Compare Datetime Objects

Here i am going to share
1) How to Compare two Datetime object ( here i am mentioning some ways to Compare Datetime Variables )
2) How to get the timeSpan Values from the Hours and add hours to the Datetime its easy.

It can be expressed as a date and time of day.

It compares Date with time.

DateTime chkExpireDateTime = new DateTime(2009, 8, 1, 0, 0, 0);

if (DateTime.Compare(DateTime.Now , chkExpireDateTime)< 0)
{
// the Current Datetime.now is less than ChkExpireDateTime
}
else if (DateTime.Compare(DateTime.Now, chkExpireDateTime) > 0)
{
// the Current Datetime.now is Greater than ChkExpireDateTime
}
else if (DateTime.Compare(DateTime.Now, DateTime.Now) == 0)
{
// the Current Datetime.now and ChkExpireDateTime are Equal
}

You can also Compare this way.

DateTime systemDate = DateTime.Now;
DateTime compareDate = DateTime.Today.AddHours(11D);

// less than
if (compareDate < systemDate)
Console.WriteLine("Less Than");

// equal to
if (compareDate == systemDate)
Console.WriteLine("Equal To");

// greater than
if (compareDate > systemDate)
Console.WriteLine("Greater Than");

// basically you can compare it in all the normal ways
// using !=, ==, , =, etc



The below code is used to get the Timespan for the for the hours and minutes given through the string.

string time = "02:10";
string[] pieces = time.Split(new char[] { '.' },

StringSplitOptions.RemoveEmptyEntries);
TimeSpan difference2 = new TimeSpan(Convert.ToInt32(pieces[0]),

Convert.ToInt32(pieces[1]), 0);
double minutes2 = difference2.TotalMinutes; // 130
double totalSeconds = difference2.TotalSeconds; // 7800

// this will add the seconds to the Datetime

DateTime getOutTime = new DateTime();
getOutTime = DateTime.Now.AddHours(Convert.ToDouble (getHours ));
getOutTime = DateTime.Now.AddSeconds(totalSeconds);

Generate 16 Digit Unique Number in CSharp

Now i am going ot discuss about how to Generate 16 digit Unique number
So ,

5 digit Random using System.Random Class

5 digit number by using TimeSpan

6 numbers by System Time (HH:MM:SS)

This is the Code

System.Random fiveRandom = new Random();
TimeSpan tsFive = new TimeSpan();
tsFive = DateTime .Now.Subtract (Convert.ToDateTime ("01/01/1900"));
string rad = fiveRandom.Next(10000, 99999) + tsFive.Days.ToString() + System.DateTime.Now.Hour.ToString ("00") + System.DateTime.Now.Minute.ToString ("00") + System.DateTime.Now.Second.ToString ("00") ;

Difference between TypeOf and GetType

Here I am going to discuss about the - Difference between typeof and GetType ? - typeof and GetType produce the exact same information. But the difference is where they get this information from:

* typeof is used to get the type based on a class. That means if you use typeof with object, it will gives you error. You must pass class as parameter.
* Where GetType is used to get the type based on an object (an instance of a class). Means GetType needs parameter of object rather than class name.

You can understand more with example.

The following code will output “True”:

string instance = “”;

Type type1 = typeof(string);

Type type2 = instance.GetType();

Console.WriteLine(type1 == type2);

Extract the EmailID from the Text File

Here is the another article ie: which is going to find the emailID on the Text File and assign to a string.

Here i have the Textfile ie: Notepad File on the Server folder.

in the notepad file i have some content and emailID too, so i want to get the EmailID from the file so i have to send email to that user.

For this i am using REGEX so its easy to find the emailID on the text file and add or store it on arrays.

Here i am using the Two Method both are using REGEX pattern.


Here you go.. I tested - its working fine.

First Method:

using System.Text.RegularExpressions;
using System.IO;

try
{
//the file is in the root - you may need to change it
string filePath = MapPath("~") + "/EmailText.txt";

using (StreamReader sr = new StreamReader( filePath) )
{
string content = sr.ReadToEnd();
if (content.Length > 0)
{
//this pattern is taken from Asp.Net regular expression validators library
string pattern = @"\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*";
MatchCollection mc = Regex.Matches(content, pattern);
for (int i = 0; i < mc.Count; i++)
{
//here am just printing it.. You can send mails to mc[i].Value in thsi loop
Response.Write(mc[i].Value + "
");
}
}
}
}
catch (Exception ee)
{
Response.Write(ee.Message);
}

------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Second Method:

string pattern = @"[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?";

System.Text.RegularExpressions.Regex reg = new System.Text.RegularExpressions.Regex(pattern);

//Read file
string sFileContents =System.IO.File.ReadAllText(Server.MapPath("Email.txt"));

System.Text.RegularExpressions.MatchCollection mc = reg.Matches(sFileContents);

//string array for stroing
System.Collections.Generic.List str = new System.Collections.Generic.List();foreach (System.Text.RegularExpressions.Match m in mc)

{

str.Add(m.Value);

}

OUTPUT

input file
----------

jeevan@test.comjeevan@test.com This e-mail address is being protected from spambots. You need JavaScript enabled to view it ,

Welcome yo Hyderabadtechies.info
test@test.comtest@test.com This e-mail address is being protected from spambots. You need JavaScript enabled to view it ,
its really cool....

Chandrasekarthotta@gmail.comChandrasekarthotta@gmail.com This e-mail address is being protected from spambots. You need JavaScript enabled to view it

sdf

sdfs

dfsd



output :


jeevan@test.comjeevan@test.com This e-mail address is being protected from spambots. You need JavaScript enabled to view it , test@test.comtest@test.com This e-mail address is being protected from spambots. You need JavaScript enabled to view it , Chandrasekarthotta@gmail.comChandrasekarthotta@gmail.com

ASP.NET Performance Tips

Performance Improving Methods( From YSlow)
1. Make fewer HTTP requests
Decreasing the number of components on a page reduces the number of HTTP requests required to render the page, resulting in faster page loads. Some ways to reduce the number of components include: combine files, combine multiple scripts into one script, combine multiple CSS files into one style sheet, and use CSS Sprites and image maps.

2. Content Delivery Network (CDN)
User proximity to web servers impacts response times. Deploying content across multiple geographically dispersed servers helps users perceive that pages are loading faster.

3. Add Expires headers
Web pages are becoming increasingly complex with more scripts, style sheets, images, and Flash on them. A first-time visit to a page may require several HTTP requests to load all the components. By using Expires headers these components become cacheable, which avoids unnecessary HTTP requests on subsequent page views. Expires headers are most often associated with images, but they can and should be used on all page components including scripts, style sheets, and Flash.

4. Compress components with gzip
Compression reduces response times by reducing the size of the HTTP response. Gzip is the most popular and effective compression method currently available and generally reduces the response size by about 70%. Approximately 90% of today's Internet traffic travels through browsers that claim to support gzip.

5. Grade A on Put CSS at top
Moving style sheets to the document HEAD element helps pages appear to load quicker since this allows pages to render progressively.

6. Put JavaScript at bottom
JavaScript scripts block parallel downloads; that is, when a script is downloading, the browser will not start any other downloads. To help the page load faster, move scripts to the bottom of the page if they are deferrable.

7. Avoid CSS expressions
CSS expressions (supported in IE beginning with Version 5) are a powerful, and dangerous, way to dynamically set CSS properties. These expressions are evaluated frequently: when the page is rendered and resized, when the page is scrolled, and even when the user moves the mouse over the page. These frequent evaluations degrade the user experience.

8. Make JavaScript and CSS external
Using external JavaScript and CSS files generally produces faster pages because the files are cached by the browser. JavaScript and CSS that are inlined in HTML documents get downloaded each time the HTML document is requested. This reduces the number of HTTP requests but increases the HTML document size. On the other hand, if the JavaScript and CSS are in external files cached by the browser, the HTML document size is reduced without increasing the number of HTTP requests.

9. Reduce DNS lookups
The Domain Name System (DNS) maps hostnames to IP addresses, just like phonebooks map people's names to their phone numbers. When you type URL www.yahoo.com into the browser, the browser contacts a DNS resolver that returns the server's IP address. DNS has a cost; typically it takes 20 to 120 milliseconds for it to look up the IP address for a hostname. The browser cannot download anything from the host until the lookup completes.

10. Minify JavaScript and CSS
Minification removes unnecessary characters from a file to reduce its size, thereby improving load times. When a file is minified, comments and unneeded white space characters (space, newline, and tab) are removed. This improves response time since the size of the download files is reduced.

11. Avoid URL redirects
URL redirects are made using HTTP status codes 301 and 302. They tell the browser to go to another location. Inserting a redirect between the user and the final HTML document delays everything on the page since nothing on the page can be rendered and no components can be downloaded until the HTML document arrives.

12.Remove duplicate JavaScript and CSS
Duplicate JavaScript and CSS files hurt performance by creating unnecessary HTTP requests (IE only) and wasted JavaScript execution (IE and Firefox). In IE, if an external script is included twice and is not cacheable, it generates two HTTP requests during page loading. Even if the script is cacheable, extra HTTP requests occur when the user reloads the page. In both IE and Firefox, duplicate JavaScript scripts cause wasted time evaluating the same scripts more than once. This redundant script execution happens regardless of whether the script is cacheable.

12. Configure entity tags (ETags)
Entity tags (ETags) are a mechanism web servers and the browser use to determine whether a component in the browser's cache matches one on the origin server. Since ETags are typically constructed using attributes that make them unique to a specific server hosting a site, the tags will not match when a browser gets the original component from one server and later tries to validate that component on a different server.

13. Make AJAX cacheable
One of AJAX's benefits is it provides instantaneous feedback to the user because it requests information asynchronously from the backend web server. However, using AJAX does not guarantee the user will not wait for the asynchronous JavaScript and XML responses to return. Optimizing AJAX responses is important to improve performance, and making the responses cacheable is the best way to optimize them.

14. GET for AJAX requests
When using the XMLHttpRequest object, the browser implements POST in two steps: (1) send the headers, and (2) send the data. It is better to use GET instead of POST since GET sends the headers and the data together (unless there are many cookies). IE's maximum URL length is 2 KB, so if you are sending more than this amount of data you may not be able to use GET.

15. Reduce the number of DOM elements

A complex page means more bytes to download, and it also means slower DOM access in JavaScript. Reduce the number of DOM elements on the page to improve performance.
16. Avoid HTTP 404 (Not Found) error
Making an HTTP request and receiving a 404 (Not Found) error is expensive and degrades the user experience. Some sites have helpful 404 messages (for example, "Did you mean ...?"), which may assist the user, but server resources are still wasted.

17. Reduce cookie size
HTTP cookies are used for authentication, personalization, and other purposes. Cookie information is exchanged in the HTTP headers between web servers and the browser, so keeping the cookie size small minimizes the impact on response time.

18. Use cookie-free domains
When the browser requests a static image and sends cookies with the request, the server ignores the cookies. These cookies are unnecessary network traffic. To workaround this problem, make sure that static components are requested with cookie-free requests by creating a subdomain and hosting them there.


19. Avoid AlphaImageLoader filter
The IE-proprietary AlphaImageLoader filter attempts to fix a problem with semi-transparent true color PNG files in IE versions less than Version 7. However, this filter blocks rendering and freezes the browser while the image is being downloaded. Additionally, it increases memory consumption. The problem is further multiplied because it is applied per element, not per image.

20. Do not scale images in HTML
Web page designers sometimes set image dimensions by using the width and height attributes of the HTML image element. Avoid doing this since it can result in images being larger than needed. For example, if your page requires image myimg.jpg which has dimensions 240x720 but displays it with dimensions 120x360 using the width and height attributes, then the browser will download an image that is larger than necessary.

21. Make favicon small and cacheable
A favicon is an icon associated with a web page; this icon resides in the favicon.ico file in the server's root. Since the browser requests this file, it needs to be present; if it is missing, the browser returns a 404 error (see "Avoid HTTP 404 (Not Found) error" above). Since favicon.ico resides in the server's root, each time the browser requests this file, the cookies for the server's root are sent. Making the favicon small and reducing the cookie size for the server's root cookies improves performance for retrieving the favicon. Making favicon.ico cacheable avoids frequent requests for it.

what is overloading and overriding with example?

Overloading means two methods have the same method name and
different argument list.

For example, take the case of a Shape Class where you have
a method with the name DrawShape();
This method has two definitins with different parameters.

1. public void DrawShape(int x1, int y1,int x2,int y2)
{
// draw a rectangle.
}

2. public void DrawShape(int x1,int y1)
{

// draw aline.
}
overriding means i have a super class and sub class,sub
class extends the super class.Two classes containg the same
method name and same arguments sub class overides the super
class method ,this is nothing but method overriding
for example
Class Rectangle
{

publc void DrawRectangle()
{
// this method will draw a rectangle.
}

}


Class RoundRectangle : Rectanlge
{

public void DrawRectangle()
{

//Here the DrawRectangle() method is overridden in the
// derived class to draw a specific implementation to the
//derived class, i.e to draw a rectangle with rounded
corner.

}
}