellStyle.Alignment = DataGridViewContentAlignment.MiddleCenter;
}
Brush gridBrush = new SolidBrush(dgv.GridColor);
SolidBrush backBrush = new SolidBrush(e.CellStyle.BackColor);
SolidBrush fontBrush = new SolidBrush(e.CellStyle.ForeColor);
int cellwidth;
//上面相同的行数
int upRows = 0;
//下面相同的行数
int downRows = 0;
//总行数
int count = 0;
if (columnIndexList.Contains(e.ColumnIndex) && e.RowIndex != -1)
{
cellwidth = e.CellBounds.Width;
Pen gridLinePen = new Pen(gridBrush);
string curValue = e.Value == null ? "" : e.Value.ToString().Trim();
if (!string.IsNullOrEmpty(curValue))
{
#region 获取下面的行数
for (int i = e.RowIndex; i < dgv.Rows.Count; i++)
{
if (dgv.Rows[i].Cells[e.ColumnIndex].Value.ToString().Equals(curValue))
{
downRows++;
if (e.RowIndex != i)
{
cellwidth = cellwidth < dgv.Rows[i].Cells[e.ColumnIndex].Size.Width ? cellwidth : dgv.Rows[i].Cells[e.ColumnIndex].Size.Width;
}
}
else
{
break;
}
}
#endregion
#region 获取上面的行数
for (int i = e.RowIndex; i >= 0; i--)
{
if (dgv.Rows[i].Cells[e.ColumnIndex].Value.ToString().Equals(curValue))
{
upRows++;
if (e.RowIndex != i)
{
cellwidth = cellwidth < dgv.Rows[i].Cells[e.ColumnIndex].Size.Width ? cellwidth : dgv.Rows[i].Cells[e.ColumnIndex].Size.Width;
}
}
else
{
break;
}
}
#endregion
count = downRows + upRows - 1;
if (count < 2)
{
return;
}
}
if (dgv.Rows[e.RowIndex].Selected)
{
backBrush.Color = e.CellStyle.SelectionBackColor;
fontBrush.Color = e.CellStyle.SelectionForeColor;
}
//以背景色填充
e.Graphics.FillRectangle(backBrush, e.CellBounds);
//画字符串
PaintingFont(e, cellwidth, upRows, downRows, count);
if (downRows == 1)
{
e.Graphics.DrawLine(gridLinePen, e.CellBounds.Left, e.CellBounds.Bottom - 1, e.CellBounds.Right - 1, e.CellBounds.Bottom - 1);
count = 0;
}
// 画右边线
e.Graphics.DrawLine(gridLinePen, e.CellBounds.Right - 1, e.CellBounds.Top, e.CellBounds.Right - 1, e.CellBounds.Bottom);

e.Handled = true;
}
}
/// <summary>
/// 画字符串
/// </summary>
/// <param name="e"></param>
/// <param name="cellwidth"></param>
/// <param name="UpRows"></param>
/// <param name="DownRows"></param>
/// <param name="count"></param>
private void PaintingFont(System.Windows.Forms.DataGridViewCellPaintingEventArgs e, int cellwidth, int upRows, int downRows, int count)
{
SolidBrush fontBrush = new SolidBrush(e.CellStyle.ForeColor);
int fontheight = (int)e.Graphics.MeasureString(e.Value.ToString(), e.CellStyle.Font).Height;
int fontwidth = (int)e.Graphics.MeasureString(e.Value.ToString(), e.CellStyle.Font).Width;
int cellheight = e.CellBounds.Height;

if (e.CellStyle.Alignment == DataGridViewContentAlignment.BottomCenter)
{
e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X + (cellwidth - fontwidth) / 2, e.CellBounds.Y + cellheight * downRows - fontheight);
}
else if (e.CellStyle.Alignment == DataGridViewContentAlignment.BottomLeft)
{
e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X, e.CellBounds.Y + cellheight * downRows - fontheight);
}
else if (e.CellStyle.Alignment == DataGridViewContentAlignment.BottomRight)
{
e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X + cellwidth - fontwidth, e.CellBounds.Y + cellheight * downRows - fontheight);
}
else if (e.CellStyle.Alignment == DataGridViewContentAlignment.MiddleCenter)
{
e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X + (cellwidth - fontwidth) / 2, e.CellBounds.Y - cellheight * (upRows - 1) + (cellheight * count - fontheight) / 2);
}
else if (e.CellStyle.Alignment == DataGridViewContentAlignment.MiddleLeft)
{
e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X, e.CellBounds.Y - cellheight * (upRows - 1) + (cellheight * count - fontheight) / 2);
}
else if (e.CellStyle.Alignment == DataGridViewContentAlignment.MiddleRight)
{
e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X + cellwidth - fontwidth, e.CellBounds.Y - cellheight * (upRows - 1) + (cellheight * count - fontheight) / 2);
}
else if (e.CellStyle.Alignment == DataGridViewContentAlignment.TopCenter)
{
e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X + (cellwidth - fontwidth) / 2, e.CellBounds.Y - cellheight * (upRows - 1));
}
else if (e.CellStyle.Alignment == DataGridViewContentAlignment.TopLeft)
{
e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X, e.CellBounds.Y - cellheight * (upRows - 1));
}
else if (e.CellStyle.Alignment == DataGridViewContentAlignment.TopRight)
{
e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X + cellwidth - fontwidth, e.CellBounds.Y - cellheight * (upRows - 1));
}
else
{
e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X + (cellwidth - fontwidth) / 2, e.CellBounds.Y - cellheight * (upRows - 1) + (cellheight * count - fontheight) / 2);
}
}