我使用实现 IDataErrorInfo 接口WPF数据与实体的结合。一般我code是这样的：

I use WPF data binding with entities that implement IDataErrorInfo interface. In general my code looks like this:

商业实体：

public class Person : IDataErrorInfo 
{
  public string Name { get; set;}

  string IDataErrorInfo.this[string columnName]
  {
    if (columnName=="Name" && string.IsNullOrEmpty(Name))
      return "Name is not entered";
    return string.Empty;
  }  
}

XAML文件：

Xaml file:

<TextBox Text="{Binding Path=Name, Mode=TwoWay, ValidatesOnDataErrors=true}" />

当用户点击创建新的人以下code执行：

When user clicks on "Create new person" following code is executed:

DataContext = new Person();

现在的问题是，这只是创造人的时候它的名称是空的和WPF的立即绘制红色边框，并显示错误信息。我希望它只是显示错误时的名字已经被编辑，焦点将丢失。有谁知道这样做的方法是什么？

The problem is that when person is just created its name is empty and WPF immediately draws red frame and shows error message. I want it to show error only when name was already edited and focus is lost. Does anybody know the way to do this?

推荐答案

您可以更改您的个人类射击验证错误只有名称属性已发生更改：

You can change your person class to fire validation error only if Name property was ever changed:

public class Person : IDataErrorInfo {

    private bool nameChanged = false;
    private string name;
    public string Name {
        get { return name; }
        set { 
            name = value;
            nameChanged = true;
        }
    }

//... skipped some code

    string IDataErrorInfo.this[string columnName] {
        get {
            if(nameChanged && columnName == "Name" && string.IsNullOrEmpty(Name)) 
                return "Name is not entered"; 
            return string.Empty;
        }
    }
}