In HTML in the td of a table you can break text by using
between the words. This also works in the HeaderText of a TemplateItem but not the HeaderTex
Set HtmlEncode = false
inside the BoundField
<asp:BoundField DataField="SomeDataField"
HeaderText="SomeHeader<br />(OtherData)"
HtmlEncode="false" />
BoundField.HtmlEncode
is true by default which means that if HTML is added in the text it will be encoded.
If HtmlEncode is set to false the text is not encoded and the br will work as expected. Unfortunately is not possible to specify this only for the header text, it will affect the cell contents as well.
For those of you trying to do this without disabling HtmlEncode it's pretty simple, if a little silly looking. Just use a real line break. Like so...
<asp:BoundField DataField="ProposedExtractionStartDate" HeaderText="Proposed
Extraction Start Date" SortExpression="ProposedExtractionStartDate" DataFormatString="{0:MM/dd/yyyy}" />
That will actually come out as multi-line when the HTML renders.
If there is a character combination that will signify this, I would love to know it.