swift - 如何删除 CoreData Swift 3 中的所有实体对象

Question

所以我有这段代码可以正常工作，但我想要一个更好的代码。

func deleteCoreDataObjects() {
    let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext

    //where groupData is an Array of an Entity
    for i in 0..<self.groupData.count {
        context.delete(groupData[i])
    }


    (UIApplication.shared.delegate as! AppDelegate).saveContext()

}

目前我正在通过 for 循环一个一个地删除对象。

Answer 1

你可以试试这个:

func deleteAllData(entity: String)
{
    let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
    let managedContext = appDelegate.managedObjectContext
    let fetchRequest = NSFetchRequest(entityName: entity)
    fetchRequest.returnsObjectsAsFaults = false

    do 
    {
        let results = try managedContext.executeFetchRequest(fetchRequest)
        for managedObject in results
        {
            let managedObjectData:NSManagedObject = managedObject as! NSManagedObject
            managedContext.deleteObject(managedObjectData)
        }
    } catch let error as NSError {
        print("Detele all data in \(entity) error : \(error) \(error.userInfo)")
    }
}

用法:

self.deleteAllData("your_entityName")

已见于:https://stackoverflow.com/a/33931528/2894160