The designer cannot process the code at line 37: this.comboBox1.Items.AddRange(new []{ “one”, “two”, “three”, “four”}); The code within the method ‘InitializeComponent’ is generated by the designer and should not be manually modified. Please remove any changes and try opening the designer again.

If I commented the AddRange line it was working fine or It was pointing at the next line those had AddRange method. I quickly googled for the solution and found many but none of the fix was useful. By careful observation I found that something was missing the line. See if you can observe what’s missing the below line

 this.comboBox1.Items.AddRange(new []{
“one”,
“two”,
“three”,
“four”});

Just adding the type of the array that I was creating solved my problem, for above problem I added new object[] and then all worked fine.

this.comboBox1.Items.AddRange(new object[]{
“one”,
“two”,
“three”,
“four”});

After fixing the issue I started searching for the person who had removed it, I wanted to show him the issue so that he will not do the same next time. After searching for hours I found that it was Mr. ReSharper who had removed the type. From then I started carefully using Resharper instead of just clicking on what it suggests.

Download Source code (13 Kb)

I have made a separate dll (CustomPackage.dll) that you can use for zipping and unzipping of folders. I have also created a dummy project PackageWrapper to help you understand how to make calls to the dll.

Features:

• The project supports Unicode characters in folder or files (Limitation with Cabarc.exe)
• Zipping is done also for all sub directories . While unzipping the same directory structure will be maintained.

Improvements for you to do:
I have used Mime Type as MediaTypeNames.Application.Octet to make it generic and support all kind of files and have used the compression option CompressionOption.NotCompressed since the mime type will not compress. If you know that you will have only similar type of files to zip or unzip then you can select proper Mime type and compression option as CompressionOption.Maximum to compress the files to maximum extent.

For any kind of improvements or clarifications please feel free to comment.

Happy Coding
Codingsense

Its given in microsoft patterns and practices to consider replacing recursion with looping because each recursive call adds data to the stack. Examine your code and see if your recursive calls can be converted to a looping equivalent.

I was wondering if all the solutions that uses recursion can be replaced without using recursion.
So I took the first step in looking into my project and found a piece of code that was using recursion, a function that would give me all the controls on a windows form. So I decided trying to convert that code without the use of recursive call.

Here is what I came up with,

static IList getControls(Control ParentControl)
{
List<Control> ListOfControls = new List<Control>();
List<Control> ContainerControls = new List<Control>();
ContainerControls.Add(ParentControl);

while (ContainerControls.Count > 0)
{
foreach (Control control in ContainerControls[0].Controls)
{
if (control.Controls.Count > 0)
{
ContainerControls.Add(control);
}
ListOfControls.Add(control);
}
ContainerControls.Remove(ContainerControls[0]);
}
return ListOfControls;
}

Great, the method gave me proper result as compared with the recursive function, what next I wanted to see how it has increased in performance and I used stopwatch to determine the time taken by both of the methods on the same form which was heavily loaded with controls and containers, it had 82 controls on it. The time taken by recursive function was double the time taken by the new method.

So I concluded that replacing recursive method with looping will enhance performance and also helps in consuming less memory.

If you get a better way to overcome recursion then please feel free to comment, till then I will continue my search for more recursive calls in my code.

While registering a com dll using RegSvr32 I encountered the following problem in Windows 7

Problem:
The moduleThe module “D:\..\support files\..\abc.dll” was loaded but the call to DllRegisterServer failed with error code 0×80020009.
For more information about this problem, search online using the error code as a search term.

Solution:
1) I opened command prompt in administrator mode. ( Always open the cmd.exe in administrator mode while registring a dll in Vista or Win 7, Steps – Type cmd in search box, when cmd is listed in the above list, right click it and click open as administrator)
2) The folder “Support files” was having a space so it failed to locate it. I navigated to the support files and then used regsvr32 command and all worked fine

Happy Learning,
CodingSense

Download FxCop

SInce FxCop analyses IL code from your assemblies, we should know about some of the keywords of IL to write complex rules. Use this sheet as a reference while seeing your IL code through ILDASM.

I have created a template project for Custom FxCop Rules for you which you can use and add your rules. So that you can concentrate more on Custom Rules rather than creating the project.

Download CustomFxCopRules template

If you want to add any new rule you have to follow these steps using the above template.

1. Create a class and name it with the rule.
2. Create a new node of that of the classname (not necessary but only for easier reference) in CustomRules.xml with desired settings
3. Create a constant with the same name and value in Constants.resx file
4. Write your logic in that class

And to debug the rules that you have written here is a post
http://social.msdn.microsoft.com/forums/en-US/vstscode/thread/b92a0416-bf20-40c1-88a0-8fcff07133dc/

More References:
http://www.binarycoder.net/fxcop/pdf/fxcop.pdfhttp://www.binarycoder.net/fxcop/pdf/fxcop.pdf
http://www.nmentor.com/Blog/Tutorials/1.%20How%20to%20Write%20Custom%20FxCop%20Rule.pdf

I will put some of the custom rules in coming post which willl cover all the required topics to make you understand FxCop better. If you want any specific rule, then feel free to post a comment to me and I will help you out

Happy Learning
Codingsense

We should have Comments for

1. Classes
• What does the class do?
• Which other classes are used by it?
2. Methods
• What does the method do?
• What are the inputs and return type?
• What changes to the system is done by that method (if it is updating a database or xml file or a static variable of some other class etc)
3. Comment Complex lines
• Emphasis more on why the below line is required than what the below line does (e.g. assume the scenario in which we are iterating a list and we are incrementing the List index by one, instead of writing the obvious “Increment the index by one” write “move to the next element in the list by incrementing the index by one”)
• Write comments to only the lines which are not obvious. Comments will be required majorly for algorithms or if it’s changing the behavior of a system.
4. Give appropriate names to variables and Methods
• Giving proper names to variables and methods for what it does help to understand the obvious lines much better, avoid comments for such lines. Like if I have a variable named hasOperationFailed, by just looking it I can be sure that it’s a Boolean fields and while checking the conditions like If(hasOperationFailed) makes me understand what condition am I checking.
5. Read the comment twice after writing
• This may seem to waste time but trust me, after reading the written comment again we tend to re write the lines many times. Since the value of comments can only be said by the reader who uses it. So if the lines are simple to understand and appropriate then your efforts will be considered.

There are software’s that fetches the comments from your code and gives the output in different formats so that you can verify your comments and it can be used as a guide for what your classes and methods does.
Here are the list of some

• SandCastle
• NDoc

Other references:
http://www.codeproject.com/KB/XML/csharpcodedocumentation.aspx?msg=1679454

Happy learning,
Codingsense

Last week I was optimizing a module, as I was working I found that if exceptions are avoided then we can save lot of fruitful time. So made the below sample to see how much time we can save by avoiding an exception.

In below sample a method just iterates and another method throws an exception.

using System;

namespace ConsoleApplication1
{
class Program    
{
static void Main(string[] args)
{
System.Diagnostics.Stopwatch sw = new System.Diagnostics.Stopwatch();

sw.Start();
loopProper();
sw.Stop();
Console.WriteLine("Looping Time : " + sw.ElapsedMilliseconds);

sw.Reset();
sw.Start();
ThrowException();
sw.Stop();
Console.WriteLine("Exception not hanlded Time : " + sw.ElapsedMilliseconds);

Console.Read();
}

static void loopProper()
{
for (long Index = 0; Index < 350000; Index++)
{

}
}

static void ThrowException()
{
long Temp = 0;
long Zero = 0;

try            
{
Temp = Temp / Zero;
}
catch (ArithmeticException ex)
{

}
}
}
}

After running the above sample we can find that an time taken by just one exception is approx around time taken by 3,50,000 iterations. So if we can avoid exceptions then we can do more fruitful work in the same time.

I dont mean that exception handling should not be used, but try to avoid it to maximum. If you can use some if conditions where you know the line might give an exception, and see how the performance increases.

Any about my output, the module had a algorithm that would take 80-85 sec to complete and after optimization its taking 2 sec to complete. Changes in logic of the algorithm and exception handling increased the performance drastically.

Happy learning,
Codingsense

I was working on a multithreading application and found an interesting thing on resuming a thread, so planned to share with you.

When a thread is running if we abort it, it gets stopped. But if a suspended thread is aborted then it gives an exception “Thread is suspended; attempting to abort”.

The below sample demonstrates it, first the thread is started, then suspended and then aborted. Run the application and check the error.

using System;
using System.Threading;

namespace ConsoleApplication1
{
class Program    
{
static void Main(string[] args)
{
Thread thread = new Thread(new ThreadStart(DoSomething));
thread.Start();

for (int Index = 0; Index < 10; Index++)
{
switch (Index)
{
case 4:
thread.Suspend();
Console.WriteLine("Thread suspended");
break;

case 6:
thread.Abort();
Console.WriteLine("Thread aborted");
break;

}

//Main Thread is made to sleep                
Thread.Sleep(300);
}

Console.Read();
}

private static void DoSomething()
{
while (true)
{
Thread.Sleep(300);
Console.WriteLine("I am busy doing work");
}
}
}
}

To overcome this exception we can use Resume to invoke the suspended thread and then abort.
Replace the case 6 with below code snippet.

case 6:
try                        
{
thread.Abort();
}
catch (ThreadStateException)
{
thread.Resume();
}
Console.WriteLine("Thread aborted");
break;

now running the application aborts the thread as expected.
From this sample we can learn that if we use resume on a suspended thread then it starts again, but if we have signalled for abort on that thread and try resume then it will stop the thread in proper manner.

Happy Learning
Codingsense