ASP.Net fix

If you have a string, like this:

string str = "Line 1\n   Tab it.\t Break.\n'

How to remove breakline or tab in this string? 

So you can using some methods:

Method 1: quick to code

string newstr = Regex.Replace(str, @"\t|\n|\r", ""); // \t is tab, \n and \r is new line

Method 2: for New line only

string newstr = str.Replace(Environment.NewLine, "");

Method 3: Easy to code

str = str.Replace("\n", String.Empty);
str = str.Replace("\r", String.Empty);
str = str.Replace("\t", String.Empty);

Method 4: For speed and low memory, because is StringBuilder best!

var sb = new StringBuilder(s.Length);

foreach (char i in str)
    if (i != '\n' && i != '\r' && i != '\t')
        sb.Append(i);

str = sb.ToString();

You want to remove characters \ /:*?"<>|!@#$%^&() from a string?
Very easy! Follow some method:

1. Remove all special characters

string rExp = "[^\w\d]";
string tmp = Regex.Replace(n, rExp, "");

2. Remove all special characters but allow some
Example: Allow . and _

Regex.Replace(input, "[^a-zA-Z0-9._]", string.Empty)

3. Easy function remove all special characters, but allow "_"

 public static string Remove_Special_Characters(string str)
        {
            StringBuilder sb = new StringBuilder();
            foreach (char c in str)
            {
                if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_')
                {
                    sb.Append(c);
                }
            }
            return sb.ToString();
        }

(Continue with fix-debugger-not-working)
When I going to debug with Visual Studio 2010, It work!
But when I want to run line by line at break point. I press F11 and F10... => It not work!!!

Solutions to fix:
1. Install http://support.microsoft.com/default.aspx/kb/957912
2. Change the port of the Visual Studio development server (go to menu Project > Properties > Web > *Server: User Visual Studio Development Server: Specific port = 12345)

Today, my friend ask me: "What is ops/sec?"
:D

ops/sec is operations per second. When you test benmark. It's meanoften how many time execute a test in a second.

ops/sec often using for benchmark devices as smartphone, GPU, CPU, read write disk, or test for framework,...

Now you can answer "What is ops/sec?"!

You want to remove characters \ /:*?"<>|!@#$%^&() from a string?
Very easy! Follow some method:

1. Remove all special characters

string rExp = "[^\w\d]";
string tmp = Regex.Replace(n, rExp, "");

2. Remove all special characters but allow some
Example: Allow . and _

Regex.Replace(input, "[^a-zA-Z0-9._]", string.Empty)

3. Easy function remove all special characters, but allow "_"

 public static string Remove_Special_Characters(string str)
        {
            StringBuilder sb = new StringBuilder();
            foreach (char c in str)
            {
                if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_')
                {
                    sb.Append(c);
                }
            }
            return sb.ToString();
        }

One day, you are coding... And run it! But an error show!

Could not load file or assembly 'Microsoft.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.

You don\'t worry! And try some solutions

1. Review web.config

- Install the latest Asp.NET Ajax - Open my web.config in my production server and replace this line

<add assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"></add> 

by

<add assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"></add> 

PublicKeyToken is in capitals....

2. Check your bin folder
Copy the System.Web.Extensions.dll into the app's bin directory if you have.

 3. Install ASP.NET AJAX 1.0
Check you had install it? If not, you download it at ASP.NET AJAX 1.0 

4. If you using Ajaxcontrol toolkit
Download and install it at Ajaxcontrol toolkit

Try one solution or try all until you resolve an error!

Oh! No...
When you coding with .Net. Many time you meet an error: "object reference not set to an instance of an object".
What happen???

Example 1: Convert null to int

string query = "Select * from USERS where ID = '" + txtUID.Text + "'";
SqlCommand cmd = new SqlCommand(query , CN);
int count = (int)cmd.ExecuteScalar();//Error here

What problem? ExecuteScalar return to null when record not found in database. In case, you can using Convert class

Convert.ToInt32(cmd.ExecuteScalar());//It will return 0 when ExecuteScalar() return null

Example 2: Try get object properties when this object is null

var str= null;
if(str!="")// Error here
{
//do some thing
}

Resolve the problem: You can try

var str= null;
if(str !=null && str!="")// Error here
{
//do some thing
}

Or try this

var str= null;
if(!String.IsNullOrEmpty(str))// Error here
{
//do some thing
}

Example: Very much error!

// About 10000 lines

Resole all with

try{
//All code here
}
catch (NullReferenceException ex)
        {
            ShowMessageBox("Error" + ex.Message);
        }