如何将NSNumber转换为NSData？

Question

我需要通过GameKit传输一个整数,sendDataToAllPeers:withDataMode:error:但我不知道如何将我的NSNumber转换为NSData以便发送.我目前有:

NSNumber *indexNum = [NSNumber numberWithInt:index];
[gkSession sendDataToAllPeers:indexNum withDataMode:GKSendDataReliable error:nil];

但很明显,在我发送之前,indexNum需要转换为NSData.有人知道怎么做吗？

谢谢!

Answer 1

我不推荐NSKeyedArchiver这么简单的任务,因为它在它和类版本控制之上增加了PLIST开销.

包:

NSUInteger index = <some number>;
NSData *payload = [NSData dataWithBytes:&index length:sizeof(index)];

发送:

[session sendDataToAllPeers:payload withDataMode:GKSendDataReliable error:nil];

解包(在GKSession接收处理程序中):

NSUInteger index;
[payload getBytes:&index length:sizeof(index)];

迅速

var i = 123
let data = NSData(bytes: &i, length: sizeof(i.dynamicType))

var i2 = 0
data.getBytes(&i2, length: sizeof(i2.dynamicType))

print(i2) // "123"

Answer 2

存储它:

NSData *numberAsData = [NSKeyedArchiver archivedDataWithRootObject:indexNum];

要将其转换回NSNumber:

NSNumber *indexNum = [NSKeyedUnarchiver unarchiveObjectWithData:numberAsData];