C＃时间格式怪异

Question

I have the following string TheTimeFormat as the custom time format:

  "{0:h:mm tt}"

I have the following DateTime TheTime:

  {1/14/2011 2:19:00 AM}

I have the following statement

  ThisTime = TheTime.ToString(TheTimeFormat);

Why is ThisTime equal to " {0:2:19 AM} " . It should be 2:19 AM and I'm not seeing why. Not that in a gridview, I use the following statement and it works like a charm:

((BoundField)(MyGrid.Columns[0])).DataFormatString = TheUserPreferences.UserTimeFormat ; where TheUserPreferences.UserTimeFormat is the same format string.

Any suggestions?

Answer 1

When you put a time format into DateTime 's ToString method, you don't need the placeholder; that is, you could have this:

TheTimeFormat = "h:mm tt";

and

ThisTime = TheTime.ToString(TheTimeFormat)

would give you the desired output.

EDIT:

Per the extended question in the comment, this would allow you to put your format in something that requires a placeholder (and store the aforementioned version of TheTimeFormat in the db):

string formatWithPlaceholder = "{0:" + TheTimeFormat + "}";

I just briefly played around with string.Format instead of concatentation, but having the braces in the format is giving issues. Nonetheless, this works, but I don't particularly like the concatenation.

Answer 2

Change TheTimeFormat to simply "0:h:mm tt" .

You only need the "{X:YYY}" format when you are using String.Format() or the other methods like Console.WriteLine() that use String.Format() internally.