MVC自定义类型的属性没有在我的模型绑定 [英] MVC Custom type property is not binding in my model

问题描述

我有以下情形：C＃基地项目，由该公司所有其他项目使用的所有数据域（自定义类型）。所以，一个汇入作业有点难以修改。

I have the following scenario: A C# base project, with all data domains (custom types) that are used by all others projects in the company. So, It´s a little bit hard to modify it.

现在，我们正在创造我们与基地项目作为参照第一MVC项目和模型绑定不工作的那些字符串自定义类型的属性：

Now, we are creating our first mvc project with that base project as reference, and the model binding doesnt work for properties of those strings custom types:

    [Serializable]
    [TypeConverter(typeof(ShortStrOraTypeConverter))]
    public class ShortStrOra : BaseString
    {
        public ShortStrOra()
            : this(String.Empty)
        {           
        }

        public ShortStrOra(string stringValue)
            : base(stringValue, 35)
        {
        }

        public static implicit operator ShortStrOra(string stringValue)
        {
            return new ShortStrOra(stringValue);
        }

        public static implicit operator string(ShortStrOra value)
        {

            if (value == null)
            {
                return null;
            }
            else
            {
                return value.ToString();
            }
        }

        public void Add(object o)
        { 
        }
    }

该类型转换器：

    public class ShortStrOraTypeConverter : TypeConverter
    {
        public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
        {
            if (sourceType == typeof(string))
                return true;
            return base.CanConvertFrom(context, sourceType);
        }

        public override object ConvertFrom(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value)
        {
            if (value is string)
                return new ShortStrOra(Convert.ToString(value));
            return base.ConvertFrom(context, culture, value);
        }

        public override object ConvertTo(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value, Type destinationType)
        {
            if (destinationType == typeof(string))
                return ((ShortStrOra)value).ToString();

            return base.ConvertTo(context, culture, value, destinationType);
        }
    }

在我简单的测试，这种单一类的名称属性没有被绑定，但姓氏了。

And in my simple test, with this single class, the Name property has not been binded, but Lastname has.

public class TesteModel
{

    public ShortStrOra Name {get; set;}
    public String Lastname { get; set; }
    public TesteModel() { }

}

我的观点：

@using (Html.BeginForm("EditMember", "Home", FormMethod.Post, new { @id = "frmEditMembers" }))
{
    @Html.TextBoxFor(m => m.Name)<br />
    @Html.TextBoxFor(m => m.Lastname)
    <input type="submit" value="Salvar" />
}

我的控制器：

public ActionResult EditMember(TesteModel model)
{
    return View("Index", model);
}

最后，问题出在哪里？序列化？模型绑定？转换器？我不知道去哪里。没有任何错误或异常。

Finally, where is the problem? Serialization? Model binding? Converter? I dont know where to go. There is no error or exception.

任何ideias？
谢谢

Any ideias? Thanks

推荐答案

我找到了。我读了有关自定义模型绑定，然后解决了我的问题，这个办法：

I found it. I read about custom model binding and then solved my problem with this approach:

创建一个新的类，覆盖模型绑定，并检查是否属性是自定义类型，然后对其进行初始化。

Creating a new class, to override model binding, and checking if the property is of the custom type and then initializes it.

public class TesteModelBinder2 : DefaultModelBinder
{
    protected override void BindProperty(ControllerContext controllerContext, ModelBindingContext bindingContext, System.ComponentModel.PropertyDescriptor propertyDescriptor)
    {
          NameValueCollection values = controllerContext.HttpContext.Request.Form;

          if (propertyDescriptor.PropertyType.Equals(typeof(ShortStrOra)))
          {
              ShortStrOra value = new ShortStrOra(values[propertyDescriptor.Name]);
              propertyDescriptor.SetValue(bindingContext.Model, value);
              return;
          }
          else 
            base.BindProperty(controllerContext, bindingContext, propertyDescriptor);
    }
}

有什么解决的问题是这一行：

What solved the problem was this line:

ShortStrOra value = new ShortStrOra(values[propertyDescriptor.Name]);

如果没有它的时候尝试设置我的ShortStrOra类型的字符串值，发动机抛出一个CastException，但它静静地死了，一个空值设置好的的属性。

Without it the engine throws a CastException when tries to set a string value on my ShortStrOra type, but it dies silently and a null value is setted on the property.

要在控制器使用自定义的模型绑定：

To use the custom model binder in controller:

[HttpPost]
public ActionResult EditMember([ModelBinder(typeof(TesteModelBinder2))]TesteModel model)
    {
        return View("Index", model);
    }

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