我得到了错误:
1:EXC_BAD_INSTRUCTION(code=EXC_I386_INVOP,subcode=0*0)
我是编码新手,我正在关注此视频 https://www.youtube.com/watch?v=Fv-A8lKn7VY
代码如下:
import UIKit
import CoreData
class SwiftCoreDataHelper: NSObject {
class func directoryForDatabaseFilename()->NSString{
return NSHomeDirectory().stringByAppendingString("/Library/Private Documents")
}
class func databaseFilename()->NSString{
return "database.sqlite";
}
class func managedObjectContext()->NSManagedObjectContext{
do { try NSFileManager.defaultManager().createDirectoryAtPath(SwiftCoreDataHelper.directoryForDatabaseFilename() as String, withIntermediateDirectories: true, attributes: nil) }
catch {
print("Error Creating Directory for DB")
}
// NSFileManager.defaultManager().createDirectoryAtPath(SwiftCoreDataHelper.directoryForDatabaseFilename(), withIntermediateDirectories: true, attributes: nil, error: &error)
let path:NSString = "\(SwiftCoreDataHelper.directoryForDatabaseFilename()) + \(SwiftCoreDataHelper.databaseFilename())"
let url:NSURL = NSURL(fileURLWithPath: path as String)
let managedModel:NSManagedObjectModel = NSManagedObjectModel.mergedModelFromBundles(nil)!
let storeCoordinator:NSPersistentStoreCoordinator = NSPersistentStoreCoordinator(managedObjectModel: managedModel)
do {
try storeCoordinator.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil)
}
catch {
print("Error: \(error)")
}
let managedObjectContext = NSManagedObjectContext(concurrencyType: NSManagedObjectContextConcurrencyType.MainQueueConcurrencyType)
managedObjectContext.persistentStoreCoordinator = storeCoordinator
return managedObjectContext
}
class func insertManagedObject(className:NSString, managedObjectConect:NSManagedObjectContext)->AnyObject{
let managedObject:NSManagedObject = NSEntityDescription.insertNewObjectForEntityForName(className as String, inManagedObjectContext: managedObjectConect) as NSManagedObject
return managedObject
}
class func saveManagedObjectContext(managedObjectContext:NSManagedObjectContext)->Bool{
do {
try managedObjectContext.save()
return true
} catch _ {
return false
}
}
class func fetchEntities(className:NSString, withPredicate predicate:NSPredicate?, managedObjectContext:NSManagedObjectContext)->NSArray{
let fetchRequest:NSFetchRequest = NSFetchRequest()
let entetyDescription:NSEntityDescription = NSEntityDescription.entityForName(className as String, inManagedObjectContext: managedObjectContext)!
fetchRequest.entity = entetyDescription
if (predicate != nil){
fetchRequest.predicate = predicate!
}
fetchRequest.returnsObjectsAsFaults = false
var items = NSArray()
do { items = try managedObjectContext .executeFetchRequest(fetchRequest)
} catch {
print("Fetch Request Failed")
}
return items
}
}
产生错误的代码是:
let entetyDescription:NSEntityDescription = NSEntityDescription.entityForName(className as String, inManagedObjectContext: managedObjectContext)!
我无法纠正错误。
Best Answer-推荐答案 strong>
entityForName 返回一个可选值。它可能崩溃了,因为您使用 ! 强制解包此操作的结果
在这种情况下,您可以使用 可选绑定(bind) 来测试 entityForName 是否真的返回值:
if let entityDescription = NSEntityDescription.entityForName(className as String, inManagedObjectContext: managedObjectContext) {
// work with entityDescription
} else {
// handle the case in which entityForName returns nil
}
关于ios - 线程 1 :EXC_BAD_INSTRUCTION(code=EXC_I386_INVOP, 子代码=0*0) 错误,我们在Stack Overflow上找到一个类似的问题:
https://stackoverflow.com/questions/38956610/
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