Asp.net Examples » Uncategorized

Get Host by IP adress

anandnat — Mon, 06 Oct 2008 09:07:00 +0000

Get Host by IP adress

string IPAdress = “127.0.0.1″;
IPHostEntry IPHostEntryObject = Dns.GetHostEntry(IPAdress);
Console.WriteLine(IPHostEntryObject.HostName)

Posted in Uncategorized

Make C# Application Wait Amount of Time

anandnat — Mon, 06 Oct 2008 07:06:00 +0000

Stalling for Time

C#.Net programs sometimes need to wait a certain amount of time before carrying out the rest of the code. For example, an application that reminds users every 15 minutes to do something has to stall for 15 minutes.

While you can do time-measuring algorithms in C# with the Timer class, let’s try to use a simpler way…

DateTime vs StopWatch

If you remember the code speed test utility, there are two C# classes (not including Timer) that can measure time, the DateTime class and the System.Diagnostics.StopWatch class.

The DateTime class is good if you want to work with loose amounts of time, meaning that 14.98 seconds would be okay if you were aiming for 15.

The StopWatch class on the other hand is as precise as you can get with only C# code.

Whichever one you use is up to you…

How to Stall for Time

The basic way to stall for time in C# will be to use a while loop. In theory, we just need the loop to run in circles until enough time has passed. The example uses DateTime, but the StopWatch object would work too…

DateTime start = DateTime.Now;

while (DateTime.Now.Subtract(start).Seconds < 15)
{
}

That source code will work, but it is not elegant just yet. The problem is it freezes the C# program until the 15 seconds are over. Even worse, it eats up the CPU attention.

To keep the application responsive, you need to add the following C# line inside the loop:

Application.DoEvents();

That makes the applicaiton process its messages even while the loop is running. Thus normal UI interaction is kept running.

To prevent the CPU from going insane:

System.Threading.Thread.Sleep(1);

Technically that C# code can reduce how accurate the stalling time is, but giving the loop a 1 millisecond break per iteration, frees up the CPU.

Remember, both of those lines go inside the loop. And with that, you now have an elegant way to stall for time with simple C# code.

Posted in Uncategorized

Optimizing C# Application

anandnat — Mon, 06 Oct 2008 06:58:00 +0000

Optimizing C# Application

7 Ways To Optimize C# Code

Code optimization is an important aspect of writing an efficient C# application. The following tips will help you increase the speed and efficiency of your C# code and applications.

1. Knowing when to use StringBuilder

You must have heard before that a StringBuilder object is much faster at appending strings together than normal string types.

The thing is StringBuilder is faster mostly with big strings. This means if you have a loop that will add to a single string for many iterations then a StringBuilder class is definitely much faster than a string type.

However if you just want to append something to a string a single time then a StringBuilder class is overkill. A simple string type variable in this case improves on resources use and readability of the C# source code.

Simply choosing correctly between StringBuilder objects and string types you can optimize your code.

2. Comparing Non-Case-Sensitive Strings

In an application sometimes it is necessary to compare two string variables, ignoring the cases. The tempting and traditionally approach is to convert both strings to all lower case or all upper case and then compare them, like such:

str1.ToLower() == str2.ToLower()

However repetitively calling the function ToLower() is a bottleneck in performace. By instead using the built-in string.Compare() function you can increase the speed of your applications.

To check if two strings are equal ignoring case would look like this:

string.Compare(str1, str2, true) == 0 //Ignoring cases

The C# string.Compare function returns an integer that is equal to 0 when the two strings are equal.

3. Use string.Empty

This is not so much a performance improvement as it is a readability improvement, but it still counts as code optimization. Try to replace lines like:

if (str == "")

with:

if (str == string.Empty)

This is simply better programming practice and has no negative impact on performance.

Note, there is a popular practice that checking a string’s length to be 0 is faster than comparing it to an empty string. While that might have been true once it is no longer a significant performance improvement. Instead stick with string.Empty.

4. Replace ArrayList with List<>

ArrayList are useful when storing multiple types of objects within the same list. However if you are keeping the same type of variables in one ArrayList, you can gain a performance boost by using List<> objects instead.

Take the following ArrayList:

ArrayList intList = new ArrayList();
intList.add(10);
return (int)intList[0] + 20;

Notice it only contains intergers. Using the List<> class is a lot better. To convert it to a typed List, only the variable types need to be changed:

List<int> intList = new List<int>();

intList.add(10)

return intList[0] + 20;

There is no need to cast types with List<>. The performance increase can be especially significant with primitive data types like integers.

5. Use && and || operators

When building if statements, simply make sure to use the double-and notation (&&) and/or the double-or notation (||), (in Visual Basic they are AndAlso and OrElse).

If statements that use & and | must check every part of the statement and then apply the “and” or “or”. On the other hand, && and || go thourgh the statements one at a time and stop as soon as the condition has either been met or not met.

Executing less code is always a performace benefit but it also can avoid run-time errors, consider the following C# code:

if (object1 != null && object1.runMethod())

If object1 is null, with the && operator, object1.runMethod()will not execute. If the && operator is replaced with &, object1.runMethod() will run even if object1 is already known to be null, causing an exception.

6. Smart Try-Catch

Try-Catch statements are meant to catch exceptions that are beyond the programmers control, such as connecting to the web or a device for example. Using a try statement to keep code “simple” instead of using if statements to avoid error-prone calls makes code incredibly slower. Restructure your source code to require less try statements.

7. Replace Divisions

C# is relatively slow when it comes to division operations. One alternative is to replace divisions with a multiplication-shift operation to further optimize C#. The article explains in detail how to make the conversion.

Posted in Uncategorized

C# Unique Hardware ID

anandnat — Mon, 06 Oct 2008 06:55:00 +0000

C# Unique Hardware ID

Obtaining the Computer’s Unique ID

Each computer has certain hardware pieces that carry serial numbers. Using these serial numbers it is possible to obtain a hardware ID in C# that is unique to a certain computer only.

Keep in mind there are some serial numbers that are not true hardware serials, as in they change when the harddrive is formatted.

We are going to use the first CPU’s ID and the first Harddrive’s actual serial, neither of which change upon formatting. Using C# code, you can combine those serials into a unique hardware ID

Hardware IDs

Both ID’s will require the System.Management.dll reference. If you create a New Project the reference will not be added automatically.

Add it manually by right-clicking on “References” (in the Solution Explorer) and hit “Add Reference…”. Scroll down to System.Management (in the .Net tab) and add it…

CPU ID

Note that finding the CPU unique hardware ID is a bit different than normal C# programming. We’ll be accessing the property through string expressions rather than strong-typed properties.

string cpuInfo = string.Empty;
ManagementClass mc = new ManagementClass("win32_processor");
ManagementObjectCollection moc = mc.GetInstances();

foreach (ManagementObject mo in moc)
{
     if (cpuInfo == "")
     {
          //Get only the first CPU's ID
          cpuInfo = mo.Properties["processorID"].Value.ToString();
          break;
     }
}
return cpuInfo;

The function runs with a bit of a delay, but nothing too terrible.

Hard Drive ID (Volume Serial)

Finding a unique volume serial works very similarly and luckily a bit simplier:

ManagementObject dsk = new ManagementObject(@"win32_logicaldisk.deviceid=""" + drive + @":""");
dsk.Get();
string volumeSerial = dsk["VolumeSerialNumber"].ToString();

Deriving a Unique ID

The two serials can be combined in any way you wish. Use simple C# string functions or complex one. For example, after testing it across several systems, I decided to truncated serveral 0’s from the Volume Serial.

A quick note. What is the point of a unique hardware ID? The most common use for such information is for licensing software that is tailored to a specific computer of set of computers. With a bit of C# encryption functions, it can be an effective method.

Download the C# project files to see for yourself the speed of the combined functions and the complexity of the serial number...

Posted in Uncategorized

Upload a file only using browse button

anandnat — Wed, 24 Sep 2008 12:56:00 +0000

Posted in Uncategorized

Website ScreenShot ( Website Thumbnail)

anandnat — Wed, 17 Sep 2008 10:33:00 +0000

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Windows.Forms;
using System.Drawing;
using System.Drawing.Imaging;
using System.Threading;
using System.Windows.Forms;

public partial class snapshot : System.Web.UI.Page
{
   protected void Page_Load(object sender, EventArgs e)
   {
   string url = ((string.IsNullOrEmpty(Request.Params["site"])) ? “www.microsoft.com”:Request.Params["site"]);
   int width = ((string.IsNullOrEmpty(Request.Params["width"])) ? 200 : int.Parse(Request.Params["width"]));
   int height = ((string.IsNullOrEmpty(Request.Params["height"])) ? 140 : int.Parse(Request.Params["height"]));
   int capWidth = ((string.IsNullOrEmpty(Request.Params["capWidth"])) ? 1024 : int.Parse(Request.Params["capWidth"]));
   int capHeight = ((string.IsNullOrEmpty(Request.Params["capHeight"])) ? 768 : int.Parse(Request.Params["capHeight"]));
   bool fullHeight = ((string.IsNullOrEmpty(Request.Params["fullHeight"])) ? true : bool.Parse(Request.Params["fullHeight"]));

   string address = “http://” + url.Replace(“hhtp://”,”");
   Bitmap thumbnail = WebsiteThumbnailImageGenerator.GetWebSiteThumbnail(address, capWidth, capHeight, width, height,fullHeight);

   Response.ContentType = “image/jpeg”;
   thumbnail.Save (Response.OutputStream, ImageFormat.Jpeg);
   }
}

public class WebsiteThumbnailImageGenerator
{
   public static Bitmap GetWebSiteThumbnail(string Url, int BrowserWidth, int BrowserHeight, int ThumbnailWidth, int ThumbnailHeight, bool FullHeight)
   {
   WebsiteThumbnailImage thumbnailGenerator = new WebsiteThumbnailImage(Url, BrowserWidth, BrowserHeight, ThumbnailWidth, ThumbnailHeight,FullHeight);
   return thumbnailGenerator.GenerateWebSiteThumbnailImage();
   }

   private class WebsiteThumbnailImage
   {

   private WebBrowser _blankBrowser = null;

   public WebsiteThumbnailImage(string Url, int BrowserWidth, int BrowserHeight, int ThumbnailWidth, int ThumbnailHeight, bool FullHeight)
   {
   this.m_Url = Url;
   this.m_BrowserWidth = BrowserWidth;
   this.m_BrowserHeight = BrowserHeight;
   this.m_ThumbnailHeight = ThumbnailHeight;
   this.m_ThumbnailWidth = ThumbnailWidth;
   this.m_fullHeight = FullHeight;
   //_blankBrowser = new WebBrowser();
   }

   private string m_Url = null;
   public string Url
   {
   get
   {
   return m_Url;
   }
   set
   {
   m_Url = value;
   }
   }

   private Bitmap m_Bitmap = null;
   public Bitmap ThumbnailImage
   {
   get
   {
   return m_Bitmap;
   }
   }

   private int m_ThumbnailWidth;
   public int ThumbnailWidth
   {
   get
   {
   return m_ThumbnailWidth;
   }
   set
   {
   m_ThumbnailWidth = value;
   }
   }

   private int m_ThumbnailHeight;
   public int ThumbnailHeight
   {
   get
   {
   return m_ThumbnailHeight;
   }
   set
   {
   m_ThumbnailHeight = value;
   }
   }

   private int m_BrowserWidth;
   public int BrowserWidth
   {
   get
   {
   return m_BrowserWidth;
   }
   set
   {
   m_BrowserWidth = value;
   }
   }

   private int m_BrowserHeight;
   public int BrowserHeight
   {
   get
   {
   return m_BrowserHeight;
   }
   set
   {
   m_BrowserHeight = value;
   }
   }

private bool m_fullHeight;

public bool FullHeight
{
get { return m_fullHeight;}
set { m_fullHeight = value;}
}

   public Bitmap GenerateWebSiteThumbnailImage()
   {
   Thread m_thread = new Thread(new ThreadStart(_GenerateWebSiteThumbnailImage));
   m_thread.SetApartmentState(ApartmentState.STA);
   m_thread.Start();
   m_thread.Join();
   return m_Bitmap;
   }

   private void _GenerateWebSiteThumbnailImage()
   {
   WebBrowser m_WebBrowser = new WebBrowser();
   m_WebBrowser.ScrollBarsEnabled = false;
   m_WebBrowser.Navigate(m_Url);
   m_WebBrowser.DocumentCompleted += new WebBrowserDocumentCompletedEventHandler(WebBrowser_DocumentCompleted);
   while (m_WebBrowser.ReadyState != WebBrowserReadyState.Complete)
   Application.DoEvents();
   m_WebBrowser.Dispose();
   }

   private void WebBrowser_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
   {
   WebBrowser m_WebBrowser = (WebBrowser)sender;

   int _height = this.m_BrowserHeight;
   int _width = this.m_BrowserWidth;
   Size sz = m_WebBrowser.Size;

   if (this.FullHeight)
   {
   _height = m_WebBrowser.Document.Body.ScrollRectangle.Height;
   _width = m_WebBrowser.Document.Body.ScrollRectangle.Width;
   }
   if (_width < this.BrowserWidth)
   _width = this.BrowserWidth;

if (_height < sz.Height)
_height = sz.Height;

   if (_width != m_WebBrowser.Width)
   {
   m_WebBrowser.Size = new Size(_width, _height);
   //_blankBrowser.Size = new Size(_width, _height);
   m_WebBrowser.Refresh(WebBrowserRefreshOption.Completely);

   if (this.FullHeight)
   {
   _height = m_WebBrowser.Document.Body.ScrollRectangle.Height + SystemInformation.VerticalScrollBarWidth;
   }
   if (_height < sz.Height)
   _height = sz.Height;
   }

m_Bitmap = new Bitmap(_width, _height);
m_WebBrowser.DrawToBitmap(m_Bitmap, new Rectangle(m_WebBrowser.Location.X, m_WebBrowser.Location.Y, m_WebBrowser.Width, m_WebBrowser.Height));

   PrepareThumbNailSize(_height, _width);
   m_Bitmap = (Bitmap)m_Bitmap.GetThumbnailImage(m_ThumbnailWidth, m_ThumbnailHeight, null, IntPtr.Zero);
   }
   private void PrepareThumbNailSize(int OriginalHeight, int OriginalWidth)
   {

   if (this.FullHeight)
   {
   double factor = Convert.ToDouble(OriginalHeight) / Convert.ToDouble(OriginalWidth);
   double calc = Convert.ToDouble(this.m_ThumbnailWidth) * factor;
   int thumbHeight = Convert.ToInt32(calc);
   this.m_ThumbnailHeight = thumbHeight;
   }
   }
   }
}

Hello world!

anandnat — Sat, 19 Jul 2008 09:16:50 +0000

Welcome to WordPress.com. This is your first post. Edit or delete it and start blogging!

DHTML ToolTip with Calendar Control

anandnat — Tue, 25 Mar 2008 04:58:00 +0000

Introduction:

In one of my previous articles I talked about how you can effectively use DHTML with Asp.net to make cool tooltip. In this article I will show how you can use the same DHTML tooltip with the calendar control.

Getting Started:

The first thing you need to do is to download the DHTML script from www.dynamicdrive.com. You can download the script from this url http://www.dynamicdrive.com/dynamicindex5/dhtmltooltip.htm. After download the script just place the required css in the head section of the page and the script in the body of the page.

Screen shot of what we are going to do:

Here is a screen shot of what we are going to do in this article. As you can see that when you place your cursor over any date in the calendar it pops out the description in the DHTML box.

The Code:

The code is pretty simple. First you need to pull all the information from the database to your dataset or any other collection.

private DataSet GetArticles()

{

string connectionString = @”Server=localhost;Database=GridViewGuy;Trusted_Connection=true”;

SqlConnection myConnection = new SqlConnection(connectionString);

SqlDataAdapter ad = new SqlDataAdapter(“SELECT TOP 10 ArticleID,Title,Description,Abstract,DateCreated FROM Articles ORDER BY DateCreated DESC”, myConnection);

DataSet ds = new DataSet();

ad.Fill(ds, “Articles”);

return ds;

}

Next to display this information in the Calendar boxes you need to implement the Day_Render event of the Calendar Control.

protected void Calendar1_DayRender(object sender, DayRenderEventArgs e)

{

DataSet d = GetArticles();

foreach(DataRow dr in d.Tables[0].Rows) {

string dt = ((DateTime) dr["DateCreated"]).ToShortDateString();

if (dt == e.Day.Date.ToShortDateString())

{

e.Cell.Text = dr["Title"] as String;

}

string title = e.Cell.Text;

string ab = String.Empty;

foreach (DataRow dr in d.Tables[0].Rows)

{

if (title == dr["Title"] as String)

{

ab = dr["Abstract"] as String;

}

string dhtmlBox = “ddrivetip(‘” + ab + “‘,’lightyellow’,'200′)”;

e.Cell.Attributes["onmouseover"] = dhtmlBox;

e.Cell.Attributes["onmouseout"] = “this.style.backgroundColor=’#C0C000′;”;

}

All I am doing is I fill the Calendar cells using the e.Cell.Text property with the title of the article. And since I got everything I need thing I need in the dataset I simply browse the database for the particular description of the article and pops it up in the DTHML tooltip.