Operators in .NET

[stovellp]

Ok this is an easy one.

 

How do I create a custom assignment operator for my own classes in C#? The types to be assigned to my class are DataReader classes (for SQL and Access) so my class may act as a wrapper for them.

 

Something like

class Myclass
{
 operator = (accessdatareader adr)
 {
   mydatareader = adr;
 }
} 

[PlausiblyDamp]

In C# the assignment operator (=) cannot be overloaded. What are you trying to do? Is your class encapsulating the DataReaders and adding extra functionality?

[stovellp]

Yep. I want to be able to do:

 

MyResultType result = sqlDataReader;

 

or

 

result = oledbDataReader;

 

or result = myresulttype;

[PlausiblyDamp]

How about using the IDataAdapter interface?

IDataAdapter result = sqlDataReader;
//or
result = oleDbDataReader;

[stovellp]

Because I have a wrapper to make it easier to use the Data Adapters, and I also want to extend it into XML, my own config files, MySQL and other data sources, so if I used IDataAdapter I would be more limited.

[PlausiblyDamp]

Could you not make your class implement IDataAdapter instead then?

[stovellp]

Lol, currently I'm just using functions such as AssignMSSQL(sqlDataAdapter);, I'll just keep it like that.

 

Is there a reason why the C# creators chose not to allow assignment overloading? I absolutely love C#, it kicked C++ off my favorite language shelf after only a month of using it, so I'm sure they have a valid reason for doing this :)

[Arch4ngel]

I don't know why they can't but...

For your problem... maybe you could use a property to get the result ?

No ? Don't have to overload the assignement operator and got the job done.

Edited March 25, 2004 by Arch4ngel

[Nerseus]

You can overload assignment though it's syntax isn't quite the same - you don't overload the "=" operator.

 

Here's a sample for how to do it:

public static implicit operator MyResultType(DataReader op)
{
return new MyResultType(op);
}

 

This allows assigning a variable of tyep MyResultType to a variable of type DataReader. In my sample, I assume you have a constructor on

MyResultType that takes a DataReader and does something useful with it.

 

You can replace implicit with explicit if you need to. Check the help on more info.

 

-Nerseus