如何在CodeAttribute中获取属性值 [英] How get Attribute Value in CodeAttribute

问题描述

我编写了一种按属性获取属性值的方法:

I wrote a method to get Attribute Value By Property:

public string GetAttributeValueByNameAttributeAndProperty(CodeClass cc, string nameAttribute, string nameProperty)
{
    var value = "";
    foreach(CodeAttribute ca in cc.Attributes) 
            { 
                if(ca.Name.Contains(nameAttribute) && ca.Value.Contains(nameProperty))
                {
                    value = ca.Value.Remove(0,ca.Value.IndexOf(nameProperty));
                    value = value.Replace(" ","");
                    if(value.Contains(","))
                        value = value.Remove(ca.Value.IndexOf(","));
                }
            }

     return value;
}

例如: 我有属性[Map(Name = "MenuItem, Availability" )]

我叫GetAttributeValueByNameAttributeAndProperty(codeclass，"Map"，"Name") 在该方法之后，获取CodeAttribute.Value并返回字符串:Name ="MenuItem，Availability" 在我删除"Name ="和多余的字符并用，"分隔后

I call GetAttributeValueByNameAttributeAndProperty( codeclass, "Map" , "Name") After that method get CodeAttribute.Value and return string: Name = "MenuItem, Availability" After I remove "Name = " and extra characters and Split by ","

但是我的高级程序员告诉我，这种方法不灵活，我需要找到一种更方便的方法来获取CodeAttribute.Value中的内部数据.

But my Senior Programmer told me that this method is inflexible and I need to find a more convenient way get inner data in CodeAttribute.Value.

您有什么想法/例子吗?

Do you have any ideas / examples?

推荐答案

您可以使用 CodeClass.Attributes 属性以获取类的属性.每个属性的类型为 CodeAttribute ，并具有 Name 和 CodeAttributeArgument ，其中具有 Name 和

You can use CodeClass.Attributes property to get attributes of a class. Each attribute is of type of CodeAttribute and has a Name and a Children property which contains arguments of the attribute. Each argument is of type of CodeAttributeArgument which has Name and Value properties.

示例

现在，您拥有从CodeAttribute获取属性值所需的所有信息.这是一个例子.我已经用[MySample(Property1 = "Something")]属性装饰了Program类

Now you have all information which you need to get attribute value from CodeAttribute. Here is an example. I've decorated Program class with a [MySample(Property1 = "Something")] attribute

using System;
namespace ConsoleSample
{
    [MySample(Property1 = "Something")]
    class Program
    {
        static void Main(string[] args)
        {
        }
    }
    public class MySampleAttribute : Attribute
    {
        public string Property1 { get; set; }
    }
}

这是示例T4模板:

<#@ template debug="true" hostSpecific="true" #>
<#@ output extension=".txt" #>
<#@ assembly Name="System.Core" #>
<#@ assembly name="EnvDte" #>
<#@ assembly name="EnvDte80" #>
<#@ import namespace="System" #>
<#@ import namespace="System.Linq" #>
<#@ import namespace="System.Collections.Generic" #> 
<#@ import namespace="EnvDTE" #> 
<#@ import namespace="EnvDTE80" #> 
<#    
var env = (this.Host as IServiceProvider).GetService(typeof(EnvDTE.DTE)) as EnvDTE.DTE;
var project = env.Solution.FindProjectItem(this.Host.TemplateFile).ContainingProject
    as EnvDTE.Project;
var codeClass = project.ProjectItems.Item("Program.cs").FileCodeModel.CodeElements
                       .OfType<CodeNamespace>().ToList()[0]
                       .Members.OfType<CodeClass>().ToList()[0];
var attribute = codeClass.Attributes.Cast<CodeAttribute>()
                         .Where(a=>a.Name=="MySample").FirstOrDefault();
if(attribute!=null)
{
    var property = attribute.Children.OfType<CodeAttributeArgument>()
                            .Where(a=>a.Name=="Property1").FirstOrDefault();
    if(property!=null)
    {
        var value = property.Value;
        WriteLine(value);
    }
}
#>

如果运行模板，您将在输出中收到"Something".

If you run the template, you will receive "Something" in output.

这篇关于如何在CodeAttribute中获取属性值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！