Grouping in a sorted asp:GridView - asp.net

Question

I need a grouping in a sorted asp:Gridview like the following picture shows:
Can someone give me a hint about how to proceed? Is it possible to group on RowBound somehow?

Answer 1

You can use the following algorithm to do your work:
/****************************************
* Grouping Algorithmus
* by Björn Karpenstein
* http://www.capri-soft.de/blog
****************************************/
// Nach dieser Spalte soll gruppiert werden
int k = 1;
// Für alle Zeilen (VON UNTEN NACH OBEN)
for (int i = GridView1.Rows.Count - 1; i > 0; i--)
{
GridViewRow row = GridView1.Rows[i];
GridViewRow previousRow = GridView1.Rows[i - 1];
// Für alle Spalten
for (int j = 0; j < row.Cells.Count; j++)
{
if ((row.Cells[k].Text == previousRow.Cells[k].Text) && (row.Cells[j].Text == previousRow.Cells[j].Text))
{
if (previousRow.Cells[j].RowSpan == 0)
{
if (row.Cells[j].RowSpan == 0)
{
previousRow.Cells[j].RowSpan += 2;
}
else
{
previousRow.Cells[j].RowSpan = row.Cells[j].RowSpan + 1;
}
row.Cells[j].Visible = false;
}
}
}
}

Answer 2

You can do this in the RowDataBound event. You have to remember that rowspan and the removal of the next cell has to be done backwards since the next row does not exist yet. row["myValue"] is the column containing the values that need to be compared.
string groupValue = string.Empty;
int rowSpanCount = 1;
//change this to the column index that needs spanning
int columnIndex = 6;
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
//check if the current row is a datarow
if (e.Row.RowType == DataControlRowType.DataRow)
{
//get the current row number
int currentRow = e.Row.DataItemIndex;
//cast the current row to a datarowview
DataRowView row = e.Row.DataItem as DataRowView;
//check if the groupValue equals the current row, if so +1 rowspan in needed
if (groupValue == row["myValue"].ToString())
{
rowSpanCount++;
}
else if (currentRow > 1 && rowSpanCount > 1)
{
//apply rowspan to the first cell
GridView1.Rows[currentRow - rowSpanCount].Cells[columnIndex].RowSpan = rowSpanCount;
//remove the spanned rows
for (int i = 1; i < rowSpanCount; i++)
{
GridView1.Rows[currentRow - (rowSpanCount - i)].Cells.RemoveAt(columnIndex);
}
//reset the rowSpanCount
rowSpanCount = 1;
}
//set the groupValue variable for value comparison in the next row
groupValue = row["myValue"].ToString();
}
}