Widget如何共享Core Data?
How to share Core Data with Widget?
我想与 Widget 共享 Core Data。我想我需要创建 App Group(我知道该怎么做)。
但是我该如何与 Widget 共享 Core Data 数据库呢?
如果我想在我的应用程序中使用核心数据,我总是简单地创建一个新的 Xcode 项目并选中“使用核心数据”,然后我得到这段代码(Persistence.swift
- 下面) , 它将我连接到数据库。
如何修改它,以便与 Widget 共享此 Core Data 数据库?
Persistence.swift
import CoreData
struct PersistenceController {
static let shared = PersistenceController()
static var preview: PersistenceController = {
let result = PersistenceController(inMemory: true)
let viewContext = result.container.viewContext
for _ in 0..<10 {
let newItem = Item(context: viewContext)
newItem.timestamp = Date()
}
do {
try viewContext.save()
} catch {
// Replace this implementation with code to handle the error appropriately.
// fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
let nsError = error as NSError
fatalError("Unresolved error \(nsError), \(nsError.userInfo)")
}
return result
}()
let container: NSPersistentContainer
init(inMemory: Bool = false) {
container = NSPersistentContainer(name: "MyAppName")
if inMemory {
container.persistentStoreDescriptions.first!.url = URL(fileURLWithPath: "/dev/null")
}
container.loadPersistentStores(completionHandler: { (storeDescription, error) in
if let error = error as NSError? {
// Replace this implementation with code to handle the error appropriately.
// fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
/*
Typical reasons for an error here include:
* The parent directory does not exist, cannot be created, or disallows writing.
* The persistent store is not accessible, due to permissions or data protection when the device is locked.
* The device is out of space.
* The store could not be migrated to the current model version.
Check the error message to determine what the actual problem was.
*/
fatalError("Unresolved error \(error), \(error.userInfo)")
}
})
container.viewContext.automaticallyMergesChangesFromParent = true
}
}
在PersistenceController
class先加一个属性得到App GroupURL
var containerURL: URL {
return FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "group.com.myappname")!
}
然后在持久容器的商店描述中设置URL
init(inMemory: Bool = false) {
container = NSPersistentContainer(name: "MyAppName")
if inMemory {
container.persistentStoreDescriptions.first!.url = URL(fileURLWithPath: "/dev/null")
} else {
let storeURL = containerURL.appendingPathComponent("MyAppName.sqlite")
container.persistentStoreDescriptions.first!.url = storeURL
}
container.loadPersistentStores(completionHandler: { (storeDescription, error) in ...
用您的实际数据替换字符串文字。
我想与 Widget 共享 Core Data。我想我需要创建 App Group(我知道该怎么做)。 但是我该如何与 Widget 共享 Core Data 数据库呢?
如果我想在我的应用程序中使用核心数据,我总是简单地创建一个新的 Xcode 项目并选中“使用核心数据”,然后我得到这段代码(Persistence.swift
- 下面) , 它将我连接到数据库。
如何修改它,以便与 Widget 共享此 Core Data 数据库?
Persistence.swift
import CoreData
struct PersistenceController {
static let shared = PersistenceController()
static var preview: PersistenceController = {
let result = PersistenceController(inMemory: true)
let viewContext = result.container.viewContext
for _ in 0..<10 {
let newItem = Item(context: viewContext)
newItem.timestamp = Date()
}
do {
try viewContext.save()
} catch {
// Replace this implementation with code to handle the error appropriately.
// fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
let nsError = error as NSError
fatalError("Unresolved error \(nsError), \(nsError.userInfo)")
}
return result
}()
let container: NSPersistentContainer
init(inMemory: Bool = false) {
container = NSPersistentContainer(name: "MyAppName")
if inMemory {
container.persistentStoreDescriptions.first!.url = URL(fileURLWithPath: "/dev/null")
}
container.loadPersistentStores(completionHandler: { (storeDescription, error) in
if let error = error as NSError? {
// Replace this implementation with code to handle the error appropriately.
// fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
/*
Typical reasons for an error here include:
* The parent directory does not exist, cannot be created, or disallows writing.
* The persistent store is not accessible, due to permissions or data protection when the device is locked.
* The device is out of space.
* The store could not be migrated to the current model version.
Check the error message to determine what the actual problem was.
*/
fatalError("Unresolved error \(error), \(error.userInfo)")
}
})
container.viewContext.automaticallyMergesChangesFromParent = true
}
}
在PersistenceController
class先加一个属性得到App GroupURL
var containerURL: URL {
return FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "group.com.myappname")!
}
然后在持久容器的商店描述中设置URL
init(inMemory: Bool = false) {
container = NSPersistentContainer(name: "MyAppName")
if inMemory {
container.persistentStoreDescriptions.first!.url = URL(fileURLWithPath: "/dev/null")
} else {
let storeURL = containerURL.appendingPathComponent("MyAppName.sqlite")
container.persistentStoreDescriptions.first!.url = storeURL
}
container.loadPersistentStores(completionHandler: { (storeDescription, error) in ...
用您的实际数据替换字符串文字。