字典数组，按照字典的match_num字段排序

NSArray *arr = responseObject[@"data"];
NSSortDescriptor *classWithSort=[[NSSortDescriptor alloc]initWithKey:@"match_num" ascending:YES];
NSArray *elementarr=[NSArray arrayWithObjects:classWithSort, nil];   
NSArray *data=[arr sortedArrayUsingDescriptors:elementarr];