protected void ConvertButton_Click(object sender, EventArgs e)
{
int temp = 0;
//dont do anything unless a valid money amount has been entered in the money text box.
if (!money_text_box.Text.Equals("") && Int32.TryParse(money_text_box.Text, out temp))
{
// to declare that mywebService is webservice that we built which contains all the calculation logic
WebService1 mywebService = new WebService1();
// to invoke Curr_converter which is part of mywebService
// and provid it with 3 required inputs (currency_from,currency_to and amount of money to be converted)
TextBox1.Text = mywebService.Curr_converter(ddlfrom.SelectedValue, ddlto.SelectedValue, System.Convert.ToDecimal(money_text_box.Text));
// to show the exchange rate for both currencies
TextBox2.Text = "1 " + ddlfrom.SelectedValue + " = " + mywebService.get_rate_from_api(ddlfrom.SelectedValue, ddlto.SelectedValue) + " " + ddlto.SelectedValue;
TextBox3.Text = "1 " + ddlto.SelectedValue + " = " + mywebService.get_rate_from_api(ddlto.SelectedValue, ddlfrom.SelectedValue) + " " + ddlfrom.SelectedValue; ;
//make the result visible
TextBox1.Visible = true;
TextBox2.Visible = true;
TextBox3.Visible = true;
//only call the chart method if two different currencies has been entered, otherwise hide the chart
if (ddlto.SelectedIndex != ddlfrom.SelectedIndex) addChart(ddlfrom.SelectedValue, ddlto.SelectedValue);
else chart1.Visible = false;
}
else
{
//hide the textboxes if no valid amount has been entered
TextBox1.Visible = false;
TextBox2.Visible = false;
TextBox3.Visible = false;
}
}
private void addChart(string from, string to)
{
//clear all existing chart areas and series
chart1.Series.Clear();
chart1.ChartAreas.Clear();
//add new chart area and series for the new graph
chart1.Series.Add("Series1");
chart1.Series["Series1"].ChartType = SeriesChartType.Line;
chart1.ChartAreas.Add("ChartArea1");
//use web service to get the results to plot
WebService1 mywebService = new WebService1();
CurrencyElement[] result = mywebService.createChart(from, to);
//add each data point and label to the series
foreach (CurrencyElement obj in result)
{
DateTime date = (DateTime)obj.AxisX;
double rate = obj.AxisY;
chart1.Series["Series1"].Points.AddXY(date.Date, rate);
}
//adjust the appearance of the graph plot
chart1.ChartAreas["ChartArea1"].AxisX.Maximum = ((DateTime)result[result.GetLength(0) - 1].AxisX).ToOADate();
chart1.ChartAreas["ChartArea1"].AxisX.Minimum = ((DateTime)result[0].AxisX).ToOADate();
chart1.ChartAreas["ChartArea1"].AxisX.IntervalType = DateTimeIntervalType.Months;
chart1.ChartAreas["ChartArea1"].AxisX.Interval = 1;
//and add a titel to it
chart1.Titles.Add(
new Title(from + " to " + to + " currency changes over the past year",
Docking.Top,
new Font("Times New Roman", 12, FontStyle.Bold),
Color.Red)
);
//lastly make the graph visible for the user
chart1.Visible = true;
}