} //getSingleConversionRate
//Gets list of Currencies from the Database
public ArrayList getCurrencyNames()
{
ArrayList tempArray = new ArrayList();
try
{
string CommandString = "Select * from CurrencyConverter";
OleDbCommand cmd = new OleDbCommand(CommandString, MyConn);
OleDbDataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
CurrencyClass ccFrom = new CurrencyClass(reader["CurFromShort"].ToString(), reader["CurFromLong"].ToString());
CurrencyClass ccTo = new CurrencyClass(reader["CurToShort"].ToString(), reader["CurToLong"].ToString());
if (!tempArray.Contains(ccFrom))
{
tempArray.Add(ccFrom);
}//endif
if (!tempArray.Contains(ccTo))
{
tempArray.Add(ccTo);
} //endif
} //endwhile
} //endtry
catch { }
return(tempArray);
}//getCurrencyNames
public RateClass(CurrencyClass from, CurrencyClass to, double rate, DateTime dt)
{
ccFrom = from;
ccTo = to;
dblRate = rate;
dtDateTime = dt;
}//RateClass
}//getLongName
public override bool Equals(object o)
{
if (o == null || o.GetType() != typeof(CurrencyClass))
{
return(false);
}
CurrencyClass currency = (CurrencyClass)o;
return(currency.getLongName().Equals(this.strLongName) && currency.getShortName().Equals(this.strShortName));
}//Equals
}//WebParserClass
//This function will parse a web page and retrieve all currency names
public ArrayList getCurrencyNames()
{
//Regular expression to extract currency names from HTML
Regex regexOPTION = new Regex("</?\\w+\\s+\\w+=\"(.*)\">(.*)</\\w+>");
ArrayList tempArray = new ArrayList();
try
{
//get HTML from the site
WebRequest request = WebRequest.Create("https://www.google.com/finance/converter");
WebResponse response = request.GetResponse();
Stream data = response.GetResponseStream();
string html = String.Empty;
StreamReader reader = new StreamReader(data);
bool parse = false;
//read one line at a time untill criteria is met. Once met use regular expression to extract needed information
while (reader.Peek() >= 0)
{
html = reader.ReadLine();
if (html.Contains("select name=from"))
{
parse = true;
}//if
else if (html.Contains("</select>") && parse)
{
parse = false;
}//elseif
else if (parse)
{
Match matchOption = regexOPTION.Match(html);
CurrencyClass currency = new CurrencyClass(matchOption.Groups[1].Value, matchOption.Groups[2].Value);
tempArray.Add(currency);
} //elseif
} //while
} //try
catch { } //website not reachable
//If website parsing failed, fail over to Database
if (tempArray.Count == 0)
{
try
{
tempArray = clsDB.getCurrencyNames();
}
catch { }//Database not reachable
} //if
return(tempArray);
} //getCurrencyNames
//Method used for saving rates into the database
public bool saveRate(RateClass rate)
{
bool Successful = false;
CurrencyClass ccFrom = rate.getFrom();
CurrencyClass ccTo = rate.getTo();
//If entry does not exist insert it
if (checkForDuplicate(rate) == false)
{
try
{
string insert = "INSERT INTO CurrencyConverter ([CurFromLong], [CurFromShort], [CurToLong], [CurToShort], [Rate], [DateTime]) VALUES (@CurFromLong, @CurFromShort, @CurToLong, @CurToShort, @Rate, @DateTime);";
OleDbCommand cmd = new OleDbCommand(insert, MyConn);
cmd.Parameters.AddWithValue("@CurFromLong", ccFrom.getLongName());
cmd.Parameters.AddWithValue("@CurFromShort", ccFrom.getShortName());
cmd.Parameters.AddWithValue("@CurToLong", ccTo.getLongName());
cmd.Parameters.AddWithValue("@CurToShort", ccTo.getShortName());
cmd.Parameters.AddWithValue("@Rate", rate.getRate().ToString());
cmd.Parameters.AddWithValue("@DateTime", rate.getTimeDate().ToString());
cmd.ExecuteNonQuery();
Successful = true;
} //endtry
catch {}
} //endif
//if entry does exist, update it
else
{
try
{
string update = "UPDATE CurrencyConverter SET [Rate]=@Rate, [DateTime]=@DateTime WHERE CurFromShort LIKE '" + ccFrom.getShortName() + "' AND CurToShort LIKE '" + ccTo.getShortName() + "'";
OleDbCommand cmd = new OleDbCommand(update, MyConn);
cmd.Parameters.AddWithValue("@Rate", rate.getRate().ToString());
cmd.Parameters.AddWithValue("@DateTime", rate.getTimeDate().ToString());
cmd.ExecuteNonQuery();
Successful = true;
}//endtry
catch
{
//returns false
} //endcatch
} //endelse
return(Successful);
} //Saverate
} //threadAllConversionRates
public RateClass getSingleConversionRate(CurrencyClass ccFrom, CurrencyClass ccTo, bool useDB)
{
RateClass rate = null;
try
{
//Regular expression to extract conversion rate from HTML
Regex regexRate = new Regex("bld>([0-9]*\\.?[0-9]*)");
WebRequest request = WebRequest.Create("https://www.google.com/finance/converter?a=1&from=" + ccFrom.getShortName() + "&to=" + ccTo.getShortName());
WebResponse response = request.GetResponse();
Stream data = response.GetResponseStream();
string html = String.Empty;
StreamReader reader = new StreamReader(data);
//Read one line of HTML at a time until criteria is met then extract rate
while (reader.Peek() >= 0)
{
html = reader.ReadLine();
if (html.Contains("span class=bld"))
{
Match matchRate = regexRate.Match(html);
if (matchRate.Success)
{
Debug.WriteLine("Rate from " + ccFrom.getShortName() + " to " + ccTo.getShortName() + " is " + matchRate.Groups[1].Value);
rate = new RateClass(ccFrom, ccTo, Convert.ToDouble(matchRate.Groups[1].Value), DateTime.Now);
} //if
} //if
} //while
} //try
catch { } //website not reachable
if (useDB)
{
if (rate == null)
{
rate = clsDB.getSingleConversionRate(ccFrom, ccTo);
}//if
else
{
clsDB.saveRate(rate);
} //else
} //if
return(rate);
} //getSingleConversionRate
} //OpenDatabaseConnection
//Checks to see if provided entry already exists in the Database
private bool checkForDuplicate(RateClass rate)
{
try
{
CurrencyClass ccFrom = rate.getFrom();
CurrencyClass ccTo = rate.getTo();
string CommandString = "Select * from CurrencyConverter where CurFromShort like '" + ccFrom.getShortName() + "' and CurToShort like '" + ccTo.getShortName() + "'";
OleDbCommand cmd = new OleDbCommand(CommandString, MyConn);
OleDbDataReader reader = cmd.ExecuteReader();
if (reader.HasRows)
{
return(true);
}
else
{
return(false);
}
}
catch
{
return(false);
}
} //checkForDuplicate
} //Saverate
//Gets single conversion rate from the database
public RateClass getSingleConversionRate(CurrencyClass ccFrom, CurrencyClass ccTo)
{
RateClass rate = null;
string CommandString = "Select * from CurrencyConverter where CurFromShort like '" + ccFrom.getShortName() + "' and CurToShort like '" + ccTo.getShortName() + "'";
OleDbCommand cmd = new OleDbCommand(CommandString, MyConn);
OleDbDataReader reader = cmd.ExecuteReader();
if (reader.RecordsAffected > 1)
{
//more then one record was returned
}//endif
else
{
double rateVal = 0;
DateTime dateAdded = DateTime.Now;
while (reader.Read())
{
rateVal = Convert.ToDouble(reader["Rate"].ToString());
dateAdded = Convert.ToDateTime(reader["DateTime"].ToString());
} //emdwhile
rate = new RateClass(ccFrom, ccTo, rateVal, dateAdded);
} //endelse
return(rate);
} //getSingleConversionRate
} //frmMain_Load
//Converts currencies when the button is clicked
private void btnConvert_Click(object sender, EventArgs e)
{
if (cmbFrom.SelectedItem == cmbTo.SelectedItem)
{
txtTo.Text = txtFrom.Text;
lblAsOf.Text = "As Of " + DateTime.Now;
}//if
else
{
CurrencyClass ccFrom = new CurrencyClass((string)((ComboboxItem)cmbFrom.SelectedItem).Value, ((ComboboxItem)cmbFrom.SelectedItem).Text);
CurrencyClass ccTo = new CurrencyClass((string)((ComboboxItem)cmbTo.SelectedItem).Value, ((ComboboxItem)cmbTo.SelectedItem).Text);
RateClass rate = webParser.getSingleConversionRate(ccFrom, ccTo, true);
Debug.WriteLine(rate.ToString());
if (rate != null)
{
txtTo.Text = "" + (Convert.ToDouble(txtFrom.Text) * rate.getRate());
lblAsOf.Text = "As Of " + rate.getTimeDate().ToString();
}//if
else
{
MessageBox.Show("Could not retrieve conversion rate for " + ccFrom.getShortName() + " to " + ccTo.getShortName() + " at this time!", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
} //else
} //else
} //btnConvert_Click
