//定义一个字符串

NSString *str =@"   HGGHSDgAs das  djahkadafqskj lxacna ma zb c A sGHFGHGH   ";

NSString *str1=[str stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];

运行结果：2015-10-01 16:30:59.977 16-测试[1072:34512] str=HGGHSDgAs das  djahkadafqskj lxacna ma zb c A sGHFGHGH

Program ended with exit code: 0

//定义一个字符串

NSString *str =@"   HGGHSDgAs das  djahkadafqskj lxacna ma zb c A sGHFGHGH   ";

NSString *str1=[str stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];

运行结果：2015-10-01 16:30:59.977 16-测试[1072:34512] str=HGGHSDgAs das  djahkadafqskj lxacna ma zb c A sGHFGHGH

Program ended with exit code: 0