IOS 联系邮政地址 Xamarin.Forms

Question

我正在 Xamarin.Forms 项目中编写 C# 应用程序，该项目显示联系人姓名和街道地址。 我无法从 CNContact 中提取地址并将联系人地址分配给字符串。

这将是显而易见的，但我被困住了！

    public List<Contact> GetContacts()
    {
        contactList = new List<Contact>();

        var store = new Contacts.CNContactStore();

        var ContainerId = new CNContactStore().DefaultContainerIdentifier;
        var predicate = CNContact.GetPredicateForContactsInContainer(ContainerId);

        var fetchKeys = new NSString[] { CNContactKey.Identifier, CNContactKey.GivenName, CNContactKey.FamilyName, CNContactKey.Birthday, CNContactKey.PostalAddresses, CNContactKey.ImageData };

        NSError error;

        var IPhoneContacts = store.GetUnifiedContacts(predicate, fetchKeys, out error);

        foreach(var c in IPhoneContacts)
        {
            var contact = new Contact();

            contact.FirstName = c.GivenName;
            contact.FamilyName = c.FamilyName;

            if(c.PostalAddresses.Length !=0)
            {
                contact.StreetAddress = CNPostalAddressFormatter.GetStringFrom(c.PostalAddresses, CNPostalAddressFormatterStyle.MailingAddress);
            };

            contactList.Add(contact);
        }

        return contactList;
    }

Answer 1

获取 iOS 中的现有联系人：

首先，您需要在Info.plist添加关注权限：

<key>NSContactsUsageDescription</key>  
<string>This app requires contacts access to function properly.</string>

其次，您可以创建一个 model 包含的需求联系信息如下：

public class ContactModel
{
    public IList PhoneNumbers { get; set; }
    public string GivenName { get; set; }
    public string FamilyName { get; set; }
}

第三，创建一个函数来获取信息：

public List<ContactModel> ReadContacts()
{
    var response = new List<ContactModel>();
    try
    {
        //We can specify the properties that we need to fetch from contacts  
        var keysToFetch = new[] {
    CNContactKey.PhoneNumbers, CNContactKey.GivenName, CNContactKey.FamilyName,CNContactKey.PostalAddresses,CNContactKey.PhoneNumbers
};
        //Get the collections of containers  
        var containerId = new CNContactStore().DefaultContainerIdentifier;
        //Fetch the contacts from containers  
        using (var predicate = CNContact.GetPredicateForContactsInContainer(containerId))
        {
            CNContact[] contactList;
            using (var store = new CNContactStore())
            {
                contactList = store.GetUnifiedContacts(predicate, keysToFetch, out
                    var error);
            }
            //Assign the contact details to our view model objects  
            response.AddRange(from item in contactList
                                where item?.EmailAddresses != null
                                select new ContactModel
                                {
                                    PhoneNumbers = item.PhoneNumbers,
                                    PostalAddresses = CNPostalAddressFormatter.GetStringFrom(item.PostalAddresses[0].Value, CNPostalAddressFormatterStyle.MailingAddress),
                                    GivenName = item.GivenName,
                                    FamilyName = item.FamilyName
                                });
        }
    }
    catch (Exception e)
    {
        Console.WriteLine(e);
        throw;
    }
    return response;
}

四、调用func：

List<ContactModel> contacts = ReadContacts();
ContactModel contactVm;
for (int i = 0; i < contacts.Count; i++)
{
    contactVm = contacts[i];
    Console.WriteLine("Contact is : " + contactVm.FamilyName);
    Console.WriteLine("Contact is : " + contactVm.GivenName);
    Console.WriteLine("Contact is : " + contactVm.PostalAddresses);
}

...
Contact is : Taylor
Contact is : David
Contact is : 1747 Steuart Street
Tiburon CA 94920
USA

五、截图如下：

====================================Udate============== ========================

您的代码应修改如下：

public List<Contact> GetContacts()
{
    contactList = new List<Contact>();

    var store = new Contacts.CNContactStore();

    var ContainerId = new CNContactStore().DefaultContainerIdentifier;
    var predicate = CNContact.GetPredicateForContactsInContainer(ContainerId);

    var fetchKeys = new NSString[] { CNContactKey.Identifier, CNContactKey.GivenName, CNContactKey.FamilyName, CNContactKey.Birthday, CNContactKey.PostalAddresses, CNContactKey.ImageData };

    NSError error;

    var IPhoneContacts = store.GetUnifiedContacts(predicate, fetchKeys, out error);

    foreach(var c in IPhoneContacts)
    {
        var contact = new Contact();

        contact.FirstName = c.GivenName;
        contact.FamilyName = c.FamilyName;

        if(c.PostalAddresses.Length !=0)
        {
            contact.StreetAddress = CNPostalAddressFormatter.GetStringFrom(c.PostalAddresses[0].Value, CNPostalAddressFormatterStyle.MailingAddress);
        };

        contactList.Add(contact);
    }

    return contactList;
}

方法CNPostalAddressFormatter.GetStringFrom的属性postalAddress是一种对象（ Contacts.CNPostalAddress ），但是c.PostalAddresses是一种 Array。

public static string GetStringFrom (Contacts.CNPostalAddress postalAddress, Contacts.CNPostalAddressFormatterStyle style);

Answer 2

问题是CNPostalAddressFormatter.GetStringFrom()方法需要一个CNPostalAddress object 作为参数，但您传递的是单个联系人的所有地址，因为PostalAddresses属性是一个CNLabeledValue<ValueType>对象的数组。

您应该做的是遍历所有地址，或者默认情况下只取第一个地址。 真的取决于你想要达到的目标。

例如，这将获得第一个CNPostalAddress ：

contact.StreetAddress = CNPostalAddressFormatter.GetStringFrom(c.PostalAddresses[0].Value, CNPostalAddressFormatterStyle.MailingAddress);

此外，如果您想知道地址（家庭、工作等）的 label，您可以这样获取：

c.PostalAddresses[0].Label

那么实际的CNPostalAddress object 又是这样的：

c.PostalAddresses[0].Value