Some of the books in my collection

Most of the things I know are from internet blogs and community and from practical experience of me or other people.

Still I like reading books and for in depth knowledge it is something you can not skip. Here I am sharing some of the books I have (I am reading them too) and some of the books I wants to buy soon.

I have already

1. Code Complete 2nd Edition.
2. Joel on Software.
3. More Joel on Software.
4. LINQ in action
5. Silverlight 2 in action.
6. C# 3.0 in a Nutshell.
7. C# in depth.
8. CLR via C#
9. JavaScript the good parts.


I want to buy

1. Mastering Regular Expression.
2. The Pragmatic Programmer.
3. JQuery in Action.
4. Data Driven Services with Silverlight 2.
5. Dont make me think.

I have already read some parts of Code Complete, Mastering Regular Expression from library and I can tell you these two books are great.

As you might seen I only have one book on Silverlight. I could not start this book yet. I will let you know more about the books when I finish them.

Please share your favorite books too.

Silverlight and LINQ

I got a thread in Silverlight forum that asks how to select a row in a DataGrid?

Now here is the ans using a simple LINQ query.

MyClass item = MyDataGrid.ItemsSource.Cast().Where((_, pos) => pos == row_number).SingleOrDefault();

Now we have the data grid named MyDataGrid and we have already populated it with a collection of MyClass. We are using extension methods of C# 3.0 to help us select a row where row number is known.

In the lambda expression (_, pos) => pos == row_number

we do not care about the first parameter so I have replaced it with '_'. (Remember '_' is a valid C# identifier).

LINQ has a great power to make your code compact and less error prone. Still I see many people using lengthy (Wrong?) way of doing simple things like selecting from a list where the list value satisfy a certain condition. Many people still things LINQ as an Syntactic Sugar of SQL queries. You can obviously use LINQ to SQL for interacting with database but LINQ is not only that.

LINQ comes in handy while parsing XML too.

Other benefits are like Sorting, advance selection and searching.

Silverlight kid is here.......

Hi All,
I was never interested in coding but the moment my mentor Mr. Deepak Sharma asked me to learn silverlight, I fell in love with it. The first thing which I ever made in my life was a christmas card in silverlight 1.0, and fortunately everybody liked it. From then onwards there was no looking back.I continued to experiment with it. Silverlight has cast a spell on me and Tanmoy has always increased my interest in it .And now when Tanmoy asked me to contribute in this blog, I was thrilled.I would try to keep this spirit of silverlight alive in me and would try to enlighten others with the knowledge I acquire in this journey.
Thanks to Tanmoy!

Introducing Ramya...Another Silverlight Geek

Hi,
to make this blog more effective I requested Ramya to join this blog. She has started her programming career with Silverlight and proved excellence in a very short time. Its a great thing that from now we two will be reviewing our posts and can keep posting while the other one is busy. It will increase the quality and number of posts.

Silverlight rocks as she does.

Lets welcome her....

~Tanmoy

Silverlight 3 Wish List ---- What We Got

Hi all,

Silverlight 3 Beta is released. Now it does fulfill many of the features that the community has hoped for. Joe Stegman has marged the Silverlight 3 wish lists from different sources (Including the thread I have started) and put them in a table sorted on popularity. Lets check it with what we got. This is partial and please help me complete it and let me know in cases I am wrong.

Feature	Count	Comments	Status	Note
Web camera and/or microphone input	33	Includes requests for just microphone as well	No
Bitmap APIs	26	Support get/set pixels and/or rendering a XAML scene to a bitmap.	Partial. (After reading the comments and in forums and agree with it)	Check this application.
Full 3D	24	Full 3D support (full 3D models)	Partial	Video1 Video2
Printing	20	Printing APIs	No
Offline and/or out of browser support	16	Support running Silverlight when not online (or completely out of the browser)	Yes	Video
Bi-directional text and/or complex script	9		No
UDP/P2P	9	UDP APIs generally for Peer to Peer support	No
Rich text support	8	Editing and display	No
Right mouse button	8	Ability to configure the right click	No
Text quality	8	Improved text quality	Partial	Clear type will be supported
HTML Integration	7	Support HTML hosting (live HTML documents) and/or HTML translation	No
Interactive designer	7	Support an interactive designer in Visual Studio	No	Will be with VS 2010
Support more than BasicHttpBinding	7	Most common request is for WSHttpBinding	No
Improve Silverlight/WPF compatibility	6	Mostly feature requests for either Silverlight and/or WPF	Partial	Gap is reducing over time
More controls	6	Random/general requests	Yes	With the new toolkit release it increases.
SaveFileDialog	6		Yes
Data and/or property triggers	5		No
Reporting services	5		No
Synchronous web service calls	5		No	Is it really needed?
ADO.NET DataSet/DataTable	4		Partial	Check out new data controls and RIA services.
Alpha video	4	Chroma key support
Clipboard support	4		No	Some people think of it as security threat. Workaround
Drawing APIs (immediate mode)	4			Pixel effects?
Element name binding	4			Element to element binding is now possible.
Improved DataGrid	4	Several different requests
Local relational database (SQL)	4
Modal dialog	4
Mouse wheel	4	API and support in existing controls	No	Helper class available
Selectable text	4
Assembly caching	3	Want a framework for downloading/managing assemblies	Yes	Here.
Credentials/auth	3	Requests for networking stack and ASP.NET type integration
Custom markup extensions	3		No
Multi-target DLLs for .NET/SL	3	Build a business object DLL once for both .NET and Silverlight	No
Multi-touch support	3
Path Animation	3		No
Speech and better audio decoder	3
VisualBrush	3		No
9 Grid	2
Better keyboard APIs	2	Platform independent keycode
Better SEO	2		Yes	Check this blog.
Binding support to anonymous types	2
Direct database access	2	OLEDB/ODBC equivalent	No
Flow panel	2
GIF support	2		No	Probably it wont be there. See what Pete Brown says.
Global/dynamic styles (skinning)	2
Integrated CTRL+F (in page search)	2
Sound APIs (equalizer)	2	Includes looping	No
TileBrush (Image Tiling)	2		No
XPS Support	2
64-bit platform support	1
Android support	1
Better N-tier support	1	Improved data access	Yes	RIA Services
Better SharePoint integration	1
Block style text	1	Bulleted lists, paragraphs	No	But check this out
Cell based animation	1
CollectionView	1
Color management	1
Digital/XAP signing	1
Double Click event	1		No	work around
Drag and Drop	1	Between the desktop and Silverlight	No
Full 5.1 sound	1	Currently fold down to stereo	No
IDataErrorInfo	1
Inverse kinematics (bones)	1	Flash 10 feature
MediaTimeline	1
Multi-binding	1
Navigation model	1	Includes browser history integration	Yes	Video
Validation controls	1		Yes	Check this.
XPATH support for data binding	1

Thanks...

Some Guidelines For Developing Silverlight Applications

Hi,
Here are some basic guidelines for building Silverlight applications. They are based on the problems I have faced and seen. Keep in mind none of them are rules, and you can (you should actually) follow only some of them as it suits.

1. Use source control :

---

Use source control even if you are solo developer.

2. Plan all user controls as early as possible:

---

Plan your modules early. This will help you plan how to do interaction between them early and you don't have to do some ad-hock fix later. Create them and have some basic methods like Initialize and Deinitialize inside them.(see point 5)

3. Separate each part into a user control:

---

a. It will help many people working in the same application without much side effect on another control.
b. It helps isolate any problem to a small region so that it would become easy to rectify it.
c. It helps reuse the same control in different places.

Add some classes for basic functionality like checking for URL format or parsing an xml. You can make separate library if they are big enough.

4. Loaded event is harmful:

---

Do not rely on the loaded events. Why? In one application I was adding and removing an user control when needed, dynamically from code. Each time I was not creating a new object. Instead I was reusing the same one. Now I have attached the MouseLeftButtonDown event inside the loaded event of that user control. What was happening is this. Each time I was adding the user control the loaded event was getting fired and the event was been attached again. So the event handlers are fired multiple times. So adding and removing the user control a few times was making the application run very slow. It took me a hell lot of time to find out why.

So where to put the event handlers? See below.

5. Initialize and Deinitialize :

---

Put one Initialize and one Deinitialize public method in every user control you make. It is useful in many ways.

a. You can add the event handlers and other code that must run only once inside Initialize
method.

b. You can pass parameters to Initialize method without disturbing the constructor signature
or adding a new constructor. So new YourUserControl ( ) will always work.

c. You can use Deinitialize method to clean up the control. This is specifically required when
you are showing some customized content to the user and need to change it when user
signs out or another user signs in.

Now while creating the user control for the first time you should call the Initialize method with proper parameters.

One disadvantage of this approach is it has the feeling of evil destructors in c++. You need to be careful while calling these two methods.

6. Don't put your event handlers from xaml:

---

While is perfectly legal to add event handlers from xaml it is better to do it from code. Reason is...

a. Xaml belongs to designers. Event handling belongs to programmers. So its easy to attach
or detach event handlers from code without disturbing the xaml.

b. Suppose you have attached event handler to a control from code. Now if the name of the
control is changed or the control is been removed from xaml you will get an compilation
error with clear meaning. Now if you have written the event handler from xaml and
removed the appropriate method from code you will get an exception with less clear
message.

7. Select your layout carefully:

---

Take time to select proper layout. I can assure you it will save a lot of your time debugging later. Take your design mock up and think about how you can make the layout. Understand advantages and limitations of Grid, StackPanel, Canvas, Border, Popup, ScrollViewer etc. Some tips for choosing layout.

a. Most of the time you will find Grid is suitable for the top level container (root). This is specially true if your Silverlight application is occupied total page. You will find it containing header, footer and sometimes left and right module. These can be easily done with dividing main root grid with columns and rows.

b. For very complex structures inside the application you will find Canvas is best fitted. Specially if its height width is specified and has overlapped controls inside it.

c. While you are dividing your grid with rows and columns sometimes you will find you need only columns or only rows. Its time for choosing a StackPanel with proper orientation specified. StackPanel also adjust its children while new child is added or removed.

Though its personal preference I prefer to do the top level layout from Visual Studio or at least check the xaml structure in visual studio after making it in blend. It helps prevent some properties getting set automatically without your knowledge and to remove redundant code.

8. Avoid specifying height and width explicitly:

---

Make your application layout such a way you don't have to specify height and width for each control. Grid has many flexible features like Horizontal and Vertical Alignments, Row and Column properties. Use them wisely. If you make your layout structure carefully you will find most of the time you can avoid using height, width and margin. Also try to avoid negative values in margin. Most of the time it means you have chosen wrong horizontal alignment or vertical alignment property.

9. Don't put any secret inside your code:

---

Silverlight is a client side technology. Keep in mind all your code goes into users machine and can be easily decompiled to view the code. So never put any sensitive data inside code. Security is the most critical part in today's internet. Security is invisible as long it protects you but it is needed most. Think carefully and from the design phase of your application about security. Don't rely on security through obscurity.

10. Test individual user control:

---

After creating a user control run it directly from app.xaml.cs by setting the root visual to the control. Call initialize method with proper arguments and check if it works as expected. Test the application thoroughly and fix the slightest defect you found.

11. Don't use image as a button:

---

In Silverlight 1.0 we did not have any button control so we used some xaml or image for button.
In Silverlight 2 use a button and style it appropriately. It helps in the following way...

a. Maintaining states like mouse over or pressed.
b. Basic functionality like click. (No, click is not same as MouseLeftButtonDown event)
c. Use the same style without copying whole xaml.

This is also valid for all other controls.


12. Don't put redundant code:

---

Your code should look beautiful. Remove redundant code and simplify the logic as fer as possible. Auto generated codes sometimes generates lot of extra code if you use them in a wrong way. Clean them up.

13. Performance:

---

a. Reduce your xap size.
b. Reduce the loading time for total or different parts of your application.
c. Avoid windowless=true.
d. Crate vector graphics for simple images.

14. Use web services for server communication:

---

Silverlight runs on users machine so can not interect with server or database directly. There are many ways of doing it but the best and easiest way is using web services.
Use WCF services if possible.

15. Use Isolated Storage, but carefully:

---

Use Isolated storage. But DO NOT put any sensitive data there.

Some More Tips

Here are some Tips.....

1. Reducing xap size

• Select Release in properties before moving the xap to the production and build.
• rename the .xap file to .zip. Extract the zip and then re-zip it. It generally decreases the size quite a bit.
• Use vector graphics instead of images.
• Load the assets on demand instead of packaging them in the xap.
  

2. How to set some value to Auto?

• You can set a value (Say Width of a canvas) to Auto in xaml. How can you do it from code? Set canvas width = double.NaN.
  

3. ObservableCollection

• You get a new type of collection with Silverlight, called ObservableCollection. You can use this type of collection wherever you normally use a list. Like setting the ItemsSource of a ListBox. The benefit of using this over List is that it automatically updates the Items whenever the collection changes. This is really helpful for data binding.
  

4. How to rotate something from its edge?

• Suppose you have a red rectangle. Now if you rotate it with a storyboard it will rotate like the below image. i.e from center of the rectangle.
  

Now you want to rotate it from its edge. You can see a small dot in the center of the rectangle like the following in blend design view when you select the rectangle.


That dot defines render transform origin or the origin of all the transformation that will be applied to the rectangle. Now you can drag the small dot to the edge of the stick and the stick (rectangle) will rotate from the edge like the below image.

5. How to set style from code?

• You can apply a style in xaml like the following. Style="{StaticResource ButtonStyleKeyName}". Now if you want to set it from code do like the following. MyButton.Style = (Style)Resources["ButtonStyleKeyName"];
  
• Remember you can set style only once. So if you are trying to do like MyButton.Style = (Style)Resources["ButtonStyleKeyName2"]; After setting the style for the first time you will get an exception.

6. Auto refresh page after silverlight installation.

• Suppose someone viewing your website and does not have silverlight installed. You prompt him to download and install it. Now after installing the silverlight the page should be auto refreshed so he can see your silverlight application. If you use object tag and include Silverlight.js file this behavior is default. This line in Silverlight.js determines that. Silverlight.onSilverlightInstalled = function () {window.location.reload(false);}; Set the parameter to true if you want to bypass the cache.
  
• Could not find a way of doing this with asp:Silverlight tag still. Please tell me if you know the way.
  

7. Double click support:

• Check it here.

8. Where are the dlls for Silverlight?

• The library dlls for Silverlight are in library folder inside Silverlight SDK. The default location for it is C:\Program Files\Microsoft SDKs\Silverlight\v2.0\Libraries. This is specially useful if you are adding any reference from Expression Blend.
  

9. How to make sure user does not get the old xap from the browser cache?

• There are many solution for this. One quick way is to Add a random number in the querystring of the xap source. for ie Source="~/ClientBin/RotateExp.xap?rnd=029db68e-02c0-4dc8-a4f9-81b09f8000da"
  

That's it for now. Happy New year. :)