在开发中尝试了使用Realm作为本地数据库，学习过程中算是一波三折。本次项目使用Swift 开发，过程还算顺畅。废话不说贴代码：
Realm其对代码侵入性很强，Realm要求类继承Object的基类。意味着不能再继承其他自定义的子类。在接入Realm之前整个项目已经基本成型，而主旨是在项目当中添加一个首页数据本地持久化的功能，因此拒绝改变原有模块；同时本着模块化的思想，尽量低耦合另起一个模块来实现此功能后期优点要多。
这是Model类（这里介绍两个界面共用一个Model的情况）
import SwiftyJSON
//这是 model
struct M_Attention {
var code = ""
var id = ""
var isDelete = false
var name = ""
var proposedPrice = "--"
var quoteChange = "--"
var winery = ""
var last_price = "--"
var isFollow = false
var isSelect = false
var ratio = ""
}
//遵循协议 SP_JsonModel 这在我的实战系列（网络层）中有提到
extension M_Attention:SP_JsonModel {
init(_ json: JSON) {
if json.isEmpty{
return
}
code = json["code"].stringValue
id = json["id"].stringValue
isDelete = json["is_delete"].boolValue
name = json["name"].stringValue
proposedPrice = String(format:"%.2f",json["proposed_price"].doubleValue)
proposedPrice = proposedPrice.isEmpty ? "--" : proposedPrice
quoteChange = json["quote_change"].stringValue
quoteChange = quoteChange.isEmpty ? "--" : quoteChange
winery = json["winery"].stringValue
isFollow = json["is_select"].boolValue
last_price = json["last_price"].stringValue
last_price = last_price.isEmpty ? "--" : last_price
ratio = json["ratio"].stringValue
isSelect = false
}
}
//另一个页面
struct M_Market {
var high_ratio = [M_Attention]()
var low_ratio = [M_Attention]()
}
extension M_Market:SP_JsonModel {
init(_ json: JSON) {
if json.isEmpty{
return
}
let high_ratioArr = json["high_ratio"].arrayValue
for item in high_ratioArr {
let value = M_Attention(item)
high_ratio.append(value)
}
let low_ratioArr = json["low_ratio"].arrayValue
for item in low_ratioArr {
let value = M_Attention(item)
low_ratio.append(value)
}
}
}
添加 Realm 功能
import RealmSwift
import Realm
/*
因为已经建立好了模型，
原则：不改变原有模型设计之上来添加功能，尽量将模块分离.
*/
//总表，这里涉及到不同页面共用同一个 M_Attention，因为使用的是默认表 Realm()，所以这样设计加以区分各页面数据。使用List实现一对多关系。
class M_AttentionRealmS: Object {
var id = ""
var attentions = List()
var high_ratio = List()
var low_ratio = List()
override static func primaryKey() -> String? {
return "id"
}
}
// M_AttentionRealm 对应 M_Attention
class M_AttentionRealm: Object {
dynamic var code = ""
dynamic var id = ""
dynamic var isDelete = false
dynamic var name = ""
dynamic var proposedPrice = "--"
dynamic var quoteChange = "--"
dynamic var winery = ""
dynamic var last_price = "--"
dynamic var isFollow = false//是否已加自选
dynamic var isSelect = false
dynamic var ratio = ""
override static func primaryKey() -> String? {
return "code"
}
func write(_ model:M_Attention) {
code = model.code
id = model.id
isDelete = model.isDelete
name = model.name
proposedPrice = model.proposedPrice
quoteChange = model.quoteChange
winery = model.winery
last_price = model.last_price
isFollow = model.isFollow
isSelect = model.isSelect
ratio = model.ratio
}
func read() -> M_Attention {
return M_Attention(code: code,
id: id,
isDelete: isDelete,
name: name,
proposedPrice: proposedPrice,
quoteChange: quoteChange,
winery: winery,
last_price: last_price,
isFollow: isFollow,
isSelect: isSelect,
ratio: ratio)
}
}
写入
fileprivate func t_获取自选列表() {
My_API.t_获取自选列表(page:_pageIndex).post(M_Attention.self) { [weak self](isOk, data, error) in
self?.sp_EndRefresh()
if isOk {
guard let datas = data as? [M_Attention] else{return}
if self?._pageIndex == 1 {
DispatchQueue.global().async {
do {
let realm = try Realm()
let m_AttentionRealmS = M_AttentionRealmS()
m_AttentionRealmS.id = "m_AttentionRealm"
for item in datas {
let m_AttentionRealm = M_AttentionRealm()
m_AttentionRealm.write(item)
m_AttentionRealmS.attentions.append(m_AttentionRealm)
}
try realm.write {
//写入，根据主键更新
realm.add(m_AttentionRealmS, update: true)
}
//打印出数据库地址
//print(realm.configuration.fileURL)
DispatchQueue.main.async { _ in}
} catch let err {
print(err)
}
}
}else{
}else{
}
}
}
另一个页面的数据
fileprivate func t_获取行情数据() {
My_API.t_获取行情数据.post(M_Market.self) { [weak self](isOk, data, error) in
self?.sp_EndRefresh()
if isOk {
guard let datas = data as? M_Market else{return}
DispatchQueue.global().async {
do {
let realm = try Realm()
let m_MarketRealm = M_AttentionRealmS()
m_MarketRealm.id = "m_MarketRealm"
m_MarketRealm.high_ratio.removeAll()
m_MarketRealm.low_ratio.removeAll()
for item in datas.high_ratio {
let m_AttentionRealm = M_AttentionRealm()
m_AttentionRealm.write(item)
m_MarketRealm.high_ratio.append(m_AttentionRealm)
}
for item in datas.low_ratio {
let m_AttentionRealm = M_AttentionRealm()
m_AttentionRealm.write(item)
m_MarketRealm.low_ratio.append(m_AttentionRealm)
}
try realm.write {
//写入，根据主键更新
realm.add(m_MarketRealm, update: true)
}
//打印出数据库地址
//print(realm.configuration.fileURL)
DispatchQueue.main.async { _ in
}
} catch let err {
print(err)
}
}
}else{}
}
}
读取
fileprivate var _datas = [M_Attention]()
fileprivate func makeUI() {
lab_range_W.constant = sp_fitSize((95,110,125))
do {
let realm = try Realm()
if let theRealms:M_AttentionRealmS = realm.object(ofType: M_AttentionRealmS.self, forPrimaryKey: "m_AttentionRealm") {
for item in theRealms.attentions {
_datas.append(item.read())
}
}
} catch let err {
print(err)
}
makeTableView()
}
另一个页面的数据
var _datas = M_Market()
fileprivate func makeUI() {
do {
let realm = try Realm()
if let theRealms:M_AttentionRealmS = realm.object(ofType: M_AttentionRealmS.self, forPrimaryKey: "m_MarketRealm") {
for item in theRealms.high_ratio {
self._datas.high_ratio.append(item.read())
}
for item in theRealms.low_ratio {
self._datas.low_ratio.append(item.read())
}
}
} catch let err {
print(err)
}
}
附：新闻资讯页面
import SwiftyJSON
import RealmSwift
import Realm
//不存在多页面 共享 M_News
class M_NewsRealm: Object {
// 自建 index ，目的：只保存最新第一页的数据
dynamic var index = 0
dynamic var article = ""
dynamic var href = ""
dynamic var title = ""
dynamic var text = ""
dynamic var news_time = ""
dynamic var thumb_img = ""
dynamic var author = ""
dynamic var origin = ""
override static func primaryKey() -> String? {
return "index"
}
func write(_ model:M_News, _ index:Int) {
index = index
article = model.article
href = model.href
title = model.title
text = model.text
news_time = model.news_time
thumb_img = model.thumb_img
author = model.author
origin = model.origin
}
func read() -> M_News {
return M_News(article: article,
href: href,
title: title,
text: text,
news_time: news_time,
thumb_img: thumb_img,
author: author,
origin: origin)
}
}
struct M_News {
var article = ""
var href = ""
var title = ""
var text = ""
var news_time = ""
var thumb_img = ""
var author = ""
var origin = ""
var newsYY:String {
let arr = news_time.components(separatedBy: " ")
return arr.count > 0 ? arr.first! : "--"
}
var newsMM:String {
let arr = news_time.components(separatedBy: " ")
return arr.count > 0 ? arr.last! : "--"
}
}
extension M_News:SP_JsonModel {
init(_ json: JSON) {
if json.isEmpty{
return
}
author = json["author"].stringValue
origin = json["origin"].stringValue
article = json["article"].stringValue
href = json["href"].stringValue
title = json["title"].stringValue
text = json["text"].stringValue
news_time = json["news_time"].stringValue
thumb_img = json["thumb_img"].stringValue
}
}
//写入
DispatchQueue.global().async {
do {
let realm = try Realm()
for (index,item) in datas.enumerated() {
let m_AttentionRealm = M_NewsRealm()
m_AttentionRealm.write(item, index)
try realm.write {
//写入，根据主键更新
realm.add(m_AttentionRealm, update: true)
}
}
//打印出数据库地址
//print(realm.configuration.fileURL)
DispatchQueue.main.async { _ in }
} catch let err {
print(err)
}
}
//读取
do {
let realm = try Realm()
let theRealms:Results = realm.objects(M_NewsRealm.self)
for item in theRealms {
_datas.append(item.read())
}
} catch let err {
print(err)
}