In this article I will explain how to Rotate / Flip / Transpose DataTable - Convert DataTable Columns to Rows and Rows to Columns using C# and VB.Net.
This article also explains how to get back the original DataTable from the Rotated / Flipped / Transposed DataTable using C# and VB.Net.
I am making use of a GridView control to display the
Rotated / Flipped / Transposed DataTable.
HTML Markup
Below is the HTML Markup where I have
an ASP.Net GridView Control and two buttons one to Rotate / Flip / Transpose
DataTable Columns to Rows and another to Rotate / Flip / Transpose DataTable rows to Columns
<asp:GridView ID="GridView1" CssClass="Grid" HeaderStyle-CssClass="header" runat="server"
AutoGenerateColumns="true">
</asp:GridView>
<br />
<asp:Button ID="btnConvert1" runat="server" Text="Convert Rows to Columns" OnClick="Convert"
CommandArgument="1" />
<asp:Button ID="btnConvert2" runat="server" Text="Convert Columns to Rows" OnClick="Convert"
CommandArgument="2" Visible="false" />
Namespaces
You will need to import the following namespaces
C#
VB.Net
Binding the ASP.Net GridView Control
Below is the code to bind the ASP.Net GridView. You will notice that I am saving the DataTable to ViewState variable so that it can be reused later on.
The BindGrid method accepts an additional parameter rotate based on which I hide and show the GridView headers.
C#
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
DataTable dt = new DataTable();
dt.Columns.AddRange(new DataColumn[3] { new DataColumn("Item"), new DataColumn("Quantity"), new DataColumn("Price") });
dt.Rows.Add("Shirt", 145, 500);
dt.Rows.Add("Jeans", 0, 2000);
dt.Rows.Add("Trousers", 190, 1545);
dt.Rows.Add("Tie", 30, 200);
dt.Rows.Add("Cap", 0, 300);
dt.Rows.Add("Hat", 90, 350);
dt.Rows.Add("Scarf", 290, 140);
dt.Rows.Add("Belt", 150, 400);
ViewState["dt"] = dt;
BindGrid(dt, false);
}
}
private void BindGrid(DataTable dt, bool rotate)
{
GridView1.ShowHeader = !rotate;
GridView1.DataSource = dt;
GridView1.DataBind();
if (rotate)
{
foreach (GridViewRow row in GridView1.Rows)
{
row.Cells[0].CssClass = "header";
}
}
}
VB.Net
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
If Not IsPostBack Then
Dim dt As New DataTable()
dt.Columns.AddRange(New DataColumn(2) {New DataColumn("Item"), New DataColumn("Quantity"), New DataColumn("Price")})
dt.Rows.Add("Shirt", 145, 500)
dt.Rows.Add("Jeans", 0, 2000)
dt.Rows.Add("Trousers", 190, 1545)
dt.Rows.Add("Tie", 30, 200)
dt.Rows.Add("Cap", 0, 300)
dt.Rows.Add("Hat", 90, 350)
dt.Rows.Add("Scarf", 290, 140)
dt.Rows.Add("Belt", 150, 400)
ViewState("dt") = dt
BindGrid(dt, False)
End If
End Sub
Private Sub BindGrid(dt As DataTable, rotate As Boolean)
GridView1.ShowHeader = Not rotate
GridView1.DataSource = dt
GridView1.DataBind()
If rotate Then
For Each row As GridViewRow In GridView1.Rows
row.Cells(0).CssClass = "header"
Next
End If
End Sub
Rotate / Flip / Transpose
DataTable Columns to Rows and Rows to Columns using C# and VB.Net
In the below code I am making use of two DataTables, one the original one from ViewState variable and other one I would use to store the rotated / flipped / transposed rows.
Then finally the rotated / flipped / transposed DataTable is bound to the ASP.Net GridView Control
C#
protected void Convert(object sender, EventArgs e)
{
DataTable dt = (DataTable)ViewState["dt"];
if ((sender as Button).CommandArgument == "1")
{
btnConvert1.Visible = false;
btnConvert2.Visible = true;
DataTable dt2 = new DataTable();
for (int i = 0; i <= dt.Rows.Count; i++)
{
dt2.Columns.Add();
}
for (int i = 0; i < dt.Columns.Count; i++)
{
dt2.Rows.Add();
dt2.Rows[i][0] = dt.Columns[i].ColumnName;
}
for (int i = 0; i < dt.Columns.Count; i++)
{
for (int j = 0; j < dt.Rows.Count; j++)
{
dt2.Rows[i][j + 1] = dt.Rows[j][i];
}
}
BindGrid(dt2, true);
}
else
{
btnConvert1.Visible = true;
btnConvert2.Visible = false;
BindGrid(dt, false);
}
}
VB.Net
Protected Sub Convert(sender As Object, e As EventArgs)
Dim dt As DataTable = DirectCast(ViewState("dt"), DataTable)
If TryCast(sender, Button).CommandArgument = "1" Then
btnConvert1.Visible = False
btnConvert2.Visible = True
Dim dt2 As New DataTable()
For i As Integer = 0 To dt.Rows.Count
dt2.Columns.Add()
Next
For i As Integer = 0 To dt.Columns.Count - 1
dt2.Rows.Add()
dt2.Rows(i)(0) = dt.Columns(i).ColumnName
Next
For i As Integer = 0 To dt.Columns.Count - 1
For j As Integer = 0 To dt.Rows.Count - 1
dt2.Rows(i)(j + 1) = dt.Rows(j)(i)
Next
Next
BindGrid(dt2, True)
Else
btnConvert1.Visible = True
btnConvert2.Visible = False
BindGrid(dt, False)
End If
End Sub
Demo
Downloads
