Csharp/C Sharp by API/System/AttributeTargets

AttributeTargets.All

<source lang="csharp"> using System; using System.Reflection;

[AttributeUsage(AttributeTargets.All)] class RemarkAttribute : Attribute {

 string remarkValue; 

 public RemarkAttribute(string comment) { 
   remarkValue = comment; 
 } 

 public string remark { 
   get { 
     return remarkValue; 
   } 
 } 

}

[RemarkAttribute("This class uses an attribute.")] class UseAttrib {

 // ... 

}

public class AttribDemo {

 public static void Main() {  
   Type t = typeof(UseAttrib); 

   Console.Write("Attributes in " + t.Name + ": "); 

   object[] attribs = t.GetCustomAttributes(false);  
   foreach(object o in attribs) { 
     Console.WriteLine(o); 
   } 

   Console.Write("Remark: "); 

   // Retrieve the RemarkAttribute. 
   Type tRemAtt = typeof(RemarkAttribute); 
   RemarkAttribute ra = (RemarkAttribute) 
         Attribute.GetCustomAttribute(t, tRemAtt); 


   Console.WriteLine(ra.remark); 
 }  

}

</source>

AttributeTargets.Class

<source lang="csharp"> using System; using System.Reflection; [AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct)] public class Creator : System.Attribute {

   public Creator(string name, string date) {
       this.name = name;
       this.date = date;
       version = 0.1;
   }
   string date;
   string name;
   public double version;

} [Creator("T", "05/01/2001", version = 1.1)] class MainClass {

   static public void Main(String[] args) {
       for (int i = 0; i < args.Length; ++i)
           System.Console.WriteLine("Args[{0}] = {1}", i, args[i]);
   }

}

</source>

AttributeTargets.Struct

<source lang="csharp"> using System; [AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct,Inherited = false)] public class ClassVersionAttribute : System.Attribute {

   public ClassVersionAttribute(string target) : this(target, target) {
   }
   public ClassVersionAttribute(string target,string current) {
       m_TargetVersion = target;
       m_CurrentVersion = current;
   }
   private bool m_UseCurrentVersion = false;
   public bool UseCurrentVersion {
       set {
           if (m_TargetVersion != m_CurrentVersion) {
               m_UseCurrentVersion = value;
           }
       }
       get {
           return m_UseCurrentVersion;
       }
   }
   private string m_CurrentName;
   public string CurrentName {
       set {
           m_CurrentName = value;
       }
       get {
           return m_CurrentName;
       }
   }
   private string m_TargetVersion;
   public string TargetVersion {
       get {
           return m_TargetVersion;
       }
   }
   private string m_CurrentVersion;
   public string CurrentVersion {
       get {
           return m_CurrentVersion;
       }
   }

}

</source>