Csharp/C Sharp by API/System/AttributeTargets

AttributeTargets.All

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); 
  }  
}

AttributeTargets.Class

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]);
    }
}

AttributeTargets.Struct

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;
        }
    }
}