C# Generic Interface Example

C# > Generics > Generic Interface 

Example

class Serializer1 { public string Name { get; set; } };

class Serializer2 { public string Name { get; set; } };

interface GenericSerializer<T>

{

      string Name(T tValue);

}

class Serializer<T>: GenericSerializer<T>

{

public string Name(T tValue)

        {

            var prop = tValue.GetType().GetProperty("Name");

            return prop.GetValue(tValue, null) as string;

        }

}

Serializer1 s1 = new Serializer1() { Name = "Serializer1" };

Serializer2 s2 = new Serializer2() { Name = "Serializer2" };

Serializer<Serializer1> serializer1 = new Serializer<Serializer1>();

string name1 = serializer1.Name(s1);

Serializer<Serializer2> serializer2 = new Serializer<Serializer2>();

string name2 = serializer2.Name(s2);

LINQ Average excluding or including zeros c#

C# > LINQ > Average


Average computes the average of a sequence of numeric values.

Example

int[] int_array = new int[] { 5, 4, 2, 8, 10, 0 };

// linq average excluding zeros

double avg =

       (from ord in int_array

        where ord > 0

        select ord).Average();  // 5.8

// linq average including zeros 

avg =

       (from ord in int_array

       select ord).Average();    // 4.83

UPDATE SQL Server Example

SQL Server > DML > UPDATE

Changes existing data in a table or view.


Example

update

   person
set
   name = 'Bill'
where 
   id = 1

Reflection to find all classes implementing interface c#

C# > Reflection >  Find classes implementing interface

var iTtype = typeof(Interface);

var types = AppDomain.CurrentDomain.GetAssemblies()

           .SelectMany(a => a.GetTypes())

           .Where(t => iTtype.IsAssignableFrom(t));

Telerik GridViewCheckBoxColumn Alignment

Telerik > Windows Forms > RadGridView > GridViewCheckBoxColumn

GridViewCheckBoxColumn displays and allows editing of 

boolean data.

Example

GridViewCheckBoxColumn Alignment

<telerik:GridViewCheckBoxColumn DataMemberBinding="{Binding IsManager}" >

    <telerik:GridViewCheckBoxColumn.CellStyle>

        <Style TargetType="telerik:GridViewCell">

            <Setter Property="HorizontalContentAlignment" Value="Center" />

        </Style>

    </telerik:GridViewCheckBoxColumn.CellStyle>

</telerik:GridViewCheckBoxColumn>

Calculate SQL Server row size for a table

SQL Server > Scripts > Row Size

create table ##RowSize (tableName nvarchar(50), rowSize int)

exec sp_msforeachtable 'INSERT INTO ##RowSize Select ''?'' As tableName, SUM(c.Length) from dbo.SysColumns c where c.id = object_id(''?'') '

select * from ##RowSize order by rowSize  desc

drop table ##RowSize

Remove database SQL Server with sp_dbremove

SQL Server > System Stored Procedures > sp_dbremove

Removes a database.

Example

EXEC sp_dbremove HR;

Write, read XML to memory stream using XmlWriter and XmlReader C#

C# > XML > XmlWriter

XmlWriter  writes XML data to a file, stream,, text reader, or string.
It is fast, noncached and forward only.

Example
Write/read XML to memory stream.

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.IO;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;

using System.Xml;

namespace WindowsFormsApplication1

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        private void Form1_Load(object sender, EventArgs e)

        {

            MemoryStream stream = new MemoryStream();

            XmlWriter writer = XmlWriter.Create(stream);

            writer.WriteStartDocument();

            writer.WriteStartElement("Root");

            writer.WriteElementString("Child", "1");

            writer.WriteEndElement();

            writer.WriteEndDocument();

            writer.Flush();

            writer.Close();

            stream.Position = 0; // Resets the position to 0 so we can read.

            XmlReader reader = XmlReader.Create(stream);

            while (reader.Read())

            {

                //

            }

            reader.Close();

        }

    }

}

Select DataTable rows with where LINQ C#

C# > LINQ > Where

Where filters a sequence of values based on a predicate. 

Example

Select DataTable rows with where.

DataTable dt = new DataTable();

dt.Columns.Add("name", typeof(string));

dt.Rows.Add("john");

dt.Rows.Add("dan");

var filteredRows = dt.Rows

                  .Cast<DataRow>()

                  .Where(r => r["name"] == "dan").ToList();

Create new directory with DirectoryInfo C#

C# > Files > DirectoryInfo Class

Use this class for create, move and enumerating directories and subdirectories. 

Example 

Create new directory

DirectoryInfo directoryInfo = new DirectoryInfo(@"c:\Yourdir");

try

{

if (!directoryInfo.Exists)

       {

              directoryInfo.Create();

       }

}

catch (Exception ex)

{

MessageBox.Show("DirectoryInfo error: {0}", ex.ToString());

}

finally { }

Get Directory Size C#

C# > IO  > FileInfo > Length

Get the size of the file in bytes. 

Example

Get Directory Size C#

public long DirectorySize(DirectoryInfo dir)

{

       long size = 0;

       foreach (FileInfo file in dir.GetFiles())

       {

              size += file.Length;

       }

      foreach (DirectoryInfo directory in dir.GetDirectories())

       {

              size += DirectorySize(directory);

       }

       return size;

 }

DirectoryInfo dir = new DirectoryInfo(@"C:\Temp");

long size = DirectorySize(dir);

C# Capture Screen to PictureBox

C# > Drawing > Capture Screen

Bitmap printscreen = new Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height);

Graphics graphics = Graphics.FromImage(printscreen as Image);

graphics.CopyFromScreen(0, 0, 0, 0, printscreen.Size);

using (MemoryStream s = new MemoryStream())

{

printscreen.Save(s, System.Drawing.Imaging.ImageFormat.Bmp);

       picCapture.Size = new System.Drawing.Size(this.Width, this.Height);

       picCapture.Image = Image.FromStream(s);

}

XmlDocument C# Example

C# > XML > XmlDocument

Represents an XML document.

Example

XmlDocument doc = new XmlDocument();

doc.Load(xmlfile);

NetworkChange Class C#

C# > System.Net > NetworkInformation > NetworkChange

Use this class to receive notification when the IP address of a network interface changes.
Changes can appears when:

• disconnect network cable
• out of range of a wireless Local Area Network
• hardware failure

Events:

• NetworkAvailabilityChanged

C# NetworkInformation NameSpace

C# > System.Net > NetworkInformation

Provides access to network address information and traffic data.

Classes

• NetworkChange

ReadAllBytes C# Example

C# > Files > File Class > ReadAllBytes

Opens, reads the contents of the file into a byte array, and then closes the file.

Example

Read bytes from jpg file and display to PictureBox.

var bytes = File.ReadAllBytes("D:\\Pics\\1.jpg");

pictureBox1.Image = Image.FromStream(new System.IO.MemoryStream(bytes));

C# File Class

C# > Files > File Class

Use the File class for:

• copy, move, rename, create, open, delete to a single file at a time. 
• get and set file attributes.

All File methods are static.

Methods

• ReadAllBytes
• OpenText
• AppendText
• Move

IsNumeric equivalent in LINQ example

C# > LINQ > IsNumeric

IsNumeric equivalent in LINQ example.

double value;

var total = (from DataRow dr in dataTable.Rows

                where double.TryParse(dr["value"], out value)

                select Convert.ToDouble(dr["value"])).Sum();