//修改代码xxxxx：
//BlogEngine.Core.Category.cs

private string _Title;
/// <summary>
/// Gets or sets the Title or the object.
/// </summary>
public string Title
{
    get { return _Title; }
    set
    {
        if (_Title != value) MarkChanged("Title");
        _Title = value;
    }
}
//后添加：
private string _Slug;
/// <summary>
/// Gets or sets the Slug or the object.
/// </summary>
public string Slug
{
    get { return _Slug; }
    set
    {
        if (_Slug != value) MarkChanged("Slug");
        _Slug = value;
    }
}
public Category(string title, string description,string slug)
{
    this.Id = Guid.NewGuid();
    this._Title = title;
    this._Description = description;
    this._Slug = slug;
    this.Parent = null;
}