Weather Update application

• Download source files - 279 Kb
• Download demo project - 938 Kb

Introduction

This article is intended to show you how you can use the Internet to gather and display dynamic content.

Background

While teaching myself C#, I wanted to figure out how to use the HttpWebRequest and HttpWebResponse objects to gather information from the Internet. Being new to C#, I decided to rewrite one of my previous C++ applications in C#. What better way to learn the caveats of a new language than to rebuild an existing application in a newer language?

I’d like to thank Mike Gold from C# corner for his articles, Carlos Perez for his progress bar demo, Dion Heskett for his gradient label and Nishant S for his notify icon example. I’m an avid Code Project reader and appreciate all the hard work others have done.

The Code

string sfullpath = 
   @"http://asp.usatoday.com/weather/" + 
   @"cityforecast.aspx?LocationID=USVA0023&ps=L1";
                                             
HttpWebRequest MyWebReq;
HttpWebResponse MyWebRes;
StreamReader MySReader;
 

sForecast = "";
sTemp = "";
string sTempPrompt = @"font-size:20px"; 

// Get request & response from the internet.
MyWebReq = (HttpWebRequest) WebRequest.Create(sfullpath);
MyWebRes = (HttpWebResponse) MyWebReq.GetResponse();     
MySReader = new 
  StreamReader(MyWebRes.GetResponseStream(), Encoding.ASCII);

// Get the line of code the prompt is on.

while( sTemp.IndexOf( sTempPrompt ) == -1 )
{
    sTemp = MySReader.ReadLine();
}

MySReader .Close();
sTemp = sTemp.ToLower();
sTemp = sTemp.Trim();

sForecastOriginal = sTemp;

// Locate the index of the prompt.

int iTempIndex = sTemp.IndexOf( sTempPrompt );
iTempIndex = iTempIndex + 16;

sForecastOriginal = sForecastOriginal.Substring( iTempIndex, 600 );
sForecast = sForecastOriginal;

sTemp = sTemp.Substring( iTempIndex, 5 );
sTemp = sTemp.Substring( 0, sTemp.IndexOf( "<" ) );

// Trim string for displaying.
sTemp = sTemp.Trim();

//...

Using the code

The one main point I’d like to make is that since I’m parsing HTML, I’m at the mercy of the website where I’m getting the HTML from. If they decide to dramatically change the setup of their page, then this application might not get the correct data. If a message box pops up, shut the program down and then open it back up again. When the message box shows up, that means the HTML I'm trying to parse is being written.

History

Initial release 1.0.1