Difference between revisions of "OOP Class14"

Revision as of 19:36, 3 May 2006

Extra Stuff

File IO

write file

<csharp> string fileName = "test.txt";

           string folderPath = "c:\\user\\";  

           FileStream fs;

           //Make sure the the File exists if not create it if so open it
           if (!(File.Exists(folderPath + fileName)))
           {
               fs = File.Create(folderPath + fileName);
           }
           else
           {
               fs = new FileStream( folderPath + fileName , FileMode.Open, FileAccess.ReadWrite );
           }

           StreamWriter sw = new StreamWriter(fs);       //use streamwriter to write to file
        
           sw.Write("Hello World!!!");
           sw.Close();                                   //close writer
           fs.Close();                                   //close file stream</csharp>

http://iam.colum.edu/oop/gbrowser.php?file=/classsource/class14/hellowrite.cs

read file

<csharp> StreamReader sr = new StreamReader(fs);

           while( sr.Peek() > -1 )
           {
               Console.WriteLine(sr.ReadLine());
           }
           sr.Close();</csharp>

http://iam.colum.edu/oop/gbrowser.php?file=/classsource/class14/echoFile.cs

File Counter

http://iam.colum.edu/oop/classsource/class14/hitCounter.aspx [- source]

Send Mail

<csharp><% @Page Language="C#" %> <% @Import Namespace="System.Web.Mail" %> <%

   //set up some strings for the email
   
   string strTo = "only_a_test@fastmail.fm";
   string strFrom = "jeff@interactive.colum.edu";
   string strSubject = "Hi jeff";
   string strBody = "A real nice body text here";
   
   //Send email
   SmtpMail.SmtpServer = "localhost";
   SmtpMail.Send(strFrom, strTo, strSubject, strBody);

%></csharp> http://iam.colum.edu/oop/classsource/class14/mail.aspx [-source]

Upload a File

http uploader

Add executionTimeout and maxRequestLength to the web.config so that large uploads will not fail.

<xml> <configuration>

   <system.web>
       <httpRuntime
           executionTimeout="1200"
           maxRequestLength="65536"
       />
   </system.web>

</configuration> </xml>

multipart form <csharp> <form enctype="multipart/form-data" runat="server"> <tr>

 <td>Select file to upload:</td>
 <td>
 <input id="myfile" type="file" runat="server"></td>

</tr> <tr>

 <td>
 <input type=button id="btnUploadTheFile" value="Upload" 
       OnServerClick="btnUploadTheFile_Click" runat="server" />
 </td>

</tr> </form> </csharp>

Parse the multipart form and save the file msdn library. System.Web.HtmlInputFile.PostedFile Property

<csharp> void btnUploadTheFile_Click(object Source, EventArgs evArgs) {

   //Path to save file
   string strBaseLocation = "c:\\infod\\dangerdanger\\upload\\";
   
   if (null != myfile.PostedFile) 
   {
       // Get the HTTP posted file instance (to simplify the code) 
       HttpPostedFile postedfile = myfile.PostedFile; 
       
       // Get the filename 
       string filename = new System.IO.FileInfo(postedfile.FileName).Name; 
       string filesize = postedfile.ContentLength.ToString();
       try 
       {
           myfile.PostedFile.SaveAs(strBaseLocation+filename);
           txtOutput.InnerHtml = "File " + strBaseLocation + filename + " uploaded successfully";
       }
       catch (Exception e) 
       {
               txtOutput.InnerHtml = "Error saving " + strBaseLocation + filename + "

"+ e.ToString();

       }
       
       //Do some other stuff 
       //maybe  like send an email to let admin know file was uploaded
   }

} </csharp>

http://iam.colum.edu/oop/classsource/class14/up.aspx [up.aspx - source] [web.config - source]

Final Review

• Be very familar with c# syntax
  • Basic object types (int, bool, string)

• Understand Classes and inhertance.

• Use some advanced class features such as abstract classes and virual methods that are overridden

• Understand class relationships
  • Is A
  • Has A
  • Uses A

• Be able to read and create UML Diagrams