ref c#

C# > Keywords > ref

The ref method parameter keyword on a method parameter causes a method to refer to the same variable that was passed into the method. Any changes made to the parameter in the method will be reflected in that variable when control passes back to the calling method.

using System;

public class MyClass
{
   public static void Ref(ref char x)
   {
      // The value of i will be changed in the calling method
      x = 'a';
   }
   public static void NoRef(char x)
   {
      // The value of i will be unchanged in the calling method
     x = 'b';
   }
   public static void Main()
   {
      char i = '';    // variable must be initialized
      Ref(ref i);  // the arg must be passed as ref
      Console.WriteLine(i);
      NoRef(i);
      Console.WriteLine(i);
   }
}

How to use the Desktop Alerts feature in Outlook

To open the settings dialog box for the Desktop Alerts feature, follow these steps:

1. On the Tools menu, click Options.
2. On the Preferences tab, click E-mail Options.
3. Click Advanced E-Mail Options.
4. Click Desktop Alert Settings.

In the Desktop Alert Settings dialog box, you can configure the duration and the transparency of your Desktop Alert notifications for when a new e-mail message is received. To turn off the Desktop Alerts feature, click to clear the Display a New Mail Desktop Alert check box.

Note You only receive Desktop Alert notifications if you have Microsoft Exchange server and Post Office Protocol version 3 (POP3) profiles. Internet Mail Access Protocol version 4 (IMAP4) and HTTP accounts do not support the Desktop Alerts feature.

?? Operator (C# Reference)

C# > Operators > ?? Operator

The ?? operator,also called the null-coalescing operator, returns the left-hand operand if it is not null, or else it returns the right operand.

Example

// y = x, unless x is null, in which case y = 0.
int y = x ?? 0;

Parental Controls on Internet Explorer

Parental Controls on Internet Explorer

1. Go to Internet Explorer on your computer. Click on 'Tools' from the toolbar in the upper right-hand corner of the Web browser. Click on 'Internet Options'

2. Select the 'Content' tab.

3. Find the 'Content Advisor' heading and click on the button labeled 'Enable.'

4. Choose a category from the list. This list will present you with a variety of content categories that you may not want your children to see, such as sites depicting drug or alcohol use, violent images, nudity or bad language.

5. Click on the category you want to control. Then use your mouse to move the slider below the list to set the degree of restriction you want on that type of site. the degree of restriction can range from no restriction at all to the complete blocking of those sorts of sites.

6. Click 'OK.'

7. Set a password. You will be prompted to do so at this point. Setting a password will ensure that no one but you is able to adjust the parental control settings.

Restart IIS from asp net page

ASP.NET

ServiceController represents a Windows service and allows you to connect to a running or stopped service, manipulate it, or get information about it.
The Internet Information Services (IIS) World Wide Web Publishing Service (W3SVC) manages the HTTP protocol and HTTP performance counters.

Example :
Restart IIS from asp net page

using System;

using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.ServiceProcess;
using System.Threading;

namespace WebApplication1

{
    public partial class _Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            ServiceController sc = new ServiceController("W3SVC");
            if (null != sc)
            {
                if (sc.Status == ServiceControllerStatus.Running)
                {
                    sc.Stop();
                    Thread.Sleep(2000);
                    sc.Start();
                    Response.Write("IIS restarted");
                }
                else
                {
                    Response.Write("IIS started");
                    sc.Start();
                }
            }
        }
    }
}

 

ISNUMERIC SQL Server

SQL Server > Built-In Functions > ISNUMERIC

ISNUMERIC returns 1 when the input expression evaluates to a valid numeric data type; otherwise it returns 0

Example:

IF OBJECT_ID(N'tbl1', N'U') IS NOT NULL

       DROP TABLE tbl1;
GO

CREATE TABLE tbl1

(
       id     int ,
       code   varchar(50)
);
GO

INSERT INTO tbl1 values  (1,'aaa'), (2,'b12') , (3,'345')

SELECT
       *
FROM
       tbl1
WHERE
       ISNUMERIC(code) = 1

Result:

 

id code
3  345

 

 

C# Nullable DateTime

C# > System Namespace > DateTime > Nullable DateTime

// Error Cannot convert null to 'System.DateTime' because it is a non-nullable value type 
   

DateTime AgendaValidFrom;

AgendaValidFrom = null;

Solution:
Add ? to DateTime

DateTime? AgendaValidFrom = null; // Declare a nullable DateTime instance and assign to null.