Prevent HTML encoding in auto-generated GridView columns - asp.net

Question

I have a GridView bound to a DataTable that I construct. Most columns in the table contain the raw HTML for a hypelinklink, and I would like that HTML to render as a link in the browser, but the GridView is automatically encoding the HTML, so it renders as markup.
How can I avoid this without explicitly adding HyperLink, or any other, columns?

Answer 1

Simply set the BoundColumn.HtmlEncode property to false:
<asp:BoundField DataField="HtmlLink" HtmlEncode="false" />
I am afraid that there is no easy way to disable HTML encoding of the contents in a GridView with AutoGenerateColumns= true. However, I can think of two workarounds that might solve the problem you are facing:
Option 1: Inherit the GridView class, override the Render method, loop through all cells, decode their contents, before executing the base method:
for (int i = 0; i < Rows.Count; i++)
{
for (int j = 0; j < Rows[i].Cells.Count; j++)
{
string encoded = Rows[i].Cells[j].Text;
Rows[i].Cells[j].Text = Context.Server.HtmlDecode(encoded);
}
}
Option 2: In a class inheriting from GridView or in the Page or Control using it, make your own inspection of the DataTable and create an explicit BoundColumn for each column:
foreach (DataColumn column in dataTable.Columns)
{
GridViewColumn boundColumn = new BoundColumn
{
DataSource = column.ColumnName,
HeaderText = column.ColumnName,
HtmlEncode = false
};
gridView.Columns.Add(boundColumn);
}

Answer 2

I was able to achieve this by using the solution that Jørn Schou-Rode provided, I modified a little bit to make it work from the RowDataBound Event of my Gridview.
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
for (int j = 0; j < e.Row.Cells.Count; j++)
{
string encoded = e.Row.Cells[j].Text;
e.Row.Cells[j].Text = Context.Server.HtmlDecode(encoded);
}
}
}

Answer 3

Another way is to add something like the following to the RowDataBound event handler...
If e.Row.RowType = DataControlRowType.Header Then
For Each col As TableCell In e.Row.Cells
Dim encoded As String = col.Text
col.Text = Context.Server.HtmlDecode(encoded)
Next
End If

Answer 4

Use OnRowCreated
protected void gvFm_RowCreated(object sender, GridViewRowEventArgs e)
{
foreach (TableCell cell in e.Row.Cells)
{
BoundField fldRef = (BoundField)((DataControlFieldCell)cell).ContainingField;
switch (fldRef.DataField)
{
case "ColToHide":
fldRef.Visible = false;
break;
case "ColWithoutEncode":
fldRef.HtmlEncode = false;
break;
}
}
}

Answer 5

Well since the html for the link is in your db already, you could just output the html to a literal control.
<asp:TemplateField HeaderText="myLink" SortExpression="myLink">
<ItemTemplate>
<asp:Literal ID="litHyperLink" runat="server" Text='<%# Bind("myLink", "{0}") %>' />
</ItemTemplate>
</asp:TemplateField>
This should render your link as raw text allowing the browser to render it as the link you expect it to be.

Answer 6

Since all the answers seem to be in C# and the questions was not specific, I ran into this issue using ASP.Net and VB.Net and the accepted solution did not work for me in VB (though I imagine it does work in C#). Hopefully this helps anyone working with VB.Net in ASP who stumbles upon this as I have.
In VB.Net BoundColumn cannot be added to Gridview.Columns as it is not a System.Web.UI.WebControls.DataControlField so instead one must use a BoundField which is a DataControlField.
BoundColoumn also does not have an HtmlEncode property however BoundField does. Also, in VB.Net DataSource becomes DataField.
For Each dataCol As DataColumn In dv.Table.Columns
Dim boundCol As New BoundField With {
.DataField = dataCol.ColumnName,
.HeaderText = dataCol.ColumnName,
.HtmlEncode = False
}
gvResult.Columns.Add(boundCol)
Next
gvResult.DataSource = dv
gvResult.Databind()
Also note that you must explicitly set AutoGenerateColumns="False" or the GridView will still generate columns along with the columns added above.

Answer 7

You can use this code in RowDataBound event if you want to disable HTML encoding in all rows and columns.
protected void GV_Product_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
foreach (TableCell ObjTC in e.Row.Cells)
{
string decodedText = HttpUtility.HtmlDecode(ObjTC.Text);
ObjTC.Text = decodedText;
}
}
}