Want to buy a short sale,but the house needs a roof in about a year or two. Can you still get homeowners insrance to buy it ,and say fix it with in the year.

You may not be able to get the proper home insurance. New roofs are very expensive and I'm not aware of any insurance company that would insure your home minus the roof. You could try, but I'm not confident of you finding anyone to insure this home.

Also, even if you did buy the home, do you have lots of money to fix the roof on your own even in a year? What are you planning on doing when it rains hard or heavy snow is on your roof? Use a tarp?

Most [reputable] companies will want to visually inspect the property before agreeing to bind coverage. If the roof is in such bad shape, you will have to do the repairs first. Plus, assuming you're not living in the house because of the bad roof then you also have the issue of the home being vacant. A house cannot be vacant for more than 60 days so you'd have to have the repairs done practically right away.