Formatting GridView

To Format the values displayed in GridView:
For BOUNDCOLUMN, use the DataFormatString argument

For TEMPLATECOLUMN, use the second argument of Bind() to format data
Eg:

See complete list of formatting:
Source :http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.boundfield.dataformatstring.aspx

Format character	Description	Example
C or c	Displays numeric values in currency format. You can specify the number of decimal places.	Format: {0:C} 123.456 -> $123.46 Format: {0:C3} 123.456 -> $123.456
D or d	Displays integer values in decimal format. You can specify the number of digits. (Although the type is referred to as "decimal", the numbers are formatted as integers.)	Format: {0:D} 1234 -> 1234 Format: {0:D6} 1234 -> 001234
E or e	Displays numeric values in scientific (exponential) format. You can specify the number of decimal places.	Format: {0:E} 1052.0329112756 -> 1.052033E+003 Format: {0:E2} -1052.0329112756 -> -1.05e+003
F or f	Displays numeric values in fixed format. You can specify the number of decimal places.	Format: {0:F} 1234.567 -> 1234.57 Format: {0:F3} 1234.567 -> 1234.567
G or g	Displays numeric values in general format (the most compact of either fixed-point or scientific notation). You can specify the number of significant digits.	Format: {0:G} -123.456 -> -123.456 Format: {0:G2} -123.456 -> -120
N or n	Displays numeric values in number format (including group separators and optional negative sign). You can specify the number of decimal places.	Format: {0:N} 1234.567 -> 1,234.57 Format: {0:N4} 1234.567 -> 1,234.5670
P or p	Displays numeric values in percent format. You can specify the number of decimal places.	Format: {0:P} 1 -> 100.00% Format: {0:P1} .5 -> 50.0%
R or r	Displays Single, Double, or BigInteger values in round-trip format.	Format: {0:R} 123456789.12345678 -> 123456789.12345678
X or x	Displays integer values in hexadecimal format. You can specify the number of digits.	Format: {0:X} 255 -> FF Format: {0:x4} 255 -> 00ff

d	Short date pattern.	Format: {0:d} 6/15/2009 1:45:30 PM -> 6/15/2009
D	Long date pattern.	Format: {0:D} 6/15/2009 1:45:30 PM ->Monday, June 15, 2009
f	Full date/time pattern (short time).	Format: {0:f} 6/15/2009 1:45:30 PM -> Monday, June 15, 2009 1:45 PM
F	Full date/time pattern (long time).	Format: {0:F} 6/15/2009 1:45:30 PM -> Monday, June 15, 2009 1:45:30 PM
g	General date/time pattern (short time).	Format: {0:g} 6/15/2009 1:45:30 PM -> 6/15/2009 1:45 PM
G	General date/time pattern (long time).	Format: {0:G} 6/15/2009 1:45:30 PM -> 6/15/2009 1:45:30 PM
M or m	Month/day pattern.	Format: {0:M} 6/15/2009 1:45:30 PM -> June 15
O or o	Round-trip date/time pattern.	Format: {0:o} 6/15/2009 1:45:30 PM -> 2009-06-15T13:45:30.0900000
R or r	RFC1123 pattern (for information, see DateTimeFormatInfo.RFC1123Pattern).	Format: {0:R} 6/15/2009 1:45:30 PM -> Mon, 15 Jun 2009 20:45:30 GMT
s	Sortable date/time pattern.	Format: {0:s} 6/15/2009 1:45:30 PM -> 2009-06-15T13:45:30
t	Short time pattern.	Format: {0:t} 6/15/2009 1:45:30 PM -> 1:45 PM
T	Long time pattern.	Format: {0:T} 6/15/2009 1:45:30 PM -> 1:45:30 PM
u	Universal sortable date/time pattern.	Format: {0:u} 6/15/2009 1:45:30 PM -> 2009-06-15 20:45:30Z
U	Universal full date/time pattern.	Format: {0:U} 6/15/2009 1:45:30 PM -> Monday, June 15, 2009 8:45:30 PM
Y or y	Year month pattern.	Format: {0:Y} 6/15/2009 1:45:30 PM -> June, 2009