String formatting: negative/positive floating point numbers

How can I use String.Format in C# so doubles开发者_如何学Go are displayed like this:

example:

___-1.000

____1.000

__100.123

-1000.321

_1000.214

etc...

Where _ is space (" ");

All I can do is String.Format("{0:F3}", -123.321);

You can use alignment:

String.Format("{0,10:F3}", -123.321)

where 10 is preffered length.

See Composite Formatting.

Found a quick article, in short:

String.Format("{0,10:0.0}", 123.4567);    // "     123.5"
String.Format("{0,-10:0.0}", 123.4567);   // "123.5     "
String.Format("{0,10:0.0}", -123.4567);   // "    -123.5"
String.Format("{0,-10:0.0}", -123.4567);  // "-123.5    "

Source: Here <- Look here for more.