By the help of David hayden article http://davidhayden.com/blog/dave/archive/2006/03/07/2876.aspx
I make an attribute class TableAttribute ,KeyAttribute and two of my classes
that is
[
AttributeUsage(AttributeTargets.Class, AllowMultiple = false)] public class TableAttribute : System.Attribute{
private string _name; public string Name{
get{
return _name;}
set{
_name =
value;}
}
public TableAttribute(string name){
_name = name;
}
}
-----------------------------------------------------------------------------------------------------------------------------------
[
AttributeUsage(AttributeTargets.Property, AllowMultiple = false)]public
class KeyAttribute : System.Attribute{
public KeyAttribute(){
}
private string _name; public string Name{
get{
return _name;}
set{
_name =
value;}
}
private bool _isIdentity; public bool IsIdentity{
get{
return _isIdentity;}
set{
_isIdentity =
value;}
}
}
------------------------------------------------------------------------------------------------------------------------------------
[
Table("Employee")]public
class Employee{
private int id; private string employeeName;[
Key(Name = "employee_id", IsIdentity = true)] public int EmployeeID{
get{
return id;}
set{
id =
value;}
}
[
Key(Name = "employee_name", IsIdentity = false)] public string EmployeeName{
get{
return employeeName;}
set{
employeeName =
value;}
}
}
-----------------------------------------------------------------------------------------------------------------------------
[
Table("Customer")]public
class Customer{
private int id; private string customerName;[
Key(Name = "customer_id", IsIdentity = true)] public int CustomerID{
get{
return id;}
set{
id =
value;}
}
[
Key(Name = "customer_name", IsIdentity = false)] public string CustomerName{
get{
return customerName;}
set{
customerName =
value;}
}
// Anything...}
---------------------------------------
Now how can I retrieve the value of the attribute of properties (that is employee_name,employee_id)
I pass Employee in this method
private void PrintProperties(Type type){
PropertyInfo[] properties = type.GetProperties(); foreach (PropertyInfo p in properties){
//Response.Write(@"[" + keys.GetValue(0).ToString() + @"]<br />"); //here i want's to get attribute name that is employee_nameResponse.Write(
@"Name = [" + p.Name.ToString() + @"] Value=[]<br />"); //here i get EmployeeName}
}
Getting Name of particular attribute of a property by using reflection.
Markus H
VBFan
Each PropertyInfo have GetCustomAttributes(), inside them you can search your FieldAttribute.
Timothy P
If I understand the question correctly, you do something like this
string keyName = ((KeyAttribute)Attribute.GetCustomAttribute(p, typeof(KeyAttribute))).Name;
ShawnReed
One more rock into .NET architects - two ways to get same functionality.
I would prefer to have same functionality inside single place. Now I understand why reading names of the upcoming Vista classes took so long time...
Alec Yu
Right, but if you take a closer look at my code you'll see that I used GetCustomAttribute (which returns a single object), not GetCustomAttributes.
Prasad Honrao
foreach (PropertyInfo p in properties)
{
// Find the KeyAttributes on the current property.
// Also search this member's chain to find the attributes.
object[] attributes = p.GetCustomAttributes( typeof(KeyAttribute), true );
// If there where attributes found, print them.
if( attributes != null && attributes.Count != 0 )
{
foreach( KeyAttribute key in attributes )
{
Console.WriteLine( "Property name = '{0}', Keyname = '{1}'", p.Name, key.Name );
}
}
else
{
// the current property didn't have KeyAttributes.
Console.WriteLine( "Property {0} has not KeyAttributes.", p.Name );
}
}
Suresh
a little more laconic version:
foreach(KeyAttribute key in p.GetCustomAttributes(typeof(KeyAttribute), true))
{
}
GetCustomAttributes() will always return an array, empty if no attributes found.