如何减少CNContacts的获取时间？

Question

您正在使用CNContacts来获取我的联系人，但需要大约两分钟才能显示swift中的所有联系人。有什么方法可以加快我的提取时间吗？

do
{
    try store.enumerateContactsWithFetchRequest(request)
    { contact, stop in
        contacts.append(contact)  
    }
}

catch
{
    print(error)
}

for contact in contacts
{
    let formatter = CNContactFormatter()
    formatter.style = .FullName
    if(((formatter.stringFromContact(contact))) != nil)
    {

        for phoneNumber:CNLabeledValue in contact.phoneNumbers
        {
            let number  = (contact.phoneNumbers[0].value as! CNPhoneNumber).valueForKey("digits") as! String
            let lable :String  =  CNLabeledValue.localizedStringForLabel(phoneNumber.label)
            if (lable.containsString("mobile"))
            {
                if((contact.emailAddresses.isEmpty))
                {
                    self.Allemail.addObject((""))
                }
                else
                {
                    self.Allemail.addObject((contact.emailAddresses[0].value))
                }

                self.Contactname=NSString(format:"'%@'",(formatter.stringFromContact(contact))!)
                let contactnumber=NSString(format:"'%@'",number)
                self.ContactsDictionary.addObject(self.Contactname)
                self.allNumbers.addObject(contactnumber as String)

            }

        }

        for i in 0..<self.ContactsDictionary.count
        {

            if(i == 0)
            {
                self.jsonstring = "[{'Name':\(self.ContactsDictionary.objectAtIndex(i)),'Number':\(self.allNumbers.objectAtIndex(i))}"
            }else
            {
                self.jsonstring = "\(self.jsonstring),{'Name':\(self.ContactsDictionary.objectAtIndex(i)),'Number':\(self.allNumbers.objectAtIndex(i))}"
            }


        }
        self.jsonstring = "\(self.jsonstring)]"

    }


}

self.contactupload()