One .NET Way shall resume normal programming (no pun intended) immediately.

Post from: One .Net Way

One .NET Way Is Alive!

ClientIDMode can be set at Page level or at Control level. Let’s follow with an example of a GridView control. We will set it’s ClientIdMode property to all available options and view the markup. We will bind our GridView to a collection of cities. A city class looks like this.

public class City
{
  public string Name { get; set; }
  public string Country { get; set; }
}

The collection itself can be initialized using this code.

List<City> cities =
        new List<City>
        {
            new City{ Name = "Sydney", Country = "Australia" },
            new City{ Name = "New York", Country = "USA" },
            new City{ Name = "Paris", Country = "France" },
            new City{ Name = "Milan", Country = "Spain" },
            new City{ Name = "Melbourne", Country = "Australia" },
            new City{ Name = "Auckland", Country = "New Zealand" },
            new City{ Name = "Tokyo", Country = "Japan" },
            new City{ Name = "New Delhi", Country = "India" },
            new City{ Name = "Hobart", Country = "Australia" }
        };

Source for our GridView looks like this.

<asp:GridView runat="server" ID="gridViewCities" AutoGenerateColumns="False">
  <Columns>
    <asp:TemplateField>
      <ItemTemplate>
        <asp:Label runat="server" ID="Label1" Text='<%# Bind("Name") %>' />
      </ItemTemplate>
    </asp:TemplateField>
    <asp:TemplateField>
      <ItemTemplate>
        <asp:Label runat="server" ID="Label2" Text='<%# Bind("Country") %>' />
      </ItemTemplate>
    </asp:TemplateField>
  </Columns>
</asp:GridView>

ClientIDMode = “AutoID”

Using this mode will generate the IDs as it has in earlier versions of ASP.NET.

<asp:GridView
        runat="server"
        ID="gridViewCities"
        AutoGenerateColumns="False"
        ClientIDMode="AutoID">

HTML generated by AutoID (showing only relevant part).

ClientIDMode = “Static”

Static mode outputs the same ID in HTML as specified in ASP.NET source.

<asp:GridView
        runat="server"
        ID="gridViewCities"
        AutoGenerateColumns="False"
        ClientIDMode="Static">

Static Mode is not the best for controls such as GridView or any other data control which displays lists of data. As you can see above that all span tags have same IDs. Static Mode is best to be used with other common controls or User Controls.

ClientIDMode = “Predictable”

Predictable mode concatenates the ID of parent control with the bound value supplied by assigning ClientIDRowSuffix property.

<asp:GridView
        runat="server"
        ID="gridViewCities"
        AutoGenerateColumns="False"
        ClientIDMode="Predictable"
        ClientIDRowSuffix="Name">

Here we see that our span elements have been named by concatenating the name of GridView + value of Name property. Rather than setting ClientIDRowSuffix to Name property a better candidate would have been an ID property which could be some sort of unique field. But you get the idea, right?

ClientIDMode = “Inherit”

Inherit is the default mode for all controls. Assigning this mode a control will use the same setting as its parent control. This gives us an idea that we can have different settings for parent and children. Here we are setting ClientIDMode for our first label to be static while the GridView is using AutoID.

<asp:GridView runat="server" ID="gridViewCities" AutoGenerateColumns="False" 

  ClientIDMode="AutoID">
  <Columns>
    <asp:TemplateField>
      <ItemTemplate>
        <asp:Label runat="server" ID="Label1" Text='<%# Bind("Name") %>' 

          ClientIDMode="Static" />
      </ItemTemplate>
    </asp:TemplateField>
    <asp:TemplateField>
      <ItemTemplate>
        <asp:Label runat="server" ID="Label2" Text='<%# Bind("Country") %>' />
      </ItemTemplate>
    </asp:TemplateField>
  </Columns>
</asp:GridView>

We see that our first span uses static client ID but the second span uses inherited scheme for client ID.

Conclusion

In this post we saw a new feature of ASP.NET 4 which let’s you customize IDs generated in HTML elements. This feature is useful when we need to access controls from client scripts. ASP.NET has been lacking such a feature. Not any more.

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Working With Client ID In ASP.NET 4

1. Managed Languages
2. ASP.NET 4.0
3. Data Platform
4. WCF & WF
5. Parallel Computing
6. ALM

Link to Visual Studio 2010 and .NET Framework Training Course.

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Learn .NET 4.0 And Visual Studio 2010 On Channel 9

Let’s follow this post with an example of a simple program which uses a loop to add a number to a List<int>.

static void Main(string[] args)
{
  List<int> numbers = new List<int>();
  for (int i = 0; i < 100; i++)
  {
    numbers.Add(i);
  }
}

We will now add a breakpoint to numbers.Add(i) line. A breakpoint can be added by clicking on gray area on the left side of code editor or by pressing F9.

Here we have added a simple breakpoint. Our program will break when we hit the breakpoint for the first time. Let’s say that we want our breakpoint to hit at 50 iteration of our loop. To do this we can right click on the breakpoint circle on left hand side and click Hit Count.

When we click on Hit Count we get a dialog where we can set the conditions when our breakpoint should be hit.

In our case we will select “break when the hit count is equal to” and enter 50.

If we now run our program we will hit the breakpoint when value of i = 49. Remember that we started i at 0 so when i is equal to 49 we are on the 50th iteration.

This comes in handy when debugging large loops and we are only interested in breaking when we have processed X number of iterations.

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Create Breakpoints With Hit Count In Visual Studio 2008

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Windows 7 Commercial – More Happy Is Coming

XSLT parser does not like the code above and gives me this error.

After scratching my head for a while and navigating through intellisense few times I found the right solution. The way to output DOCTYPE in XSLT is by placing in inside a CDATA. The following code works like a charm.

This I thought was worth sharing.

Post from: One .Net Way

Output DOCTYPE In XSLT

The best presentation of the day which I attended was by Damian Edwards on ASP.NET MVC. Well structured and full of useful information. ASP.NET MVC is my current focus and that made the presentation even more interesting for me . Well done Damian.

I also attended a talk on BizSpark by Rog42 and Christian Longstaff. Biz Spark is a great program for startups and if you are one then you should definitely look at it. Where else can you get a suite of world class software at $100 which is payable in third year. I’m thinking that I might consider it for my company.

I also enjoyed Sharepoint presentation by Andrew Coates and Jeremy Thake. Their presentation was well synchronised and full of Sharepoint goodness. I’m not too much into Sharepoint but even I picked up points which I could use if god forbid I have to do any Sharepoint work again.

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TechEd Australia Day 2

Day 1

Technically today was not the first day of TechEd but it was for me. I arrived at Gold Coast after a pleasant 1 point something hour flight. Meeting familiar people at Gold Coast airport who were also headed to TechEd got me into TechEd groove right away. I checked into my hotel which is in front of Convention Centre and the best part is that I can get a panoramic view of Convention Centre from my window. Wasting no time I went straight to Convention Centre for registration and picked up my Netbook, picked up my delegate bag (to be reviewed soon) and headed to exhibition hall where I caught up with Rob Farley and finally met Deeps. For those who have confused me with Deeps I can now logically prove that we are two different people. Exhibition hall was buzzing with activity and you could feel geek vibes all over the place.

I took some pictures which you can view down below. But before you do that I have a WTF to report on. Drums please. WTF for today was found inside delegate bag within HP folder. There is a pamphlet which says HP recommends Vista Business.

Registration booths at TechEd Australia.

Me holding my HP Netbook. Still in the box.

My friend Rob Farley holding my Netbook.

Netbook right out of the box. Not booted yet.

More tomorrow…

Post from: One .Net Way

TechEd Australia Day 1

In this post I will use a simple Windows Forms application which adds two numbers.

By default a Windows Forms application does not output to a Console even if you write a Console.Write() or Console.WriteLine(). This shortcoming can be addressed by using Win32 API. In your Windows Forms application you can declare a class which provides a wrapper around Win32 functions.

public class Win32
{
  /// <summary>
  /// Allocates a new console for current process.
  /// </summary>
  [DllImport("kernel32.dll")]
  public static extern Boolean AllocConsole();

  /// <summary>
  /// Frees the console.
  /// </summary>
  [DllImport("kernel32.dll")]
  public static extern Boolean FreeConsole();
}

A Console must be started to accept input and display our messages. This can be done by calling Win32.AllocConsole() function. For my example I will start the console in my form’s constructor.

public Form1()
{
  InitializeComponent();

  Win32.AllocConsole();
}

Now when I write to Console, I will see data appear in the console window which was started in my constructor.

private void Add(int num1, int num2)
{
  int result = num1 + num2;

  Console.WriteLine(
    string.Format("{0} + {1} = {2}", num1, num2, result));
}

As a good practice you should also close the console window by calling Win32.FreeConsole() method before your application exits.

Post from: One .Net Way

Output To Console In Windows Forms Application

One thing to keep in mind is that filter expressions are case sensitive. And the syntax of applying filters in ADO.NET Data Services is

<url>?$filter=<your filter>

Let’s now look at all logical operators

Equal To

Parameter: eq

Equal To evaluates true when both operands have the same value. Here I am retrieving products where the value of Color matches “Yellow”.

http://localhost:6803/DataService.svc/Product?$filter=Color eq ‘Yellow’

Logical operator can also be applied in code through a LINQ query.

AdventureWorksEntities context = new AdventureWorksEntities(uri);
DataServiceQuery<Product> products = context.CreateQuery<Product>(@"/Product");

var query = from p in products
  where p.Color == "Yellow"
  select p;

foreach (var item in query)
{
  Console.WriteLine(item.ProductID + "\t" + item.Color);
}

Not Equal To

Parameter: ne

Not equal is opposite of equal to and evaluates true when both operands do not have the same value. Here I am retrieving products where the value of Color is NOT “Yellow”.

http://localhost:6803/DataService.svc/Product?$filter=Color ne ‘Yellow’

Following code will also achieve the same result through a LINQ query.

AdventureWorksEntities context = new AdventureWorksEntities(uri);
DataServiceQuery<Product> products = context.CreateQuery<Product>(@"/Product");

var query = from p in products
  where p.Color != "Yellow"
  select p;

foreach (var item in query)
{
  Console.WriteLine(item.ProductID + "\t" + item.Color);
}

Less than

Parameter: lt

Less than evaluates true when first operand is less than second. In this example I get all products where ListPrice is less than 20.

http://localhost:6803/DataService.svc/Product?$filter=ListPrice lt 20

Here is the C# version of Less than operator.

AdventureWorksEntities context = new AdventureWorksEntities(uri);
DataServiceQuery<Product> products = context.CreateQuery<Product>(@"/Product");

var query = from p in products
  where p.ListPrice < 20
  select p;

foreach (var item in query)
{
  Console.WriteLine(item.ProductID + "\t" + item.ListPrice);
}

Less than or equal to

Parameter: le

Less than or equal to evaluates true when first operand is either less than or equal to second operand. In this example I am retrieving all products where ListPrice is less than or equal to 9.5

http://localhost:6803/DataService.svc/Product?$filter=ListPrice le 9.5

And C# equivalent will look like this.

AdventureWorksEntities context = new AdventureWorksEntities(uri);
DataServiceQuery<Product> products = context.CreateQuery<Product>(@"/Product");

var query = from p in products
  where p.ListPrice <= 9.5m
  select p;

foreach (var item in query)
{
  Console.WriteLine(item.ProductID + "\t" + item.ListPrice);
}

Greater than

Parameter: gt

Greater than evaluates true if the first operand is greater than the second. In this example I am retrieving all products where ListPrice is greater than 9.5

http://localhost:6803/DataService.svc/Product?$filter=ListPrice gt 9.5

Greater than is a no brainer with a LINQ query.

AdventureWorksEntities context = new AdventureWorksEntities(uri);
DataServiceQuery<Product> products = context.CreateQuery<Product>(@"/Product");

var query = from p in products
  here p.ListPrice > 9.5m
  select p;

foreach (var item in query)
{
  Console.WriteLine(item.ProductID + "\t" + item.ListPrice);
}

Greater than or equal to

Parameter: ge

Greater than or equal to evaluates true if the first operand is greater than or equal to second. Here is  an example. I am retrieving all products where ListPrice is greater than or equal to 9.5

http://localhost:6803/DataService.svc/Product?$filter=ListPrice ge 9.5

C# example

AdventureWorksEntities context = new AdventureWorksEntities(uri);
DataServiceQuery<Product> products = context.CreateQuery<Product>(@"/Product");

var query = from p in products
  where p.ListPrice >= 9.5m
  select p;

foreach (var item in query)
{
  Console.WriteLine(item.ProductID + "\t" + item.ListPrice);
}

And

Parameter: and

“And” evaluates true when both operands are true. In this example I am retrieving all products where the Color is Black and ListPrice is greater than 1000.

http://localhost:6803/DataService.svc/Product?$filter=(Color eq ‘Black’) and (ListPrice gt 1000)

Same results can be retrieved in C# with this code.

AdventureWorksEntities context = new AdventureWorksEntities(uri);
DataServiceQuery<Product> products = context.CreateQuery<Product>(@"/Product");

var query = from p in products
  where (p.Color == "Black")
    && (p.ListPrice > 1000)
  select p;

foreach (var item in query)
{
  Console.WriteLine(item.Color + "\t" + item.ListPrice);
}

Or

Parameter: or

“Or” evaluates true when either operand is true. In this example I am retrieving all products where either the Color is Black or ListPrice is greater than 1000.

http://localhost:6803/DataService.svc/Product?$filter=(Color eq ‘Black’) or (ListPrice gt 1000)

Now with C#.

AdventureWorksEntities context = new AdventureWorksEntities(uri);
DataServiceQuery<Product> products = context.CreateQuery<Product>(@"/Product");

var query = from p in products
  where (p.Color == "Black")
    || (p.ListPrice > 1000)
  select p;

foreach (var item in query)
{
  Console.WriteLine(item.Color + "\t" + item.ListPrice);
}

Not

Parameter: not

“Not” evaluates true if operand is false. An example can be retrieving all products where the Color is not Black.

http://localhost:6803/DataService.svc/Product?$filter=not (Color eq ‘Black’)

While this can be achieved using not equal to operator they are not the same. I’ll leave C# code for this one for you :)

Conclusion

This article demonstrated all logical operators available for ADO.NET Data Services. In a future post I will cover other types of operators for ADO.NET Data Services.

Post from: One .Net Way

ADO.NET Data Services Logical Operators