Development Romance

watiN: How to automate your browser to do forum posts for you

2010-03-15T12:05:54Z

In this post, we are going to see how to automate our browser to do forum posts for us. The tool that is used for browser automation is called watiN. Download the package, unzip it, put it in the program files folder and we are ready to create our first automation program.

Create a new WPF project (as you can see, you don’t need any special project template to do your job):

Add the following XAML code in your window:

Now, your window should look like this:

It’s time to use watiN, thankfully, the only thing we need to do is add a .dll reference. Right click on your project ---> add reference ---> navigate to the folder where you put the watiN folder, open it, open the bin folder and choose the WatiN.Core.dll library:

Now it’s time for some real action, add a using of the WatiN.Core namespace, add a private variable just like the following one:

Go to the SubmitButton_Click event and lets get started to use this fine tool:

In this part we create a browser instance and command it to navigate to a specific url. The IE class handles an instance of the Internet Explorer browser. For more information about the watiN classes, have a look at the watiN documentation.

Now, we need to know the name of the html input controls that form the html form of the login action. A very good tool for such purposes is the firebug plugin for firefox and the developer toolbar for Internet Explorer.

The image above is an example of the firebug plugin with which we find the name attribute of the username text input. Using such tools we may now write the following code:

We search for a username text input, if it’s found, then we must login, else ti means tha we are already logged in. We type our username and password in the appropriate text inputs, we click on the checkbox in order to be remebered and finally we click on the “Log in” button to log in. If the username text input is found again, it means tha the credentials we provided are invalid.

Finally, we add the following code in order to make a new post:

We find the text input for the quick reply and click on the button to submit our post.

Lets see an example:

As you can see, the post was made successfully.

You can download the program here.

I hope you enjoy it !!

Getting started with WPF validation

2010-02-20T20:08:26Z

In this post we are going to see how we can validate input controls in WPF

1. Gettting started

Create a new WPF application and add the following controls:

It should look like this:

Finally, change the code behind so that it looks like this:

2. Create the validation rule

This form is valid only if the text box is not empty, so we need a rule that validates the text box. Create a new class and name it RequiredValidator:

Inherits the ValidationRule class and overrides the Validate function. This function is responsible for validation of any input. If the text box is empty, it returns a new ValidationResult object which indicates that input is invalid, else, it returns the ValidationResult object which indicates that input is valid.

Now we must add this class to the previous window like this:

Change text box’s properties so that it looks like this:

Now the text box is bound to a property named Text which resides in our Window1 class, when its text is changed, ti automatically updates the value of the property it’s bound to. As you can see, we have added the RequiredValidator class in the validation rules of this binding. Build and run and you should see something lie this:

The red border indicates that input is invalid. If you type anything and after that press the button, the red border is gone.

3. Change the error template

As we saw earlier, the default error template is the red border around the text box, but this is not that useful, so lets see how to create our own error template.

We are going to change the style of this text box and add a new ControlTemplate for the ErrorTemplate. Add the following in the window resources (Window.Resources):

Now, it should look like this:

4. Disable button if input is invalid

Make the following changes in the xaml code:

Handle the TextChanged event of the text box and disable the button.

In the TextChanged event handler:

This means that if input is invalid, the button is disabled.

Creating applications with plug-in support

2010-01-23T14:32:32Z

In order to let your application to have plug-in support, you need to follow these steps:

Create an interface that every plug-in will implement
Choose a place in which the plug-ins will reside
Make your application find those plug-ins and invoke their actions

Lets see an example, in which we have a window that contains a TextBox and a Button and when the button is pressed, all plug-ins are invoked:

You may press the button as many times as you like, but nothing is going to happen. It may be an unuseful application, but we are going to let users add their own functionality with plug-ins.

Step 1: Create an interface that every plug-in will implement

In order to recognize our plug-ins, they need to have a specific form (implement an interface). Create a new class library project and create the following interface:

This is the interface that every plug-in is going to implement. As you can see, there is also another class: The PluginContext class. This class is, actually, the parameters passed from the main application. In this example, it is like this:

It only passes the text of the textbox.

Build the project and now that the library is ready, add a reference to it in the main application.

Lets create our first plug-in now:

Create a new class library project, add a reference to the library that contains the plug-ins’ interface and create a class like the following one:

The purpose of this plug-in is to keep only the english letters in the textbox. Build it and we are ready to move on.

Step 2: Choose a place in which the plug-ins will reside

They may reside anywhere you like. In this example, we are going to create a directory named Plugins:

Every plug-in we create will be put inside this directory. Lets add the plug-in we created earlier:

Step 3: Make your application find those plug-ins and invoke their actions

We are ready for the final step, create a handler for button’s click event and add the following code:

It check the Plugins directory for files with a .dll extension and if finds one, load the assembly, checks all its types and if it finds a type that implements the IPlugin interface, invokes its action and saves the results in the textbox.

Here is the code of this example, i hope you like it and, why not, create new plug-ins for this example !!

Beginning with windows mobile SDK

2010-01-22T20:40:39Z

Recently, i purchased a samsung omnia in a very good price and decided to create a small application for it. All i needed was the windows mobile SDK 6.0 professional and windows Mobile 6.5 Developer Tookit. Thankfully, i finished my application and decided to make this blog post in order to write a small guide into beginning using the mobile SDK with smartphone’s special features, like sending sms messages, making phone calls, detecting sms messages, doing operations with your contacts, pictures etc, using the camera.

1st part: Windows Forms

The platform in which you develop your applications, is a subset of the windows forms. You can download my application here, so that you can have a look at the way a windows mobile application is made. It’s a small program that groups your contacts and lets you send an sms message to all members of a group (it’s temporary in greek).

2nd part: smartphone special features

Here are examples of some special features:

Send sms message:

Make a phone call:

Detect sms messages:

Choosing contact:

Choosing picture:

Using camera:

I hope you like it….!!!

CSS Tips – Tip 2 – Stretch background image

2010-01-03T23:53:00Z

Today is a special day, do you know why ? Because i am finally able to put my favorite band’s album cover as a background image on my web site and let it stretch so that it covers the whole page without any loops. Do you want to know how ? Lets have a look together.

In CSS 3, there is a straight way to stretch a background image, but in CSS 2, there is no straight way, so we are going to use the following trick:

put an image in your page via the <img> tag
position it at the top left corner via CSS
make it use all of the available page height and width via CSS
make it be under every element on your page via CSS

Here are the answers:

<img src=”image url” id=”background_image” />
body, html { width: 100%; height: 100%; } #background_image { position: fixed; top: 0px; left: 0px; }
body, html { width: 100%; height: 100%; } #background_image { position: fixed; top: 0px; left: 0px; width: 100%; height: 100%; }
body, html { width: 100%; height: 100%; } #background_image { position: fixed; top: 0px; left: 0px; width: 100%; height: 100%; z-index: –1; }

Hope you enjoy it !!

: strange extra white space at the beginning of page

2009-12-30T21:15:26Z

Well, recently i took my first steps with php, created a header, a footer, saved them as UTF-8 pages, and included them in each page. By the time i tested my web application for the first time, i recognized a strange extra white space at the beginning of each page, just like the following:

I began checking my css rules and my javascript scripts, but none of these had anything to do with this feature. My next step was to search the internet for a similar case. What i found is that if you choose to save your pages as UTF-8, a special signature is also included at the beginning of the file, indicating that it is a UTF-8 file. Hopefully, we can remove that signature without problem, but it isn’t recognised by every editor, only the “low-level” ones are capable of showing the signature. I opened my file with the edit command of the DOS command prompt:

As you can see, a chunk of bytes is included at the beginning of the file, i deleted it, saved and all my problems were solved.

Now my page looks like this:

I hope this helps. Have a happy new year’s eve !!

Unit Testing

2009-12-24T17:52:00Z

One of the worst things a developer is anxious for is being sure that their application is fully correct. There are many ways to test your applications

Using messages to test if your procedures are correct
Setting breakpoints in order to debug your application
e.t.c.

Here comes the unit testing feature. Unit testing is not just another way to debug your application, but a way to put some tests to it in order to secure that it is correct if they are passed.

Lets have a look at how we can set such tests:

1. Assume that we have a project with the following file:

and we want to check if it is totally correct. Add a new project with the following template:

2. Add existing file --> the above file. The test project should look like this:

3. Open the UnitTest1.cs file and have a look at the TestMethod1 function. As you can see, it has a TestMethod Attribute, this assumes that this function is used for testing purposes. You may create any function you want to test your application but it must contain a TestMethod Attribute. Lets put some testing functions like the following ones:

4. Run the test project and have a look at the tab which is shown. It Indicates which tests are passed and which not:

I hope you find it useful. Merry Christmas and happy testing !!

IKVM: Write Java with C#

2009-12-11T19:59:09Z

Recently, i had a project in which i had to use weka for data mining, but the only libraries i found can only be used with Java, so i wondered if i could use C# instead of Java. I began searching for such a tool and found the IKVM (http://www.ikvm.net/).

Using the IKVM, you may use Java libraries straight from C# code.

Lets have a look at the following example:

1. Download the IKVM from http://www.ikvm.net/download.html.

2. Extract the files included, create a new project and add a reference to the following .dll files from the those extracted:

3. Add the following code and run it to see the results:

4. IKVM is also capable of converting .jar files into .dll libraries. In the extracted files, search for an executable named ikvmc.exe. Open a command prompt and run this executable giving the path to the .jar file as the first argument.

If the .jar file contains a main method, it produces a .exe file instead.

WPF και Facebook + Twitter training για τους συμμετέχοντες του Imagine Cup 2010

2009-11-25T08:45:00Z

Την περασμένη Παρασκευή έλαβε χώρα το training για το Windows Presentation Foundation (WPF) και χθες το training για τα Facebook και Twitter APIs. Καλή συνέχεια στους συμμετέχοντες, happy coding and may the force be with you !!

Τα links με το υλικό του training:

WPF training

Facebook + Twitter APIs training

CSS Tips - Tip 1: IE specific css

2009-11-21T17:08:00Z

Have you ever found yourself in a situation in which you want to add a css style only for IE ? If yes, today is your lucky day. Have a look at this example:

#myDiv { padding-top: 10px; height: 40px; } /* css style for all browsers */

html>body #myDiv { padding-top: 10px; height: 50px; } /* css style for all browsers except IE */

Add both of them in your css file and see the results.

SolidTube: A new Youtube desktop client

2009-11-15T11:19:15Z

Recently, i started searching for a new API to play with, hopefully i found the Youtube REST API, so i decided to create a desktop client with it.

Here’s how it works:

You enter a title to search:

Click on the title of the video you want:

And voila, you may watch it from your desktop without having to open any browser:

I hope you like it and i’d be grateful to see your comments. Have a nice time !!

download

WPF Youtube player user control

2009-11-08T19:30:54Z

Today, i had a fine idea to create a Youtube desktop client, but first, i had to create a user control in order to embed youtube video player in a window.

An example:

You can download this user control from codeplex (source code available).

Download file using ASP.NET

2009-11-04T23:22:00Z

Well, ASP.NET gives us an upload control, but what happens when we like to download a file ? One way is to add an anchor link (<a>…</a>) pointing to a file, in this case, when users click on the link, are able to download the specified file. However, what happens when we add a button that when clicked, user downloads a file ?

The follwing code lets us download a file using the Response object:

WPF Toolkit Tutorial – Part 2

2009-10-26T23:30:00Z

In the last episode , we saw what we can do with WPF toolkit’s charts, today, we are going to see the last masterpiece of this tutorial: The DataGrid.

If you have worked previously with windows forms, you certainly know the DataGrid, if not, then i’ll make a simple explanation: It’s a control which can visualize, in a grid, the contents of a DataTable, whose content may vary from simple data to database data.

The following example shows how to visualize northwind database’s categories using the DataGrid:

Create a new WPF project with visual studio.

Have a look at the toolbox:

Now, add a DataGrid to your window:

You must bind your DataGrid with its data. You can do it like this:

You are now ready to watch your progress:

You may add a new row:

You may delete (by pressing “delete”) or edit a row (by double clicking on it).

It contains a lot more features that await you to discover. Keep coding and having fun !!

Visual Studio Setup Project: How to add Uninstall option

2009-10-25T16:08:00Z

I suppose you have made, at least once, a setup project to deploy your application, using visual studio’s special setup project template. As you already know, every program you install in your computer has an option to let you uninstall it. But, visual studio’s setup project doesn’t have such an option, so we’re going to see a simple way on how to add it.

Click on the setup project:

Click on the properties tab and copy the product code:

Now, create a new file named Uninstall.bat with the following content:

@echo off

msiexec /x “product code”

Where “product code” is the product code you copied earlier. For example:

After that, add the Uninstall.bat file in the application folder.

You can also create a shortcut for the Uninstall.bat file in user’s desktop and user’s programs menu folders.

Finally, build the setup project and your application is ready to be installed and uninstalled later :p !!