private void dataGridView1_CellPainting(object sender, DataGridViewCellPaintingEventArgs e)
{
Brush gridBrush = new SolidBrush(this.dataGridView1.GridColor);
SolidBrush backBrush = new SolidBrush(e.CellStyle.BackColor);
SolidBrush fontBrush = new SolidBrush(e.CellStyle.ForeColor);
int cellheight;
int fontheight;
int cellwidth;
int fontwidth;
int countU = 0;
int countD = 0;
int count = 0;
// 对第1列相同单元格进行合并
if (e.ColumnIndex == 0 && e.RowIndex != -1)
{
cellheight = e.CellBounds.Height;
fontheight = (int)e.Graphics.MeasureString(e.Value.ToString(), e.CellStyle.Font).Height;
cellwidth = e.CellBounds.Width;
fontwidth = (int)e.Graphics.MeasureString(e.Value.ToString(), e.CellStyle.Font).Width;
Pen gridLinePen = new Pen(gridBrush);
string curValue = e.Value == null ? "" : e.Value.ToString().Trim();
string curSelected = this.dataGridView1.Rows[e.RowIndex].Cells[0].Value == null ? ""
: this.dataGridView1.Rows[e.RowIndex].Cells[0].Value.ToString().Trim();
if (!string.IsNullOrEmpty(curValue))
{
for (int i = e.RowIndex; i < this.dataGridView1.Rows.Count; i++)
{
if (this.dataGridView1.Rows[i].Cells[0].Value.ToString().Equals(curValue))
{
this.dataGridView1.Rows[i].Cells[0].Selected = this.dataGridView1.Rows[e.RowIndex].Selected;
this.dataGridView1.Rows[i].Selected = this.dataGridView1.Rows[e.RowIndex].Selected;
countD++;
}
else
{
break;
}
}
for (int i = e.RowIndex; i >= 0; i--)
{
if (this.dataGridView1.Rows[i].Cells[0].Value.ToString().Equals(curValue))
{
this.dataGridView1.Rows[i].Cells[0].Selected = this.dataGridView1.Rows[e.RowIndex].Selected;
this.dataGridView1.Rows[i].Selected = this.dataGridView1.Rows[e.RowIndex].Selected;
countU++;
}
else
{
break;
}
}
count = countD + countU - 1;
if (count < 2) { return; }
}
if (this.dataGridView1.Rows[e.RowIndex].Selected)
{
backBrush.Color = e.CellStyle.SelectionBackColor;
fontBrush.Color = e.CellStyle.SelectionForeColor;
}
e.Graphics.FillRectangle(backBrush, e.CellBounds);
e.Graphics.DrawString((String)e.Value, e.CellStyle.Font, fontBrush, e.CellBounds.X + (cellwidth - fontwidth) / 2, e.CellBounds.Y - cellheight * (countU - 1) + (cellheight * count - fontheight) / 2);
if (countD == 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;
}
}