entityMap|0|type|LINK|mutability|MUTABLE|data|url|https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/concepts/attributes/accessing-attributes-by-using-reflection|1|https://docs.microsoft.com/en-us/dotnet/api/system.reflection.customattributedata.constructor?view=netframework-4.7.2|blocks|key|ajhhl|text|这主要取决于您正在查看的属性以及它的编码方式。请看下面的代码，作为如何执行您所要求的操作的示例。|unstyled|depth|inlineStyleRanges|entityRanges|23hk6|//The+attribute+we're+looking+at
public+class+MyAtt+:+System.Attribute
{
++++public+string+name;
++++public+string+anotherstring;

++++public+MyAtt(string+name,+string+anotherstring)
++++{
++++++++this.name+=+name;
++++++++this.anotherstring+=+anotherstring;
++++}
}

public+static+class+Usage
{
++++[MyAtt("String1",+"String2")]+//Using+the+attribute
++++public+static+string+SomeProperty+=+"String1";
}

public+static+class+Program
{
++++public+static+void+Main()
++++{
++++++++Console.WriteLine(IsEqualToAttribute("String1"));
++++++++Console.WriteLine(IsEqualToAttribute("blah"));
++++++++Console.ReadKey();
++++}

++++public+static+bool+IsEqualToAttribute(string+mystring)
++++{
++++++++//Let's+get+all+the+properties+from+Usage
++++++++PropertyInfo[]+props+=+typeof(Usage).GetProperties();
++++++++foreach+(var+prop+in+props)
++++++++{
++++++++++++//Let's+make+sure+we+have+the+right+property
++++++++++++if+(prop.Name+==+"SomeProperty")
++++++++++++{
++++++++++++++++//Get+the+attributes+from+the+property
++++++++++++++++var+attrs+=+prop.GetCustomAttributes();

++++++++++++++++//Select+just+the+attribute+named+"MyAtt"
++++++++++++++++var+attr+=+attrs.SingleOrDefault(x+=>+x.GetType().Name+==+"MyAtt");
++++++++++++++++MyAtt+myAttribute+=+attr+as+MyAtt;+//Just+casting+to+the+correct+type
++++++++++++++++if+(myAttribute.name+==+mystring)+//Compare+the+strings
++++++++++++++++++++return+true;
++++++++++++++++if+(myAttribute.anotherstring+==+mystring)+//Compare+the+strings
++++++++++++++++++++return+true;
++++++++++++}
++++++++}

++++++++return+false;
++++}
}|code-block|syntax|javascript|5ai1f|正如您所看到的，我们使用反射从属性中获取属性，然后只比较属性。|avnup|更多信息可在此处找到：https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/concepts/attributes/accessing-attributes-by-using-reflection|offset|length|3a05p|就获取构造函数属性而言，如下所示|9b6cg|typeof(MyAtt).GetConstructor().GetParameters()|8i05u|将检索构造函数的参数详细信息。|f52k5|在微软文档中也有关于这方面的信息：https://docs.microsoft.com/en-us/dotnet/api/system.reflection.customattributedata.constructor?view=netframework-4.7.2|eje79^0|0|0|0|B|3H|0|0|0|0|0|H|39|1|0^^$0|$1|$2|3|4|5|6|$7|8]]|9|$2|3|4|5|6|$7|A]]]|B|@$C|D|E|F|2|G|H|14|I|@]|J|@]|6|$]]|$C|K|E|L|2|M|H|15|I|@]|J|@]|6|$N|O]]|$C|P|E|Q|2|G|H|16|I|@]|J|@]|6|$]]|$C|R|E|S|2|G|H|17|I|@]|J|@$T|18|U|19|C|1A]]|6|$]]|$C|V|E|W|2|G|H|1B|I|@]|J|@]|6|$]]|$C|X|E|Y|2|M|H|1C|I|@]|J|@]|6|$N|O]]|$C|Z|E|10|2|G|H|1D|I|@]|J|@]|6|$]]|$C|11|E|12|2|G|H|1E|I|@]|J|@$T|1F|U|1G|C|1H]]|6|$]]|$C|13|E|-4|2|G|H|1I|I|@]|J|@]|6|$]]]]

This primarily depends on what attribute you're looking at and how it's coded. See the code below as an example on how to do what you're asking.

<pre><code>//The attribute we're looking at
public class MyAtt : System.Attribute
{
 public string name;
 public string anotherstring;

 public MyAtt(string name, string anotherstring)
 {
 this.name = name;
 this.anotherstring = anotherstring;
 }
}

public static class Usage
{
 [MyAtt("String1", "String2")] //Using the attribute
 public static string SomeProperty = "String1";
}

public static class Program
{
 public static void Main()
 {
 Console.WriteLine(IsEqualToAttribute("String1"));
 Console.WriteLine(IsEqualToAttribute("blah"));
 Console.ReadKey();
 }

 public static bool IsEqualToAttribute(string mystring)
 {
 //Let's get all the properties from Usage
 PropertyInfo[] props = typeof(Usage).GetProperties();
 foreach (var prop in props)
 {
 //Let's make sure we have the right property
 if (prop.Name == "SomeProperty")
 {
 //Get the attributes from the property
 var attrs = prop.GetCustomAttributes();

 //Select just the attribute named "MyAtt"
 var attr = attrs.SingleOrDefault(x =&gt; x.GetType().Name == "MyAtt");
 MyAtt myAttribute = attr as MyAtt; //Just casting to the correct type
 if (myAttribute.name == mystring) //Compare the strings
 return true;
 if (myAttribute.anotherstring == mystring) //Compare the strings
 return true;
 }
 }

 return false;
 }
}
</code></pre>

As you can see we get the attribute off the property using reflection and then just compare the properties. 

More info can be found here: 
<a href="https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/concepts/attributes/accessing-attributes-by-using-reflection" rel="nofollow noreferrer">https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/concepts/attributes/accessing-attributes-by-using-reflection</a>

As far as getting the constructor properties something along the lines of

<pre><code>typeof(MyAtt).GetConstructor().GetParameters()
</code></pre>

Would retrieve the parameter details for the constructor.

There is also info on this in the Microsoft Docs: <a href="https://docs.microsoft.com/en-us/dotnet/api/system.reflection.customattributedata.constructor?view=netframework-4.7.2" rel="nofollow noreferrer">https://docs.microsoft.com/en-us/dotnet/api/system.reflection.customattributedata.constructor?view=netframework-4.7.2</a>

entityMap|blocks|key|7b1vk|text|这里有一种方法可以做你想要的，但它不是特别可伸缩的，并且需要一堆手动代码才能工作，但可能会让你走上你想要实现的道路。假设我们有一个这样的属性，它的构造函数中有一个字符串数组：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2q4tp|public+class+MyAttrAttribute+:+Attribute
{
++++public+string[]+AllowedValues+{+get;+}
++++public+MyAttrAttribute(params+string[]+values)
++++{
++++++++AllowedValues+=+values;
++++}
}|code-block|syntax|javascript|98s1d|您可以将字段更改为具有支持字段的属性。这允许您覆盖set方法并在其中执行检查：|offset|length|style|CODE|34ir5|private+string+_testArg;

[MyAttr("TestArg1",+"TestArg2")]+//check+that+some+string+equals+TestArg1/TestArg2
public+string+TestArg
{
++++get+=>+_testArg;

++++set
++++{
++++++++var+allowedValues+=+this.GetType()+//Get+the+type+of+'this'
++++++++++++.GetProperty(nameof(TestArg))+//+Get+this+property
++++++++++++.GetCustomAttribute<MyAttrAttribute>()+//+Get+the+attribute
++++++++++++.AllowedValues;+//Get+the+allowed+values+specified+in+the+attribute

++++++++if(!allowedValues.Contains(value))
++++++++{
++++++++++++throw+new+ArgumentOutOfRangeException(nameof(value),+
++++++++++++++++$"The+value+'{value}'+is+not+allowed");
++++++++}
++++++++_testArg+=+value;
++++}
}|7hbbh|说了这么多，我坚信有更好的方法来实现你所要求的。例如，如果您只能使用最小的值集，那么enum几乎肯定是比string更好的选择。|cr5d9^0|0|0|P|3|0|0|16|4|0^^$0|$]|1|@$2|3|4|5|6|7|8|S|9|@]|A|@]|B|$]]|$2|C|4|D|6|E|8|T|9|@]|A|@]|B|$F|G]]|$2|H|4|I|6|7|8|U|9|@$J|V|K|W|L|M]]|A|@]|B|$]]|$2|N|4|O|6|E|8|X|9|@]|A|@]|B|$F|G]]|$2|P|4|Q|6|7|8|Y|9|@$J|Z|K|10|L|M]]|A|@]|B|$]]|$2|R|4|-4|6|7|8|11|9|@]|A|@]|B|$]]]]

Here is one way to do what you are asking for, but it's not particularly scaleable and requires a bunch of manual code to get working but may get you on the road to what you are trying to achieve. Assuming we have an attribute something like this that takes a string array in it's constructor:

<pre><code>public class MyAttrAttribute : Attribute
{
 public string[] AllowedValues { get; }
 public MyAttrAttribute(params string[] values)
 {
 AllowedValues = values;
 }
}
</code></pre>

You can change your field to be a property with a backing field. This allows you to override the <code>set</code> method and do your checking in there:

<pre><code>private string _testArg;

[MyAttr("TestArg1", "TestArg2")] //check that some string equals TestArg1/TestArg2
public string TestArg
{
 get =&gt; _testArg;

 set
 {
 var allowedValues = this.GetType() //Get the type of 'this'
 .GetProperty(nameof(TestArg)) // Get this property
 .GetCustomAttribute&lt;MyAttrAttribute&gt;() // Get the attribute
 .AllowedValues; //Get the allowed values specified in the attribute

 if(!allowedValues.Contains(value))
 {
 throw new ArgumentOutOfRangeException(nameof(value), 
 $"The value '{value}' is not allowed");
 }
 _testArg = value;
 }
}
</code></pre>

Having said all of this, I firmly believe that there is a better way to achieve what you are asking. For example, if you are restricted to a minimal set of values, then an <code>enum</code> would almost certainly be a better option than a string.

How can i check that some string is equal to the "constructor" arguments of an attribute?
And how to get all constructor values (TestArg1, TestArg2)?

<pre><code>struct MyData
{
 [MyAttr("TestArg1", "TestArg2")] //check that some string equals TestArg1/TestArg2
 public string TestArg;
}
</code></pre>

C# Attribute check is an value equals the constructor argument and get constructor values

如何检查某个字符串是否等于属性的“构造函数”参数？如何获取所有的构造器值(TestArg1，TestArg2)？<code>A0</code>

问C#属性检查是一个等于构造函数参数和获取构造函数值的值
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