1. C# Introduction
ISYS 350

2. Visual Studio 2015 Demo
Start page: New project/ Open project/Recent projects
Starting project:
File/New Project/
Visual C#
Windows
Windows form application
Project name/Project folder
Project windows:
Form design view/Form code view
Solution Explorer
View/Solution Explorer
ToolBox (visible while in form design view)
Property Window
Properties and Events
Server Explorer
Project/Add New Item
Property window example

3. Introduction to C# Event-driven programming
The interface for a C# program consists of one or more forms, containing one or more controls (screen objects).
Form and controls have events that can respond to. Typical events include clicking a mouse button, type a character on the keyboard, changing a value, etc.
Event procedure

4. Form Properties: Events:
Name, FormBorderStyle, Text, BackColor, BackImage, Opacity
Events:
Load, FormClosing, FormClosed
GotFocus, LostFocus
MouseHover, Click, DoubleCLick

5. Common Controls TextBox Label Button CheckBox RadioButton ListBox
ComboBox
PictureBox

6. Text Box
Properties:
BorderStyle, CauseValidation, Enabled, Locked, Multiline, PasswordChar, ReadOnly, ScrollBar, TabIndex, Text, Visible, WordWrap, etc.
Properties can be set at the design time or at the run time using code.
To refer to a property:
ControlName.PropertyName
Ex. TextBox1.Text
Note: The Text property is a string data type and automatically inherits the properties and methods of the string data type.

7. Typical C# Programming Tasks
Creating the GUI elements that make up the application’s user interface.
Visualize the application.
Make a list of the controls needed.
Setting the properties of the GUI elements
Writing procedures that respond to events and perform other operations.

8. To Add an Event-Procedure
1. Select the Properties window
2. Click Events button
3. Select the event and double-click it.
Note: Every control has a default event.
Form: Load event
Button control: Click event
Textbox: Text Changed event
To add the default event procedure, simply double-click the control.

9. Demo FirstName LastName .Control properties
Show Full Name
.Control properties
.Event: Click, MouseMove, Form Load, etc.
.Event procedures
FullName: textBox3.Text textBox3.Text = textBox1.Text + " " + textBox2.Text;
Demo: Text alignment (TextBox3.TextAlign=HorizontalAlign.Right)
TextBox3.BackColor=Color.Aqua;

10. Demo Num1 Num2 Compute Sum .Control properties
.Event: Click, MouseMove, Form Load, etc.
.Event procedures
Sum: textBox3.Text = (double.Parse(textBox1.Text) + double.Parse(textBox2.Text)).ToString();
In-Class lab: Show the product of Num1 and Num2.

11. C# Project’s Main Method
The execution starts from the Main method which is found in the Program.cs file.
Solution/Program.cs
Contain the startup code
Example: Application.Run(new Form1());

12. What does Variable mean?
A variable, in the context of programming, is a symbolic name given to an unknown quantity that permits the name to be used independent of the information it represents.
Variables are associated with data storage locations, and values of a variable are normally changed during the course of program execution.

13. Variable Names A variable name identifies a variable
Always choose a meaningful name for variables
Basic naming conventions are:
the first character must be a letter (upper or lowercase) or an underscore (_)
the name cannot contain spaces
do not use C# keywords or reserved words
Variable name is case sensitive

14. Declare a Variable
C# is a strongly typed language. This means that when a variable is defined we have to specify what type of data the variable will hold.
DataType VaraibleName;
A C# statement ends with “;”

15. string DataType string Variables: Examples: String concatenation: +
string empName;
string firstName, lastAddress, fullName;
String concatenation: +
fullName = firstName + lastName;
MessageBox.Show(“Total is “ );

16. Numeric Data Types int, double Examples:
double mydouble=12.7, rate=0.07;
int Counter = 0;
Other:
decimal: decimal myMoney = 300.5m;
float: float y = 4.5f;

17. Inputting and Outputting Numeric Values
Input collected from the keyboard are considered combinations of characters (or string literals) even if they look like a number to you
A TextBox control reads keyboard input, such as However, the TextBox treats it as a string, not a number.
In C#, use the following Parse methods to convert string to numeric data types
int.Parse
double.Parse
Examples:
int hoursWorked = int.Parse(hoursWorkedTextBox1.Text);
double temperature = double.Parse(temperatureTextBox.Text);
Note: We can also use the .Net’s Convert class methods: ToDouble, ToInt, ToDecimal.
Example: hoursWorked = Convert.ToDouble(textBox1.Text);

18. Explicit Conversion between Numeric Data Types with Cast Operators
C# allows you to explicitly convert among types, which is known as type casting
You can use the cast operator which is simply a pair of parentheses with the type keyword in it
int iNum1;
double dNum1 = 2.5;
iNum1 = (int) dNum1;
Note: We can also use the .Net’s Convert class methods

19. Implicit conversion and explicit conversion
int iNum1 = 5, iNum2 = 10;
double dNum1 = 2.5, dNum2 = 7.0;
dNum1 = iNum1 + iNum2; /*C# implicitly convert integer to double*/
iNum1 = (int) dNum1 * 2; /*from doulbe to integer requires cast operator*/

20. Performing Calculations
Basic calculations such as arithmetic calculation can be performed by math operators
Operator
Name of the operator
Description +
Addition
Adds two numbers -
Subtraction
Subtracts one number from another *
Multiplication
Multiplies one number by another /
Division
Divides one number by another and gives the quotient %
Modulus
Divides one number by another and gives the remainder
Other calculations: Use Math class’s methods.

21. Modulus Operator, %
Examples:
7%2
25%4

22. Example int dividend, divisor, quotient, remainder;
dividend = int.Parse(textBox1.Text);
divisor = int.Parse(textBox2.Text);
quotient = dividend / divisor;
remainder = dividend % divisor;
textBox3.Text = quotient.ToString();
textBox4.Text = remainder.ToString();
Note: The result of an integer divided by an integer is integer. For example, 7/2 is 3, not 3.5.

23. Lab Exercise
Enter length measured in inches in a textbox; then show the equivalent length measured in feet and inches.
For example, 27 inches is equivalent to 2 feet and 3 inches.

24. Change Machine to Return Smallest Number of Coins
int changes, quarters, dimes, nickles, pennies;
changes = int.Parse(textBox1.Text);
quarters = changes / 25;
dimes = (changes % 25) / 10;
nickles = (changes - quarters * 25 - dimes * 10) / 5;
pennies = changes - quarters * 25 - dimes * 10 - nickles * 5;
textBox2.Text = quarters.ToString();
textBox3.Text = dimes.ToString();
textBox4.Text = nickles.ToString();
textBox5.Text = pennies.ToString();

25. FV = PV * (1 +Rate) Year double pv, rate, years, fv;
pv = double.Parse(textBox1.Text);
rate = double.Parse(textBox2.Text);
years = double.Parse(textBox3.Text);
fv = pv*Math.Pow(1 + rate, years);
textBox4.Text = fv.ToString();

26. Formatting Numbers with the ToString Method
The ToString method can optionally format a number to appear in a specific way
The following table lists the “format strings” and how they work with sample outputs
Format String
Description
Number
ToString()
Result
“N” or “n”
Number format
12.3
ToString(“n3”)
12.300
“F” or “f”
Fixed-point scientific format
ToString("f2")
“E” or “e”
Exponential scientific format
ToString("e3")
1.235e+005
“C” or “c”
Currency format
ToString("C")
($1,234,567.80)
“P” or “p”
Percentage format
.234
ToString("P")
23.40%

27. Comments Line comment: // Block comment: /* …… */ // my comment
Comment n */