This question was closed a long time ago. I've tried to re-open it (and flagged it for moderator attention) but my flag was rejected. It seems clear to me that the two questions under consideration are:
Is there a built-in function to repeat a char in .net?
Is there a built-in function to repeat a string in .net?
The question was closed because the other question solves how to repeat a char. As there is no canonical (non-closed) question on how to repeat a string, I feel like this question should remain open (and/or perhaps modified to include only a discussion involving repeating strings).
Or, if there already exists an answer to the string portion of this question, perhaps this question should be modified to include duplicate references to both. (I could not find an ideal candidate, or I would have done so myself)