Get field info of base class with reflection

  • Thread starter Thread starter Rotsey
  • Start date Start date
R

Rotsey

Hi,

I have a class that exist in my UI assembly that inherits from a class
in a referenced assembly like this.

class EmployeesDC
{
private string mstrEmployeeNumber;

etc
}

class EmployeesBL : EmployeesDC
{
}

Then in UI Assembly

class Employees : EmployeesBL
{
}

Can someone give me the code so I can get info on the private fields
in EmployeesDC using reflection.

I have googled but I am still not clear how??

thanks
rotsey
 
Rotsey said:
Hi,

I have a class that exist in my UI assembly that inherits from a class
in a referenced assembly like this.

class EmployeesDC
{
private string mstrEmployeeNumber;

etc
}

class EmployeesBL : EmployeesDC
{
}

Then in UI Assembly

class Employees : EmployeesBL
{
}

Can someone give me the code so I can get info on the private fields
in EmployeesDC using reflection.

I have googled but I am still not clear how??

thanks
rotsey
Click to expand...

Hi rotsey,

It's not too complicated, but may I ask what type of information you're
after? If you're after the contents of the field, then is there a reason
why you can't declare it as protected?

If you're after something else, let us know and we'll point you in the right
direction.
 
thanks Tom

All I want is to get the name of all the private fields.

I will then know from the prefix to do something else

rotsey
 
Rotsey said:
thanks Tom

All I want is to get the name of all the private fields.

I will then know from the prefix to do something else

rotsey
Click to expand...

Hi Rotsey,

Cool. Take a look at the following example:

///
using System;
using System.Reflection;

public class A
{
private string pfa_A;
private string pfb_A;
private string pfc_A;
}

public class B : A
{
private string pfa_B;
private string pfb_B;
private string pfc_B;
}

public class C : B
{
public void Foo ()
{
Type t = this.GetType();
BindingFlags bf = BindingFlags.Default;

bf |= BindingFlags.NonPublic;
bf |= BindingFlags.FlattenHierarchy;
bf |= BindingFlags.Instance;

foreach (FieldInfo field in t.GetFields(bf))
{
Console.WriteLine(field);
}
}
}

public class E
{
public static void Main ()
{
C c = new C();
c.Foo();
}
}
///

What's going on here is most interesting in the Foo() method of C. The
inheritance hierarchy is C -> B -> A, and when you call Foo() in C, it will
print out a list of fields it finds.

Modifying bf (the BindingFlags parameter) will help to refine/expand the
search.

The field variable (on each iteration of the foreach statement) will (most
likely) contain everything you need to know about the field.
 
Thank Tom I get it.

One thing though, how would you refactor the code so that
I dont't have to recode foo in all my objects like class C.

rotsey.


"Tom Sp
 
Rotsey said:
Thank Tom I get it.

One thing though, how would you refactor the code so that
I dont't have to recode foo in all my objects like class C.

rotsey.


"Tom Sp
Click to expand...

Hi Rotsey,

There are a couple of approaches to this, the most simple being a static
utility class that exposes a method, taking in the type of the object,
rather than calling GetType in the method.
 
Ok thats what I am doing.

So when I pass the "this" to the static method
do I use "Object" as type

ie
GetFieldtype(this,"EmployeeNumber");

GetFieldtype(Object obj,string fieldname)
{

}

Thats what puzzles me?
 
Tom I have tried using just Foo in each object
but I am not getting any fields returned

Any ideas???


Rotsey said:
Ok thats what I am doing.

So when I pass the "this" to the static method
do I use "Object" as type

ie
GetFieldtype(this,"EmployeeNumber");

GetFieldtype(Object obj,string fieldname)
{

}

Thats what puzzles me?
Click to expand...
 
you gave up on me Tom.

I had to reference the base class directly to get the private fields.

Don't know why your method doesn't work?



Rotsey said:
Tom I have tried using just Foo in each object
but I am not getting any fields returned

Any ideas???
Click to expand...
 
Rotsey said:
you gave up on me Tom.

I had to reference the base class directly to get the private fields.

Don't know why your method doesn't work?
Click to expand...
you gave up on me Tom.
Click to expand...

I may be a student, but I have a job ;-)
I had to reference the base class directly to get the private fields.

Don't know why your method doesn't work?
Click to expand...

Can you post the code you were using?
 
OK thanks for your input.

This is my whoe class in the UI assembly

public class Employees : EmployeesBL, ILoadableData, ILookUpObject

{

public Employees()

{

ConnectString = TBRSettings.Instance.Settings.ConnectionString;

}

public Employees(string connString)

{

ConnectString = connString;

}

public DataSet GetRowFromID(int ID)

{

return GetEmployee(ID);

}

public string GetFieldtype(string fieldname)

{

Type t = this.GetType();

BindingFlags bf = BindingFlags.Default;

bf |= BindingFlags.NonPublic;

bf |= BindingFlags.FlattenHierarchy;

bf |= BindingFlags.Instance;

foreach (FieldInfo field in t..GetFields(bf))

{

if (field.Name.EndsWith(fieldname))

return field.Name.Substring(0, 4);

}

return "";

}

}
 
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