Hi, I am using C# to program a web application. Is it possible to create user-defined objects just like JAVA programming? For example, I have a class called HouseDB.cs, and a code-behind class called House.aspx.cs. I would like the HouseDB.cs acting as a simple database manager, ie,an entity class accessing database. Is it ok to put following code in House.aspx.cs?


House housesearch = new House()

then use housesearch.blahblah
to invoke House's methods.


I tried, but failed. Have no idea what has gone wrong...

Hello for sure, C# is an object oriented programming language. Which means that it follows OOP ideas. Maybe you have to have a look at :

C# OOP

regards

---

Bilal Hadiar, MCP, MCTS, MCPD, MCT
Microsoft MVP - Telerik MVP

Yep... but the error said cant find data type "House". I know in JAVA, as long as u put class files in the same directory, the compiler will look for them automatically. But this seems not the case for C#. I then tried adding a "using" statement, something like:

using [namespace of House].House

But error remains, saying cant find [namespaceof House].House.

What should i do to make it find my House class? have I done anything wrong?

Thanks!

Another fantastic book is C# Class Design Handbook : Coding Effective Classes .. i learned a lot from this book

Yes, it is possible.

You have to add a reference to the house class to your aspx project (by rightclicking on it).

What's your error message?

Jos

right, in my control class, lets call it ControlObj.cs, i have:

+++++++++++++++++
using DataLayer;

namespace ControlLayer
{
pulic class ControlObj
{
private DataObj mydata;
public ControlObj()
{
mydata = new DataObj()
}
......
}
}
+++++++++++++++++

then in my data entity class, lets call it DataOjb.cs, I have:

+++++++++++++++++
namespace DataLayer
{
using System;
using System.Data;
using System.Data.SqlClient;

public class DataObj
{
private String conn;

public DataObj()
{
conn = null;
}
}
}
++++++++++++++++++

But, every time the runtime complains "CS0246: cant find datatype or namespace "DataLayer". Error line: using DataLayer;" .(I am using Chinese version, but thats what the error means.)

I am completely lost here! This is a very simple example of 3-tier structure, which I copied with little change from the tutorial. But it just did not work! Please, can anyone help? I ve totally no clue and I am nuts.......

Any idea are appreciated!

Thanks very much!

You should compile the project first, create the DLL, and you should work fine, nothing wrong with your code.

regards

---

Bilal Hadiar, MCP, MCTS, MCPD, MCT
Microsoft MVP - Telerik MVP

Did you set a reference to the assembly (DataLayer)??

No, i think no. How should I set a reference to the assembly, please?

What application are you using to create your application?

---

David Wier
MVP/MCP/ASPInsider
ASPNet101.com - where to look first!
iWrite Pro - doc/rtft to HTML/One Click PDF & much more

I am using VS.NET 2003. But strictly speaking not a "project" because I did it by editing aspx and cs files manually and individually.

Also, I am using Mono to compile my code, and got following errors, plus questions:
(DataObj.cs)
Error:
++++++++++
DataObj.cs<17> error CS0246: The namespace System.Data can not be found.<missing assembly reference?>
DataObj.cs<18> error CS0246: The namespace System.Data.SqlClient can not be found.<missing assembly reference?>
Compilation failed: 2 error<s>, 0 warnings
++++++++++

Question:
How to do an assembly reference?
I compiled this using csc.exe, it generated a dll file, but still did not work.

Question 2:
In this case, the BusObj.cs uses DataLayer namespace and creates a DataObj object, so is it true that DataObj.cs must be compiled to make BusObj's compilation successful?

Big Thanks to everyone participates! Ya help are appreciated!
Thanks.