Code Snippets

Generating a Property Stub | Get Ready For C# 4.0

noreply@blogger.com (Tarek N. Elsamni) — Sun, 25 Apr 2010 02:46:00 +0200

If code references an undefined property, click Generate property stub. The property stub is generated in the appropriate class. The property’s return type is determined from the context.

For example, assume that you generate the InstanceProperty property from the statement in the following code.

When you generate the property, the following stub is created in the Customer class.

If a property is invoked on a type and not an instance, the generated stub will be a static property (C#) or a shared property (Visual Basic).

For example, imagine that you generate a property from the following statement (assuming that Customer is a class name).

When you generate the property, the following stub is created in the Customer class.

If a property is invoked without a qualification (referring to a member of the current type), the generated stub is static if the property is called from a static method. Otherwise, it is an instance property.

For example, assume that you generate a property from the following statement.

When you generate the property, the following stub is created in the current class.

Indexed properties | Get Ready For C# 4.0

noreply@blogger.com (Tarek N. Elsamni) — Sat, 24 Apr 2010 12:35:00 +0200

Many COM APIs expose “indexed properties” which are essentially properties with parameters. C# will not allow you to declare indexed properties, but to the extent that non-C# APIs expose them, will now allow you to access these using element access syntax. So instead of

You can now write the more intuitive

Dynamic import | Get Ready For C# 4.0

noreply@blogger.com (Tarek N. Elsamni) — Sat, 24 Apr 2010 12:33:00 +0200

Many COM methods accept and return “variant” types, which are represented in the PIAs as object. In the vast majority of cases, a programmer calling these methods already knows the static type of a returned object from context, but explicitly has to perform a cast on the returned value to make use of that knowledge. These casts are so common that they constitute a major nuisance.
In order to facilitate a smoother experience, if you choose to import these COM APIs with PIA-embedding, variants are instead represented using the type dynamic. In other words, from your point of view, COM signatures now have occurrences of dynamic instead of object in them.
This means that you can easily access members directly off a returned object, or you can assign it to a strongly typed local variable without having to cast. To illustrate, you can now say

instead of

and

instead of

Optional (or Default) Parameters | Get Ready For C# 4.0

noreply@blogger.com (Tarek N. Elsamni) — Sat, 24 Apr 2010 01:19:00 +0200

I see that people have been asking for this feature since C# 1.0. Three versions later, it’s finally here.

Now you can assign a default value to a parameter right within the method declaration. The user of the method can either pass a value or simply skip the argument. In the latter case, the default value is passed to the method.

Method declaration:

Method calls:

Dynamic Keyword | Get Ready For C# 4.0

noreply@blogger.com (Tarek N. Elsamni) — Sat, 24 Apr 2010 01:14:00 +0200

The dynamic keyword is a key feature of this release. It closes the gap between dynamic and statically-typed languages. Now you can create dynamic objects and let their types be determined at run time. With the addition of the System.Dynamic namespace, you can create expandable objects and advanced class wrappers, and you can provide interoperability between different languages, including dynamic ones. Here is one quick example:

More Complicated Example:

Simple WCF chat application with database (LINQ)

noreply@blogger.com (Tarek N. Elsamni) — Thu, 14 Jan 2010 14:47:00 +0200

This project will be consisted of a WCF service (ISERVICE [Interface] & SERVICE [C# code to implement the interface]), Server Application which will use the WCF service and finally the client(Windows Form).

In our SERVICE we will have 2 Interfaces:

The first Interface will be Implemented in Service.cs as the WCF service to make Server side operations like:
Register, Login, logout and Add Friend.

for Example:

Ths second Interface will be Implemented in the client form as a callback mehods which will be used by server to make changes in form's data to represent changes in server side.

for example:

This Application Full Source can be downloaded from this link:
Download

To Test this application you need first to import application MSSQL named: ChatDB.mdf in the attached file and run the server project then run the client to test it.

How to hide characters from being displayed on screen as they are keyed in?

noreply@blogger.com (Tarek N. Elsamni) — Tue, 12 Jan 2010 11:00:00 +0200

As has been mentioned, standard C keyboard input routines (getc, fgets, scanf, etc.) buffer the input until you press "Enter" --- and they echo each character as its key is pressed.

Old-style DOS functions like getch() are still available in certain Windows command-line application compilers (such as Borland C, for example). getch() returns the character to the calling program but doesn't echo it to the screen.

Here is a routine that I picked up somewhere some time ago (sorry, I didn't record the source, but I am quite sure I didn't delete any copyright notice). If it turns out that it is copyrighted or patented or something: let me know.

I compiled and executed it on my Linux system, and also on my windows system (using CYGWIN gcc). Output looks the same.

Here's the function, called linux_getch():

Here's a test program for linux_getch():

Upload a file using c# as client to a PHP server

noreply@blogger.com (Tarek N. Elsamni) — Mon, 11 Jan 2010 23:46:00 +0200

We'll call the PHP script "upload.php", this is what it should contain:

and this is the C# code:

PHP random password generator

noreply@blogger.com (Tarek N. Elsamni) — Mon, 11 Jan 2010 23:31:00 +0200

PHP password generator is a complete, working random password generation function for PHP. It allows the developer to customize the password: set its length and strength. Just include this function anywhere in your code and then use it.

2ADQZNUV2VG8

PHP Class to Generate/Restore backup from/to MYSQL database

noreply@blogger.com (Tarek N. Elsamni) — Mon, 11 Jan 2010 19:23:00 +0200

This PHP class will help you to take a backup from your MYSQL database as it will generate .gz file to be downloaded or stored on a specific path.

First you need to include the PHP class to use it:

Then you have 3 different ways to take the backup:

To restore a MYSQL database backup include restore class:

Then start restoring process:

This class & more examples can be downloaded from this link: Download