当我尝试以下LINQ过滤器
时 var productsInfo = from product in productsElement.Descendants("product").Filter(rule)
from photo in product.Descendants("photo")
from parameter in product.Descendants("parameter")
let id = product.Attribute("id")
let addr = photo.Attribute("addr")
let name = parameter.Attribute("name")
select new { ID = id.Value, Addr = addr.Value, Name = name.Value };
我收到以下错误：
The given ruleset does not contain any rules with type
System.Xml.Linq.XElement, System.Xml.Linq, Version=4.0.0.0, Culture=neutral,
PublicKeyToken=b77a5c561934e089 (Error E106)
我的规则：
<?xml version="1.0" encoding="utf-8"?><codeeffects xmlns="http://codeeffects.com/schemas/rule/41" xmlns:ui="http://codeeffects.com/schemas/ui/4"><rule id="09973a56-3d6a-4616-ae1c-40d0d17e95b9" webrule="4.3.6.7" utc="2017-07-24T10:07:08.6346" type="testSlimWebRule.products, testSlimWebRule, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" eval="true"><definition><condition type="equal"><property name="AllProducts.product.id" /><value type="numeric">1</value></condition></definition><format><lines /></format></rule></codeeffects>
XML：
XDocument productsElement = XDocument.Parse(@"<products>
<AllProducts>
<product id='1'>
<photo addr='1.jpg'/>
<parameter name='name'/>
</product>
<product id='2'>
<photo addr='2.jpg'/>
<parameter name='Kenneth'/>
</product>
</AllProducts>
</products> ");
使用Visual Studio“Insert as XML class”生成的products类：
namespace testSlimWebRule
{
/// <remarks/>
[System.SerializableAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
[System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
[System.Xml.Serialization.XmlRootAttribute(Namespace = "", IsNullable = false)]
public partial class products
{
private productsAllProducts allProductsField;
/// <remarks/>
public productsAllProducts AllProducts
{
get
{
return this.allProductsField;
}
set
{
this.allProductsField = value;
}
}
}
/// <remarks/>
[System.SerializableAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
[System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
public partial class productsAllProducts
{
private productsAllProductsProduct productField;
/// <remarks/>
public productsAllProductsProduct product
{
get
{
return this.productField;
}
set
{
this.productField = value;
}
}
}
/// <remarks/>
[System.SerializableAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
[System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
public partial class productsAllProductsProduct
{
private productsAllProductsProductPhoto photoField;
private productsAllProductsProductParameter parameterField;
private byte idField;
/// <remarks/>
public productsAllProductsProductPhoto photo
{
get
{
return this.photoField;
}
set
{
this.photoField = value;
}
}
/// <remarks/>
public productsAllProductsProductParameter parameter
{
get
{
return this.parameterField;
}
set
{
this.parameterField = value;
}
}
/// <remarks/>
[System.Xml.Serialization.XmlAttributeAttribute()]
public byte id
{
get
{
return this.idField;
}
set
{
this.idField = value;
}
}
}
/// <remarks/>
[System.SerializableAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
[System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
public partial class productsAllProductsProductPhoto
{
private string addrField;
/// <remarks/>
[System.Xml.Serialization.XmlAttributeAttribute()]
public string addr
{
get
{
return this.addrField;
}
set
{
this.addrField = value;
}
}
}
/// <remarks/>
[System.SerializableAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
[System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
public partial class productsAllProductsProductParameter
{
private string nameField;
/// <remarks/>
[System.Xml.Serialization.XmlAttributeAttribute()]
public string name
{
get
{
return this.nameField;
}
set
{
this.nameField = value;
}
}
}
}
ASP.net部分：
<rule:RuleEditor ID="ruleEditor" runat="server"
Mode="Filter"
ShowToolBar="false"
SourceAssembly="testSlimWebRule"
SourceType="testSlimWebRule.products" />
我尝试了几种设置过滤器的组合，但却找不到解决方案。
我错过了什么？
答案 0 :(得分：1)
Filter（）扩展程序接受一组对象，并分别针对给定规则对其进行评估。规则引擎采用一种集合的元素，并使用它来编译具有该类型参数的lambda。
List<MyClass> list = new List<MyClass>();
list.Filter(rule);
在此示例中，规则的类型为 MyClass ，它将应用于列表中的每个对象，类似于：
Evaluator<MyClass> ev = new Evaluator<MyClass>(rule);
foreach (var item in list)
{
ev.Evaluate(item);
}
您可以在CodeEffects文档页面上阅读更多内容：Rule-Based Data Filtering Using LINQ to Object Provider。
在你的例子中，你犯了一些错误：
以下示例将演示四种可能的选项，第一种是最佳选择。
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Xml.Linq;
using System.Xml.Serialization;
using CodeEffects.Rule.Core;
namespace testSlimWebRule
{
class Program
{
/* Output:
* Option A: 1, Bob, 1.jpg
* Option B: 1, Bob, 1.jpg
* Option C: 1, Bob, 1.jpg
* Option D: 2, Kenneth, 2.jpg
*/
static void Main(string[] args)
{
string xml =
@"<products>
<AllProducts>
<product id='1'>
<photo addr='1.jpg'/>
<parameter name='Bob'/>
</product>
<product id='2'>
<photo addr='2.jpg'/>
<parameter name='Kenneth'/>
</product>
</AllProducts>
</products>";
XDocument dom = XDocument.Parse(xml);
products products;
//You need to load auto-generated classes. I prefer serialization. You may parse XML elements individually.
using (var xmlReader = dom.CreateReader())
{
var serializer = new XmlSerializer(typeof(products));
products = (products)serializer.Deserialize(xmlReader);
}
string productsProductRule = File.ReadAllText("rule1.xml");
//A: Filter productsProduct[]; result is IEnumerable<productsProduct>.
//This rule evaluates objects of the productsProduct type.
var filteredProducts = products.AllProducts.Filter(productsProductRule);
foreach (var product in filteredProducts)
Console.WriteLine("Option A: {0}, {1}, {2}", product.id, product.parameter.name, product.photo.addr);
string xElementRule = File.ReadAllText("rule2.xml");
//B: Filter IEnumerable<XElement>; result is IEnumerable<XElement>.
//This rule evaluates objects of the XElement type.
var filteredElements = dom.Descendants("product").Filter(xElementRule);
foreach (var element in filteredElements)
Console.WriteLine("Option B: {0}, {1}, {2}", element.Attribute("id").Value, element.Element("parameter").Attribute("name").Value, element.Element("photo").Attribute("addr").Value);
//C: Filter IEnumerable<XElement>; result is IEnumerable<'a> (anonymous)
//This rule also evaluates objects of the XElement type.
var productsInfo = from product in dom.Descendants("product").Filter(xElementRule)
from photo in product.Descendants("photo")
from parameter in product.Descendants("parameter")
let id = product.Attribute("id")
let addr = photo.Attribute("addr")
let name = parameter.Attribute("name")
select new
{
ID = id.Value,
Addr = addr.Value,
Name = name.Value
};
foreach (var info in productsInfo)
Console.WriteLine("Option C: {0}, {1}, {2}", info.ID, info.Name, info.Addr);
string anonymousRule = File.ReadAllText("rule3.xml");
//D: Filter IEnumerable<'a>; result is IEnumerable<'a>
//This rule evaluates objects of the anonymous type 'a with properties ID, Addr, and Name.
var productsInfo2 = (from product in dom.Descendants("product")
from photo in product.Descendants("photo")
from parameter in product.Descendants("parameter")
let id = product.Attribute("id")
let addr = photo.Attribute("addr")
let name = parameter.Attribute("name")
select new
{
ID = id.Value,
Addr = addr.Value,
Name = name.Value
})
.Filter(anonymousRule);
foreach (var info in productsInfo2)
Console.WriteLine("Option D: {0}, {1}, {2}", info.ID, info.Name, info.Addr);
}
}
}
您需要重新粘贴XML示例以生成正确的数组字段。您拥有的是使用只有一条记录的XML示例生成的。但是要过滤，您需要一个集合。
using System;
namespace testSlimWebRule
{
/// <remarks/>
[System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
[System.Xml.Serialization.XmlRootAttribute(Namespace = "", IsNullable = false)]
public partial class products
{
private productsProduct[] allProductsField;
/// <remarks/>
[System.Xml.Serialization.XmlArrayItemAttribute("product", IsNullable = false)]
public productsProduct[] AllProducts
{
get
{
return this.allProductsField;
}
set
{
this.allProductsField = value;
}
}
}
/// <remarks/>
[System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
public partial class productsProduct
{
private productsProductPhoto photoField;
private productsProductParameter parameterField;
private byte idField;
/// <remarks/>
public productsProductPhoto photo
{
get
{
return this.photoField;
}
set
{
this.photoField = value;
}
}
/// <remarks/>
public productsProductParameter parameter
{
get
{
return this.parameterField;
}
set
{
this.parameterField = value;
}
}
/// <remarks/>
[System.Xml.Serialization.XmlAttributeAttribute()]
public byte id
{
get
{
return this.idField;
}
set
{
this.idField = value;
}
}
}
/// <remarks/>
[System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
public partial class productsProductPhoto
{
private string addrField;
/// <remarks/>
[System.Xml.Serialization.XmlAttributeAttribute()]
public string addr
{
get
{
return this.addrField;
}
set
{
this.addrField = value;
}
}
}
/// <remarks/>
[System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
public partial class productsProductParameter
{
private string nameField;
/// <remarks/>
[System.Xml.Serialization.XmlAttributeAttribute()]
public string name
{
get
{
return this.nameField;
}
set
{
this.nameField = value;
}
}
}
}
此规则具有正确类型 testSlimWebRule.productsProduct 。它将根据 testSlimWebRule.productsProduct 的自动生成数组中的每个元素进行评估。
<?xml version="1.0" encoding="utf-8"?>
<codeeffects xmlns="http://codeeffects.com/schemas/rule/41" xmlns:ui="http://codeeffects.com/schemas/ui/4">
<rule id="09973a56-3d6a-4616-ae1c-40d0d17e95b9" webrule="4.3.6.7" utc="2017-07-24T10:07:08.6346" type="testSlimWebRule.productsProduct, testSlimWebRule, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" eval="true">
<definition>
<condition type="equal">
<property name="id" />
<value type="numeric">1</value>
</condition>
</definition>
</rule>
</codeeffects>
这条规则就是你的方式。它适用于 System.Xml.Linq.XElement 类型的对象。因此，它只能对该类型的属性和方法进行操作，即您不会获得自定义字段id，addr，name等。
<?xml version="1.0" encoding="utf-8"?>
<codeeffects xmlns="http://codeeffects.com/schemas/rule/41" xmlns:ui="http://codeeffects.com/schemas/ui/4">
<rule id="e38da351-1190-47fb-b99b-d06787c9a459" webrule="4.3.6.7" utc="2017-07-24T10:07:08.6346" type="System.Xml.Linq.XElement, System.Xml.Linq, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" eval="true">
<definition>
<condition type="equal">
<property name="FirstAttribute.Value" />
<value>1</value>
</condition>
</definition>
</rule>
</codeeffects>
此规则没有任何类型。相反，它接收它所评估的任何类型。在示例中，它获取匿名类型＆＃39; a ，因此它可以对属性ID，名称和地址进行操作。
<?xml version="1.0" encoding="utf-8"?>
<codeeffects xmlns="http://codeeffects.com/schemas/rule/41" xmlns:ui="http://codeeffects.com/schemas/ui/4">
<rule id="7d72463f-5ae2-4617-a2bf-fd605fcb4f54" webrule="4.3.6.7" utc="2017-07-24T10:07:08.6346" type="" eval="true">
<definition>
<condition type="startsWith">
<property name="Addr" />
<value>2</value>
</condition>
</definition>
</rule>
</codeeffects>