NSDictionary dictionaryWithObjectsAndKeys
NSDictionary *parmDic = [NSDictionary dictionaryWithObjectsAndKeys:self.objClass.appId,@"appId", self.objClass.cityCd,@"cityCd", self.objClass.channelID,@"channelId", 1,@"currentPage", 1,@"pageSize",nil]; NSDictionary *parmDic = [NSDictionary dictionaryWithObjectsAndKeys:@"SZ100",@"appId", @"苏州",@"cityCd",@"123",@"modelCd", 1,@"channelId", 1,@"currentPage", 1,@"pageSize",nil];
网络传参，走到这一步就挂了，报
于是改成下面那样也不行，继续查，才知道是
dictionaryWithObjectsAndKeys方法在遇到nil对象时，会以为是最终的结束标志。
见，
http://www.cocoachina.com/bbs/read.php?tid-124307.html
最后就改成这样，才通过：
NSMutableDictionary* parmDic = [NSMutableDictionary dictionary];
[parmDic setValue:self.objClass.appId forKey:@"appId"];
[parmDic setValue:self.objClass.cityCd forKey:@"cityCd"];
[parmDic setValue:self.objClass.modelCd forKey:@"modelCd"];
[parmDic setValue:self.objClass.channelID forKey:@"channelID"];
[parmDic setValue:@(self.page) forKey:@"currentPage"];
[parmDic setValue:@(self.pageSize) forKey:@"pageSize"];
原文：http://www.cnblogs.com/developer-qin/p/4792696.html