ReactiveUI与验证

Question

在使用ReactiveUI执行数据验证时，什么是“最佳实践”？假设我有一个视图模型，如下所示：

public class MyViewModel: ReactiveObject
{
    public ReactiveAsyncCommand SaveMyDataCommand { get; protected set; }

    private string _email;
    public string Email
    {
        get { return _email; }
        set
        {
          _email = value;
          raisePropertyChanged("Email");
        }
    }

    private string _name;
    public string Name
    {
        get { return _name; }
        set
        {
          _name= value;
          raisePropertyChanged("Name");
        }
    }

    private bool _sendEmail = false;
    public bool SendEmail
    {
        get { return _sendEmail; }
        set
        {
          _sendEmail = value;
          raisePropertyChanged("SendEmail");
        }
    }  

    public MyViewModel()
    {
        SaveMyDataCommand = new ReactiveAsyncCommand(null, 1);
    }
}

下面是我要验证的内容：

1. If SendEmail == true然后确保电子邮件属性中有一个有效的电子邮件地址。(我并不担心实际的电子邮件地址验证部分本身。)
2. 如果将值设置为Email属性，请确保它是有效的电子邮件地址。如果
3. (如果验证失败)，则SaveMyDataCommand不应该是可执行的。

我只是在寻找一个很好的例子，说明如何使用ReactiveUI进行简单/稍微复杂的数据验证。有人能解释一下这件事吗？

Answer 1

对于任何想要寻找使用ReactiveValidatedObject的例子的人来说，下面是对我有用的方法。请注意，您还必须向类中添加对System.ComponentModel的引用。

public class MyViewModel: ReactiveValidatedObject
{
  public ReactiveAsyncCommand SaveMyDataCommand { get; protected set; }

  // THIS PROPERTY INDICATES WHETHER ALL FIELDS HAVE BEEN VALIDATED
  public bool IsSaveEnabled
  {
    get { return IsObjectValid(); }
  }

  private string _email;
  [ValidatesViaMethod(AllowBlanks=true,AllowNull=true,Name="IsEmailValid",ErrorMessage="Please enter a valid email address")]
  public string Email
  {
    get { return _email; }
    set
    {
      _email = value;
      raisePropertyChanged("Email");
      SendEmail = SendEmail;
      raisePropertyChanged("IsSaveEnabled");
    }
  }

  private string _name;
  public string Name
  {
    get { return _name; }
    set
    {
      _name= value;
      raisePropertyChanged("Name");
    }
  }

  private bool _sendEmail = false;
  [ValidatesViaMethod(Name = "IsSendEmailValid", ErrorMessage = "Make sure a valid email address is entered.")]
  public bool SendEmail
  {
    get { return _sendEmail; }
    set
    {
      _sendEmail = value;
      raisePropertyChanged("SendEmail");
      raisePropertyChanged("IsSaveEnabled");
    }
  }  

  public bool IsEmailValid(string email)
  {
    if (string.IsNullOrEmpty(email))
    {
      return true;
    } 

    // Return result of Email validation
  }

  public bool IsSendEmailValid(bool sendEmail)
  {
     if (sendEmail)
     {
       if (string.IsNullOrEmpty(Email))
       {
         return false;
       }

       // Return result of Email validation
     }
  }

  public MyViewModel()
  {
    SaveMyDataCommand = new ReactiveAsyncCommand(null, 1);
  }
}

我希望这对某人有帮助！)

Answer 2

使用ReactiveValidatedObject，然后使用数据注释(在电话中，对短消息表示歉意)