This will give treeview of all drives on hard disk

foreach (System.IO.DriveInfo drive in System.IO.DriveInfo.GetDrives())
{
TreeNode node = new TreeNode();
node.Value = drive.Name;
//Make sure the drive is ready before we access it
if (drive.IsReady)
{
node.Text = drive.Name + " - (free space: " + drive.AvailableFreeSpace + ")";
this.TreeView1.Nodes.Add(node);
}
else
{
node.Text = drive.Name + " - (not ready)";
this.TreeView1.Nodes.Add(node);
}
}

This will give all information about c:\

System.IO.DriveInfo Drive = new System.IO.DriveInfo(@"c:\");
lblDriveName.Text = Drive.Name;
lblDriveType.Text = Drive.DriveType.ToString();
lblAvailableFreeSpace.Text = Drive.AvailableFreeSpace.ToString();
lblDriveFormat.Text = Drive.DriveFormat;
lblTotalFreeSpace.Text = Drive.TotalFreeSpace.ToString();
lblTotalSize.Text = Drive.TotalSize.ToString();
lblVolumeLabel.Text = Drive.VolumeLabel;

Hto dynamically set IsReadonly property of the File to false

string download_filename = (Server.MapPath("aatish.txt"));

System.IO.FileInfo fileInfo = new System.IO.FileInfo(download_filename);

fileInfo.IsReadOnly = false;

How to create webservice ?

1) create file with .asmx file

2) write your logic in .cs file for example

using System;
using System.Collections;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Xml.Linq;
using System.Data;
using System.Data.SqlClient;

///

/// Summary description for WebService_360
///

[WebService(Namespace = "http://aatish.com/WebService_360", Name = "GetCustomers")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line.
// [System.Web.Script.Services.ScriptService]
public class WebService_360 : System.Web.Services.WebService {

public WebService_360 () {

//Uncomment the following line if using designed components
//InitializeComponent();
}

[WebMethod]
public DataSet GetCustomers()
{
SqlConnection conn;
SqlDataAdapter myDataAdapter;
DataSet myDataSet;
string cmdString = ("select * from student_info");
conn = new SqlConnection("Server=myserver;database=allexample;Integrated Security=SSPI;");
myDataAdapter = new SqlDataAdapter(cmdString, conn);
myDataSet = new DataSet();
myDataAdapter.Fill(myDataSet, "student_info");
return myDataSet;
}
}

3) Add ref to web service through

add web references

4) call web service

protected void Button1_Click(object sender, EventArgs e)
{
try
{
myservices.customer mycustomer = new myservices.customer();
GridView1.DataSource = mycustomer.getcustomer();
GridView1.DataBind();
}
catch (Exception ex)
{
Response.Write(ex.Message);
}

}

How to use 3 tier architecture ?

1) create App_code folder
2) In App_code folder create BLL folder and again In BLL folder create BLL.CS file
3) In App_code folder create DAL folder and again In DAL folder create DAL.CS file
4) IN every BLL and DLL class file create private,public regions for variables and methods.

FOR EXAMPLE BLL.cs

using System;
using System.Data;
using System.Configuration;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

///

/// Summary description for BLL
///

public class BLL
{
public BLL()
{
//
// TODO: Add constructor logic here
//
}
#region Private Variables

DateTime _date;

#endregion

#region Public Properties

public DateTime DATE
{
set { _date = value; }
get { return _date; }
}

#endregion


#region Public Methods

public DataSet GetUserInfo()
{
DataSet ds = new DataSet();
try
{
ds = DAL.GetUserInfo(this);
return ds;
}
catch(Exception ex)
{
ex=ex;
return ds;
}
}

FOR EXAMPLE DAL.cs

using System;
using System.Data;
using System.Configuration;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using LCE.DAL;
using System.Data.SqlClient;
///

/// Summary description for DAL
///

public class DAL
{
public DAL()
{
//
// TODO: Add constructor logic here
//
}
#region Private Variables
#endregion
#region Public Properties
#endregion
#region Public Methods

public static DataSet GetUserInfo(BLL objUser)
{
DataSet ds = new DataSet();
try
{
ds = (SqlHelper.ExecuteDataset(LCE.Configuration.GetConnectionString(), CommandType.StoredProcedure,

"spGetUserInfo"));
return ds;
}
catch(Exception ex)
{
ex = ex;
return ds;
}
}

How to make connection on page.

How to make connection on page.
SqlConnection conn = new SqlConnection ("server=360-2009-09; database=all example; Integrated Security=SSPI ;");
SqlCommand cmd;
SqlDataAdapter da;
SqlDataReader dr;
DataSet ds = new DataSet ();

ON Page Load
con.Open ();
da =new SqlDataAdapter("select * from New_user",con);
DataSet ds = new DataSet();
da.Fill (ds,"New_user");
datagrid1.DataSource=ds;
datagrid1.DataBind ();
con.Close ();

OR (SELECT)
cmd = new SqlCommand("select * from user_info where userid=@userid", conn);
int myvalue = Convert.ToInt16(GridView1.SelectedRow);
cmd.Parameters.Add("userid",GridView1.SelectedValue);
dr = cmd.ExecuteReader();
dr.Read();
while(dr.Read())
{
assign values to diffrent control.
}
dr.Close();
conn.Close();
OR(INSERT)

cmd = new SqlCommand("insert into New_user values('" +txtfname.Text + "','" + txtlastname.Text + "')", con);
con.Open();
cmd.ExecuteNonQuery();
con.Close();

OR(UPDATE)

cmd = new SqlCommand("update user_info set firstname=@firstname,lastname=@lastname where userid=@userid", conn);
cmd.Parameters.Add("userid", txtuid.Text);
cmd.Parameters.Add("firstname",txtfname.Text);
cmd.Parameters.Add("lastname",txtlname.Text);
statuslabel.Text = "Your record updated successfully...";
conn.Open();
cmd.ExecuteNonQuery();
conn.Close();

How to make connection on page.

SqlConnection conn = new SqlConnection("server=myserver;database=allexample;Integrated Security=SSPI;");
SqlCommand cmd;
SqlDataAdapter da;
SqlDataReader dr;
DataSet ds = new DataSet();


ON Page Load

con.Open();
da =new SqlDataAdapter("select * from New_user",con);
DataSet ds = new DataSet();
da.Fill(ds,"New_user");
datagrid1.DataSource=ds;
datagrid1.DataBind();
con.Close();


OR (SELECT)

cmd = new SqlCommand("select * from user_info where userid=@userid", conn);
int myvalue = Convert.ToInt16(GridView1.SelectedRow);
cmd.Parameters.Add("userid",GridView1.SelectedValue);
dr = cmd.ExecuteReader();
dr.Read();
while(dr.Read())
{
assign values to diffrent control.
}
dr.Close();
conn.Close();


OR(INSERT)

cmd = new SqlCommand("insert into New_user values('" +txtfname.Text + "','" + txtlastname.Text + "')", con);
con.Open();
cmd.ExecuteNonQuery();
con.Close();

OR(UPDATE)

cmd = new SqlCommand("update user_info set firstname=@firstname,lastname=@lastname where userid=@userid", conn);
cmd.Parameters.Add("userid", txtuid.Text);
cmd.Parameters.Add("firstname",txtfname.Text);
cmd.Parameters.Add("lastname",txtlname.Text);
statuslabel.Text = "Your record updated successfully...";
conn.Open();
cmd.ExecuteNonQuery();
conn.Close();