LINQ FirstOrDefault C# Example

C# > LINQ > FirstOrDefault

Returns the first element of the sequence that satisfies a condition or a default value if no such element is found.

Example

string[] cars = { "audi", "ford", "mercedes", "dacia" };
string car = cars.FirstOrDefault(c => c == "ford"); //ford
car = cars.FirstOrDefault(c => c == "ford1"); //null

          

  

Single LINQ C# Example

C# > LINQ > Single

Returns the only element of a sequence that satisfies a specified condition, and throws an exception if more than one such element exists.

Example

            string[] cars = { "audi", "ford", "mercedes", "dacia" };
            try
            {
                string car = cars.Single(c => c == "ford");
            }
            catch (System.InvalidOperationException)
            {
                MessageBox.Show ("Car not found!");
            }

How To Programmatically Change Printer Settings for Internet Explorer and WebBrowser Control in C#

C# > Forms >  WebBrowser > ShowPrintPreviewDialog

How To Programmatically Change Printer Settings for Internet Explorer and WebBrowser Control in C#

Example:

Change margin right property.

string strKey = "Software\\Microsoft\\Internet Explorer\\PageSetup";

bool boolWritable = true;
string strName = "margin_right";
object oValue = "0";
RegistryKey oKey = Registry.CurrentUser.OpenSubKey(strKey, boolWritable);
oKey.SetValue(strName, oValue);
oKey.Close();

webBrowser1.ShowPrintPreviewDialog();

 

 

ROW_NUMBER SQL Server Example

SQL Server > Built-in Functions >  ROW_NUMBER

Returns the sequential number of a row within a partition of a result set, starting at 1 for the first row in each partition.

Example:

CREATE TABLE #LocalTempTable(

       ID            int,
       Name   varchar(50),
       Salary int,
       DeptId int)

insert into #LocalTempTable(Id, Name, Salary, DeptId) values (1,'p1',100,1),  (2,'p2',200,1) ,  (3,'p2', 500,2)

SELECT ROW_NUMBER() OVER(ORDER BY Id DESC) AS Row,

    Name, Salary
FROM
       #LocalTempTable;

-- specify number of rows

WITH tbl AS
(
    SELECT Id, Name,
    ROW_NUMBER() OVER (ORDER BY Salary) AS RowNumber
    FROM #LocalTempTable
)

SELECT Id, Name, RowNumber 
FROM tbl
WHERE RowNumber BETWEEN 1 AND 2;

drop table #LocalTempTable

CapsLock pressed C# example

C# > Controls > > IsKeyLocked

IsKeyLocked check if CAPS LOCK, NUM LOCK, or SCROLL LOCK key is are pressed.

Example:

public static bool CapsLockActive()

{
     return Control.IsKeyLocked(Keys.CapsLock);
}




 

What is ASP.NET

ASP.NET is a unified Web development model that includes the services necessary for you to build enterprise-class Web applications.

• System.Web

Get file name C# Example

C# > Files > GetFileName

Returns the file name and extension of the specified path string.

Example:

Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();

dlg.FileName = "Document";
dlg.DefaultExt = ".doc";
Nullable<bool> result = dlg.ShowDialog();
if (result == true)
{
     string filename = dlg.FileName;
     filename  = System.IO.Path.GetFileName(filename);
}