Private assembly is used inside an application only and does not have to be identified by a strong name. Shared assembly can be used by multiple applications and has to have a strong name.

A strong name includes the name of the assembly, version number, culture identity, and a public key token.

Delay signing allows you to place a shared assembly in the GAC by signing the assembly with just the public key. This allows the assembly to be signed with the private key at a later stage, when the development process is complete and the component or assembly is ready to be deployed. This process enables developers to work with shared assemblies as if they were strongly named, and it secures the private key of the signature from being accessed at different stages of development.

Help of Strong Name tool (sn.exe).

contains thousands of classes organized logically through a namespaces. You can add these classes in your web or Windows application where needed to reduce developing time

It looks same. We can use Debug class for debug builds snd Trace class for both debug and release builds.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Excel = Microsoft.Office.Interop.Excel;

namespace excel2
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click_1(object sender, EventArgs e)
{
Excel.Application xlApp;
Excel.Workbook xlWorkBook;
Excel.Worksheet xlWorkSheet;
object misValue = System.Reflection.Missing.Value;

xlApp = new Excel.Application();
xlWorkBook = xlApp.Workbooks.Add(misValue);
xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);

xlWorkSheet.SetBackgroundPicture(@"C:\Users\snair02\Desktop\SRJ DOCS\a.jpg");

//add some text
xlWorkSheet.Cells[1, 1] = "http://csharp.net-informations.com";
xlWorkSheet.Cells[2, 1] = "Adding background in Excel File";


xlWorkBook.SaveAs("csharp.net-informations.xls", Excel.XlFileFormat.xlWorkbookNormal, misValue, misValue, misValue, misValue, Excel.XlSaveAsAccessMode.xlExclusive, misValue, misValue, misValue, misValue, misValue);
xlWorkBook.Close(true, misValue, misValue);
xlApp.Quit();

releaseObject(xlApp);
releaseObject(xlWorkBook);
releaseObject(xlWorkSheet);

MessageBox.Show("File created !");
}

private void releaseObject(object obj)
{
try
{
System.Runtime.InteropServices.Marshal.ReleaseComObject(obj);
obj = null;
}
catch (Exception ex)
{
obj = null;
MessageBox.Show("Unable to release the Object " + ex.ToString());
}
finally
{
GC.Collect();
}

}



}




}

The is one of the coolest property that Microsoft had come up in ASP.Net 2.0 where by using this we can maintain the scroll position of page in post backs.

Yes, using the params keyword.

The throw keyword is used to throw an exception programatically in C#.