给一个NSDictionary按key排序
比如 key是 1,2,3,4,5 之类的
NSArray*sortedKeys=[[dict allKeys]sortedArrayUsingSelector:@selector(compare:)];
NSMutableArray*sortedValues=[NSMutableArray array];
for(NSString*keyin sortedKeys)
[sortedValuesaddObject:[dictobjectForKey:key]];