当子类属性改变时，通知父类

Question

我必须查看ViewModels, OrganizationContact和PersonalInformationModel。

OrganizationContact使用PersonalInformationModel。

它们是这样设置的:

OrganizationContact:

public class OrganizationContact : ViewModelBase
{
    private PersonalInformationModel _contactInfo;
    public PersonalInformationModel ContactInfo
    {
        get
        {
            return _contactInfo;
        }
        set
        {
            _contactInfo = value;
            RaisePropertyChanged(nameof(ContactHeader), "", "", true);
            RaisePropertyChanged(nameof(ContactInfo), null, _contactInfo, true);
        }
    }
    //Generate Header
    public string ContactHeader
    {
        get
        {
            var header = "";
            if (!string.IsNullOrWhiteSpace(ContactInfo.Title?.TitleAbbreviation))
            {
                header += ContactInfo.Title.TitleAbbreviation + " ";
            }
            if (!string.IsNullOrWhiteSpace(ContactInfo.FirstName))
            {
                header += ContactInfo.FirstName + " ";
            }
            if (!string.IsNullOrWhiteSpace(ContactInfo.MiddleInitial))
            {
                header += ContactInfo.MiddleInitial + ". ";
            }
            if (!string.IsNullOrWhiteSpace(ContactInfo.LastName))
            {
                header += ContactInfo.LastName + " ";
            }
            return header;
        }
    }
    public int OrganizationLink { get; set; }
    public string Position { get; set; }
    public int Priority { get; set; }
}

PersonalInformationModel:

public class PersonalInformationModel : ViewModelBase
{
    private string _firstName;
    private string _middleInitial;
    private string _lastName;
    private string _phoneNumber;
    private string _phoneExtension;
    private string _faxNumber;
    private string _email;
    public int PersonalIdentity { get; set; }
    public string FirstName
    {
        get
        {
            return _firstName;
        }
        set
        {
            _firstName = value;
            RaisePropertyChanged(nameof(FirstName), "", _firstName, true);
        }
    }
    public string MiddleInitial
    {
        get
        {
            return _middleInitial;
        }
        set
        {
            _middleInitial= value;
            RaisePropertyChanged(nameof(MiddleInitial),"",_middleInitial,true);
        }
    }
    public string LastName
    {
        get
        {
            return _lastName;
        }
        set
        {
            _lastName = value;
            RaisePropertyChanged(nameof(LastName), "", _lastName, true);
        }
    }
    public string PhoneNumber
    {
        get
        {
            return _phoneNumber;
        }
        set
        {
            _phoneNumber = value;
            RaisePropertyChanged(nameof(PhoneNumber), "", _phoneNumber, true);
        }
    }
    public string PhoneExtension
    {
        get
        {
            return _phoneExtension;
        }
        set
        {
            _phoneExtension = value;
            RaisePropertyChanged(nameof(PhoneExtension), "", _phoneExtension, true);
        }
    }
    public string FaxNumber
    {
        get
        {
            return _faxNumber;
        }
        set
        {
            _faxNumber = value;
            RaisePropertyChanged(nameof(FaxNumber), "", _faxNumber, true);
        }
    }
    public string Email
    {
        get
        {
            return _email;
        }
        set
        {
            _email = value;
            RaisePropertyChanged(nameof(Email),"",_email, true);
        }
    }
    public string FullName => $"{FirstName} {LastName}";
}

PersonalInformationModel被其他类使用。

我正在寻找的是OrganizationContact被告知的方法，如果PersonalInformationModel内部的任何属性发生变化，那么OrganizationContact内部的ContactHeader可以被通知变化。

Answer 1

好的，为了得到你想要的，你需要做一些事情。首先，当您在OrganizationContact上设置ContactInfo属性时，注册PropertyChanged处理程序:

public PersonalInformationModel ContactInfo
{
    get
    {
        return _contactInfo;
    }
    set
    {
        if (_contactInfo != null)
        {
           _contactInfo.PropertyChanged -= ContactInfo_PropertyChanged;
        }
        _contactInfo = value;
        if (_contactInfo != null)
        {
           _contactInfo.PropertyChanged += ContactInfo_PropertyChanged
        }
        RaisePropertyChanged(nameof(ContactInfo), null, _contactInfo, true);
    }
}

现在，创建处理程序。你应该能够在ContactHeader上引发PropertyChanged事件来更新你的绑定。

void ContactInfo_PropertyChanged(object sender, PropertyChangedEventArgs args)
{
    RaisePropertyChanged(nameof(ContactHeader), "", "", true);
}