问题
I have the following code:
string foo = "blah".PadLeft(4, ' ');
But when I check it, instead of foo being "____blah" (with 4 spaces at the start), it's just "blah". Why doesn't PadLeft do what I expect?
回答1:
Because the first argument is total length of resulting string and not number of character to pad. So in your example you want to use 8 instead of 4.
回答2:
The first argument to PadLeft specifies the total resulting length you want. Since "blah" starts out four characters long, no padding is added when you specify a length of four. If you want to insert four spaces, change your call to string foo = "blah".PadLft(8, ' '); Since the default padding character is a space, you can skip specifying that and just use string foo = "blah".PadLeft(8)
来源：https://stackoverflow.com/questions/3581416/why-is-padleft-not-working