可变数组转data
NSData *arrdata = [NSKeyedArchiver archivedDataWithRootObject:weakSelf.arr];
data转可变数组
self.array = [NSKeyedUnarchiver unarchiveObjectWithData:data];
可变数组转data
NSData *arrdata = [NSKeyedArchiver archivedDataWithRootObject:weakSelf.arr];
data转可变数组
self.array = [NSKeyedUnarchiver unarchiveObjectWithData:data];