c# - 从属性值中获取属性

Question

有这个简单的类:

public class Book
{
    [DataMember]
    [Column("Bok_Name")]
    [Author("AuthorName")]
    public string Name{ get; set; }

    [DataMember]
    [Column("Bok_Publisher")]
    public string Publisher{ get; set; }
}

在知道属性类型为 Column 且值为 Bok_Name 的情况下，如何从属性中获取 PropertyInfo。我试图用 linq 查询来做到这一点。

Answer 1

使用反射和 .NET 扩展 CustomAttributeExtensions.GetCustomAttribute{T}方法，您可以找到具有自定义属性的属性。在这种情况下，自定义属性来自 System.ComponentModel.DataAnnotations.Schema.ColumnAttribute。

var book = new Book { Name = "Jitterbug Perfume" };

PropertyInfo bokName = typeof(Book)
    .GetProperties(BindingFlags.Public | BindingFlags.Instance) // add other bindings if needed
    .FirstOrDefault(x => x.GetCustomAttribute<ColumnAttribute>() != null
       && x.GetCustomAttribute<ColumnAttribute>().Name.Equals("Bok_Name", StringComparison.OrdinalIgnoreCase));

// the above query only gets the first property with Column attribute equal to "Bok_Name"
// if there are more than one, then use a .Where clause instead of FirstOrDefault.
if (bokName != null)
{
    string name = bokName.GetValue(book).ToString();
    // do other stuff
}