Ruslan Trifonov's blog

I'm looking at me as a regular tech geek spending the most of my personal time to educate my self . I'm reading ,listening , attending ,arguing and blogging in my private personal march to the perfection. Experts, blogs,podcasts, community sites, companies, journalists - all of them are arguing about the best methodology, technology and techniques. All of them are yelling that this or that is the silver bullet for my problems:

"So this week, we're introducing a general-purpose tool-building factory factory factory, so that all of your different tool factory factories can be produced by a single, unified factory. The factory factory factory will produce only the tool factory factories that you actually need, and each of those factory factories will produce a single factory based on your custom tool specifications. The final set of tools that emerge from this process will be the ideal tools for your particular project. You'll have *exactly* the hammer you need, and exactly the right tape measure for your task, all at the press of a button (though you may also have to deploy a few *configuration files* to make it all work according to your expectations)."                                                                                                                                      Why I Hate Frameworks, BenjiSmith

And I'm in the center of all this madness! Alone with my geeky problems waiting to recognize the real panacea for my daily technical problems. I'm into this everlasting quest for the golden hammer for quite a long time and actually this is what thrills me the most in my lonely geeky nights. I don't know actually what I like the most: the moment of feeling, that I found the silver bullet or the next day, when I'm realizing that my geeky quest will continue. We geeks are kind of explorers, arn't we! If we discontinue our exploration activities, we won't be explorers anymore.

I've got this moments, when I feel consistent:  I do not have doubts, I know exactly which tool or technique to use, I feel I'm following up all the new concepts around. And there are short moments, when I feel lost, tired and totally disoriented. This is the payoff for raping my brain with tons of information night after night.

Along with my nightly activities, It is not rare for me to answer to questions from other people around me. Often these are new "kids" in the industry, who think I know the answers of all questions. And here comes my big personal question: TRUE OR FALSE? I am spending a lot of time around my team's young devs and hence I get this kind of questions, when I doubt, what is the right answer. All these guys are trying to get a simple and straightforward answer - the answer of all answers. They ask:

• Is the ORM approach better than the classic Table-driven approach. Why we use ORM, when in on CodeProject somebody said it is a doomed concept.
• Why we have a 3  layers architecture. I've read on Channel 9 that the 4 layers architecture rules.
• Why we are not using WCF, but classic Asp.NET Web Services. They all talk about WCF.
• They said on DotNetRocks.com that  Rubby is so great,  but we are still using C#. Why?
• Why we use Scrum?  My university teacher said that XP is better!
• There is article on MSDN, which says that the future is in the Software Factories and we use some third party Code Gen products. Why's that?
• Shall I use custom Service Locator implementation or using some light container implementation like Castle?
• They said that Personal Social Number should never be a primary key in a table. Why we broke this global rule in our project?

TRUE or FALSE? What to tell these guys, who want to get a simple question to solve their problems. How to give them a simple answer, when there is only a long and complicated one. How to give them this simple answer, when the decisions are bound also to our specific political , business and culture context. They want all-time global and easy answers. This are the moments, when they are learning how to get decisions. Shall I tell them that (often) there is no global and absolute arguments. Shall I tell them that I just don't know for sure , but I think this way it will work just fine . TRUE or FALSE?  Telling TRUE may break their confidence in the industry, in experts  in practices. Telling them FALSE (by hiding some part of the truth) may gave them the wrong idea that this industry is like a religion:that it is all about idols and absolute true.

What do you answer in such situation? TRUE or FALSE?

It is not a rare requirement for a mobile application to provide functionality for capturing a person signature.
So, let's see if we can provide this feature into a mobile application with .NET Compact Framework.
The image bellow outlines the problem that we want to solve:

We have a mobile salesman, who collects customer orders. Our salesman should collect the customer's signatures along with the order's details. Our salesman is carrying a Pocket PC device. We should create
a software solution to allow customer's signature capturing and transmition of the signature over the wire to the office. There we have a Sql Server database to store the signatures into and signatures consuming app. , which may process the stored signatures.

We should solve the following tasks:

1. Capturing a signature from a person from the mobile device
2. Saving the captured signature locally on the mobile device
3. Transmitting the saved signature over the wire and storing it on the server side
4. Consuming the transmitted and saved signature on the server side

Let's try to solve these tasks:

Solving Task 1: Capturing a signature from a person on the mobile device

If a person should place its signature on a Pocket PC, he will probably use the stylus to write his signature on the Pocket PC screen. All we have to do is to capture the on-screen tapings and convert them into a bitmap. We will create a User Control to encapsulate this functionality. The main functionality is divided between the following UserControl event handlers:

• OnMouseDown - here we will "remember" the coordinates of the last on-screen tapping
• OnMouseMove - here we will draw a line from the remembered coordinates to the new(after the mouse move) on-screen mouse coordinates.

Following code example(simplified version)
...
private Bitmap SignatureImage;
private Graphics GraphicsHandle;
privte Point MouseCoords;
....
SignatureImage = new Bitmap(this.Width, this.Height);
GraphicsHandle = Graphics.FromImage(SignatureImage);
...
//remembering the coords of the last on-screen tapping into  MouseCoords member
protected override void OnMouseDown(MouseEventArgs e)
{
  base.OnMouseDown(e);
  MouseCoords.X = e.X;
  MouseCoords.Y = e.Y;
}
//draw a line from the remembered coords to the new on-screen tapping coords
protected override void OnMouseMove(MouseEventArgs e)
{
  base.OnMouseMove(e); 
  GraphicsHandle.DrawLine(SignaturePen, MouseCoords.X, MouseCoords.Y, e.X, e.Y); 
  MouseCoords.X = e.X;
  MouseCoords.Y = e.Y;
} 
//saves the captured bitmap image into a stream
public void Save(Stream stream)
{
   SignatureImage.Save(stream, ImageFormat.Bmp);
}  

Solving Task 2: Saving the captured signature locally on the mobile device

This task is simpler. Let's pretend, we should save the captured image into a local SqlServer Mobile database.
We should have a table containing a field of type image to save the signature into it.

CRATE TABLE CUSTOMERSIGN
{

   customerNo:int not null identity
   sign:image
}

Following the code to save the captured signature:

//our signature control placed into a form
private SignatureControl MySignatureControl;
...
string connectionString =  ...;
...
using (SqlCeConnection connection = new SqlCeConnection(connectionString))
{
  connection.Open();
  SqlCeCommand command = new SqlCeCommand("INSERT INTO CUSTOMERSIGN(sign)VALUES(?)", connection);  

  //getting the captured signature as stream
  MemoryStream signStream = new MemoryStream();
  MySignatureControl.Save(signStream);

  param = new SqlCeParameter("sign", SqlDbType.Binary);
  param.Value = signStream.ToArray();
  command.Parameters.Add(param);

  command.ExecuteNonQuery();
  connection.Close();
}
Now we have the signature saved locally...
We may save the signature into another storage type like a file for example.

See the whole article here:  http://xman892.blogspot.com/2006/12/how-to-series-building-signature.html

 

“WPF/E” is the Microsoft solution for delivering rich, cross-platform, interactive experiences including animation, graphics, audio, and video for the Web and beyond. Utilizing a subset of XAML (eXtensible Application Markup Language)-based Windows Presentation Foundation technology, “WPF/E” will enable the creation of content and applications that run within multiple browsers and operating systems (Windows and Macintosh) using Web standards for programmability. Consistent with Web architecture, the XAML markup is programmable using JavaScript and works well with ASP.NET AJAX. Broadly available for customers in the first half of 2007, “WPF/E” experiences will require a lightweight browser plug-in made freely available by Microsoft.

The CTP contains the WPF/E plugin itself and SDK
There is a Macintosh version as well  

Links:
WPF/E Downloads
WPF/E Dev Center