场景：从上一个页面请求的数据，在上一个VC中能够改变数值，刷新界面；然后需要将数据传到下一个页面，并且在下一个页面也需要对值进行改变，刷新界面，并且还需要将最后的数据回传到上一个页面；
做这个时，第一时间想到了数据使用Class 而没有使用Struct ，因为Struct 的值没法改变，故 直接建立了Model
class ContractMakeBillDetailModel: HandyJSON {
required init() { }
var moneys : String! // ": "900.00"
var modify_money : String!
var cost_name : String! // ": "管理费",
var house_id : String! // ": "16455",
var memo : String!
var cost_type : String! // ": "1",
var cost_id : String! // ": "2",
var dis_id : String!
var nofirst : String!
var type : String!
var id : String!
// 是否选中
var isSelected = true
}
class ContractMakeBillModel: HandyJSON {
required init() { }
var bill_type :String! // ": 5,
var begin_date :String! // ": "2019-06-05",
var bill_month :String! // ": "201906",
var end_date :String! // ": "2020-06-04",
var splitmoney :String! // ": 1,
/// 1 - 押金 ,3 - 零散期 ,5 - 月账单
var number :String! // ": 1,
var moneys :[ContractMakeBillDetailModel]! // ":
// 是否选中
var isSelected = true
}
然后直接在页面跳转时，将数据传到下个页面，但是，数据在下一个页面被改变时，上一个页面的数据也被改变了。原来Class是指针引用，后面虽然用其他数据去接收了这个数据，但是其指针仍然指向原地址
(lldb) p preModel
([&.ContractMakeBillModel) $R0 = 0x0000000280b34680 {
moneys = 2 values {
[0] = 0x0000000281e7dad0 {
moneys = "5.00"
modify_money = "5.00"
cost_name = some {
_guts = {
_object = (_countAndFlagsBits = 2, _object = 0x50000002825a4460)
}
}
}
[1] = 0x0000000281e44000 {
moneys = "89.00"
modify_money = "89.00"
cost_name = some {
_guts = {
_object = (_countAndFlagsBits = 3, _object = 0x50000002825a4480)
}
}
}
}
isSelected = true
}
(lldb) p previewData
([&.ContractMakeBillModel]) $R2 = 1 value {
moneys = 2 values {
[0] = 0x0000000281e7dad0 {
moneys = "5.00"
modify_money = "5.00"
cost_name = some {
_guts = {
_object = (_countAndFlagsBits = 2, _object = 0x50000002825a4460)
}
}
}
[1] = 0x0000000281e44000 {
moneys = "89.00"
modify_money = "89.00"
cost_name = some {
_guts = {
_object = (_countAndFlagsBits = 3, _object = 0x50000002825a4480)
}
}
}
}
isSelected = true
}
}
此时发现 两个moneys 地址是一样的，阿西；那此时，肯定要想到复制啊，于是 遵协议，实现方法
extension ContractMakeBillDetailModel : NSCopying,NSMutableCopying {
/*
使用NSCoping ，NSMutableCopying 会造成前后数据同时变化
*/
// NSCopying
func copy(with zone: NSZone? = nil) -> Any {
let model = ContractMakeBillDetailModel()
model.moneys = self.moneys
model.modify_money = self.modify_money
model.cost_name = self.cost_name
model.house_id = self.house_id
model.memo = self.memo
model.cost_type = self.cost_type
model.cost_id = self.cost_id
model.dis_id = self.dis_id
model.nofirst = self.nofirst
model.type = self.type
model.id = self.id
model.isSelected = self.isSelected
return model
}
// NSMutableCopying
func mutableCopy(with zone: NSZone? = nil) -> Any {
let model = ContractMakeBillDetailModel()
model.moneys = self.moneys
model.modify_money = self.modify_money
model.cost_name = self.cost_name
model.house_id = self.house_id
model.memo = self.memo
model.cost_type = self.cost_type
model.cost_id = self.cost_id
model.dis_id = self.dis_id
model.nofirst = self.nofirst
model.type = self.type
model.id = self.id
model.isSelected = self.isSelected
return model
}
}
extension ContractMakeBillModel: NSCopying,NSMutableCopying
{
func copy(with zone: NSZone? = nil) -> Any {
let model = ContractMakeBillModel()
model.bill_type = self.bill_type
model.begin_date = self.begin_date
model.bill_month = self.bill_month
model.end_date = self.end_date
model.splitmoney = self.splitmoney
model.number = self.number
var arr = [ContractMakeBillDetailModel]()
self.moneys.forEach { (subModel) in
arr.append(subModel.mutableCopy() as! ContractMakeBillDetailModel)
}
model.moneys = arr
model.isSelected = self.isSelected
return model
}
func mutableCopy(with zone: NSZone? = nil) -> Any {
let model = ContractMakeBillModel()
model.bill_type = self.bill_type
model.begin_date = self.begin_date
model.bill_month = self.bill_month
model.end_date = self.end_date
model.splitmoney = self.splitmoney
model.number = self.number
var arr = [ContractMakeBillDetailModel]()
self.moneys.forEach { (subModel) in
arr.append(subModel.mutableCopy() as! ContractMakeBillDetailModel)
}
model.moneys = arr
model.isSelected = self.isSelected
return model
}
}
注意，因为moneys 是一个数组，如果直接 model.moneys = self.moneys，那么他们内存地址又是同一个数值，改变一处，所有都会改变，所以需要用循环 单独拷贝；
点点滴滴，踏坑走起
发现一篇文章：可以走走看 Qio一哈
他们说使用Map 函数更牛逼
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