Convert distances TO and FROM (in. & ft.) using 2 listboxes.

Question

I am currently trying to do a practice program from the "Starting out with Visual C# 2012" textbook and I completed programming problems 1-4 but, I am stuck on number 5 "Distance Converter". The problem states that I have to create a program that allows the user to convert distances TO and From: Inches, Feet and Yards using 2 listboxes. ex. the user inputs a number and depending on which items are selected from each of the listboxes, will determine the output. Listbox1 has Inches, Feet, Yards Listbox2 has Inches, Feet, Yards *if the user inputs 50 and selects "Inches" from Listbox1 and selects "Feet" from Listbox2 then the output will show what 50 is, converted from inches to feet, etc.

Piyush Agarwal · Answer

Can you please share the screen shot of your UI to understand what you exactly need.

Nitin Sontakke · Answer

While there is possibly still a lot of scope for an improvement, the code posted by me is a good example of how you can ecapsulate logic in separate places. Implement abstraction, etc.

Nitin Sontakke · Answer

Here is a code you can use, after designing a form and after giving controls an appropriate names: using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; namespace WindowsFormsApp1 { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void Form1_Load( object sender, EventArgs e) { cboFrom.DataSource = Distances(); cboTo.DataSource = Distances(); } public List Distances() { List returnValue = new List (); returnValue.Add( "Inches" ); returnValue.Add( "Feet" ); returnValue.Add( "Yards" ); return returnValue; } private void comboBox1_SelectedIndexChanged( object sender, EventArgs e) { String strInput = txtInput.Text; if (String.IsNullOrEmpty(strInput)) return ; Double dblInput = 0; Boolean success = false ; success = Double.TryParse(strInput, out dblInput); if (!success) return ; Double output = GetConvertedValue(cboFrom.SelectedValue.ToString(), cboTo.SelectedValue.ToString(), dblInput); String message = String.Format( "{0} {1} is equal to {2} {3}" , new Object[] { dblInput, cboFrom.SelectedValue.ToString(), output, cboTo.SelectedValue.ToString() }); lblAnswer.Text = message; } private Double GetConvertedValue(String from, String to, Double input) { if (from == "Inches" && to == "Inches" ) return input; if (from == "Feet" && to == "Feet" ) return input; if (from == "Yards" && to == "Yards" ) return input; if (from == "Inches" && to == "Feet" ) return DistanceConverter.FromInchesToFeet(input); if (from == "Inches" && to == "Yards" ) return DistanceConverter.FromInchesToYards(input); if (from == "Feet" && to == "Inches" ) return DistanceConverter.FromFeetToInches(input); if (from == "Feet" && to == "Yards" ) return DistanceConverter.FromFeetToYards(input); if (from == "Yards" && to == "Inches" ) return DistanceConverter.FromYardToInches(input); if (from == "Yards" && to == "Feet" ) return DistanceConverter.FromYardToFeet(input); return input; } } public static class DistanceConverter { public static Double FromFeetToInches(Double value) { return value * 12; } public static Double FromInchesToFeet(Double value) { return value / 12; } public static Double FromYardToFeet(Double value) { return value * 3; } public static Double FromYardToInches(Double value) { return FromFeetToInches(FromYardToFeet(value)); } public static Double FromInchesToYards(Double value) { return FromInchesToFeet(FromFeetToYards(value)); } public static Double FromFeetToYards(Double value) { return value / 3; } } }

Nitin Sontakke · Answer

At precise which part you are stuck is not quite clear. Have you managed at least with trying to put together two list box and all essential UI and validation (you cannot have same selected in both list boxes, for example). If you have please share that code as an entire solution. Also find formulas and attempt to being implementation using classes.

Nitin Sontakke · Answer

Did you not have a look at the code I had posted?

A X · Answer

Hello and thank you for your help. I am currently reading the textbook because i am starting out with C#. I was having difficulty understanding how to process the operation if the user, (for example) selects inches from one listbox and yards from the second listbox or feet from the first listbox and inches from the second listbox, etc. I have created the forms design with: 1 textbox (for input) 2 listboxes (each containing Inches, feet, and yards) 1 label (for output) 1 button (to perform operation and display answer in label) i dont have much code because i do not understand how to process certain operations from both listboxes depending on what the user chooses. For example i know how to code the math operations i just dont know how to run the correct operation depending on what items the user chooses from each listbox. I thought about using switch statements but again i dont know how to include both listboxes. This is the code i have so far : *I apologize for not uploading my code before as i was on another computer . private void btnChange_Click( object sender, Event Args e) { int distance; //variable to store user input string option, option2; //variables to store items from each listbox if ( int .TryParse(textbox1.Text, out distance)) //to prevent exemption { if (listbox1.SelectedIndex != -1 && listbox2.SelectedIndex ! = -1) //to prevent exemption for listboxes { option = listbox1.SelectedItem.ToString(); option2 = listbox2.SelectedItem.ToString(); if (option == "Inches" && option2 == "Inches" ) { lblFinal.Text = Convert.ToString(distance); } else if (option == "Inches" && option2 == "Feet" ) { final = distance / 12; lblFinal.Text = Convert.ToString(final); } else if (option == "Feet" && option2 == "Feet" ) { lblFinal.Text = Convert.ToString(distance); } else if (option == "Feet" && option2 == "Inches" ) { final = distance * 12; lblFinal.Text = Convert.ToString(final); } } else { MessageBox.Show( "Please select an item from the list" ); } } else { Messagebox.Show( "Please enter a number!" ); } }}} //this is what i am trying to achieve. but it will not display anything in the lblChange.Text (because i am having trouble i only showed inches and feet. i decided not to include yards) should i create a SWITCH statement?