Swift核心數據預加載persistentStoreCoordinator：

Question

什麼需要修改來預加載我的sqlite文件？我將該文件添加到項目中，這讓我認爲我必須對此代碼進行更改。

lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator? = { 
    // The persistent store coordinator for the application. This implementation creates and return a coordinator, having added the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail. 
    // Create the coordinator and store 
    var coordinator: NSPersistentStoreCoordinator? = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel) 
    let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("junkapp.sqlite") 
    var error: NSError? = nil 
    var failureReason = "There was an error creating or loading the application's saved data." 
    if coordinator!.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil, error: &error) == nil { 
     coordinator = nil 
     // Report any error we got. 
     let dict = NSMutableDictionary() 
     dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data" 
     dict[NSLocalizedFailureReasonErrorKey] = failureReason 
     dict[NSUnderlyingErrorKey] = error 
     //error = NSError.errorWithDomain("YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict) 
     // Replace this with code to handle the error appropriately. 
     // abort() 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. 
     NSLog("Unresolved error \(error), \(error!.userInfo)") 
     abort() 
    } 

    return coordinator 
}() 

Answer 1

只需將文件url更改爲指向您的SQLite文件。

您從包到文檔目錄需要

1. 副本SQLite的文件。
2. 參考文件網址addPersistentStore...。

例如

// Copying 
let path = NSBundle.mainBundle().pathForResource("sqlitefile", ofType:"sqlite")! 
let destinationPath = 
    self.applicationDocumentsDirectory.URLByAppendingPathComponent("junkapp.sqlite")!.path 
NSFileManager.defaultManager().copyItemAtPath(
    path, toPath: destinationPath, error:nil) 

// Using 
coordinator!.addPersistentStoreWithType(NSSQLiteStoreType, 
    configuration: nil, URL: NSURL.fileURLWithPath(destinationPath), 
    options: nil, error: &error) 

Answer 2

這是爲我工作的最終代碼。請注意該部分//複製並記住，在運行此設置之前，您必須首先從設備或模擬器中刪除應用程序。

lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator? = { 
    // The persistent store coordinator for the application. This implementation creates and return a coordinator, having added the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail. 
    // Create the coordinator and store 
    var coordinator: NSPersistentStoreCoordinator? = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel) 
    let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("junkapp.sqlite") 
    var error: NSError? = nil 
    var failureReason = "There was an error creating or loading the application's saved data." 
    // Copying 
    let path = NSBundle.mainBundle().pathForResource("junkapp", ofType:"sqlite")! 
    NSFileManager.defaultManager().copyItemAtPath(path, toPath: url.path!, error:nil) 
    //end copy 
    if coordinator!.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: NSURL.fileURLWithPath(url.path!), options: nil, error: &error) == nil { 
     coordinator = nil 
     // Report any error we got. 
     let dict = NSMutableDictionary() 
     dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data" 
     dict[NSLocalizedFailureReasonErrorKey] = failureReason 
     dict[NSUnderlyingErrorKey] = error 
     //error = NSError.errorWithDomain("YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict) 
     // Replace this with code to handle the error appropriately. 
     // abort() 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. 
     NSLog("Unresolved error \(error), \(error!.userInfo)") 
     abort() 
    } 

    return coordinator 
}()