Debugging and Menus Part07dbg --- Solving the problem, Debugging in Break time, Menus, Common Dialogs, and User-written methods

2 Carefully Plan the Solution Understand the inputs and outputs of desired solution. Draw a sketch of proposed solution showing placement of controls. Assign meaningful names to controls using 3 character prefixes. Decide what variables (and appropriate scope) will be required. Choose test data and do hand/calculator calculations so that you know what answers should be produced by the program.

3 3 Modes of Operation Design Time --- before application is run Run Time --- when application is running Break Time --- when run time is suspended, for the purpose of debugging

4 Design Time Add controls to form via Designer. Set/review Property values for controls via Property Window. Add code to “handle” various events and set/change Property values (at runtime) via Code Window.

5 Run Time Code executed in event handler methods/functions can –change Property values for controls (Visible, ForeColor, BackColor, Text). –run methods to reset Focus(), Clear() contents, write variable/control values to the Output Window (via Debug.Writeline()) etc. –perform calculations/comparisons of variable values. –display variable values in controls. –handle various events.

6 How to Debug Code without using Break Time Trace through your program by hand, recording variable values (desk-checking). Insert statements into code that will print messages and/or values to the Output Window, so you see variable values, without preparing values for output in controls. System.Diagnostics.Debug.WriteLine(totRed); //print value of variable ---or--- using System.Diagnostics; //add at top of program Debug.WriteLine(totRed); //print value of variable ---or--- Console.WriteLine(totRed); //print value of variable

Using Visual Studio.NET Debugging Capabilities Using Break Time

8 Setting Break Points To set a breakpoint in your code, which will suspend execution before designated statement, –click in the light gray border to the left of the line of code. –press F9 –Debug, New Breakpoint in the menu

9 Helpful Windows during Break Time Code Window –Hover mouse over variable/control name to display its value. Locals Window –View values of local variables. –Class-level variables values can be viewed by clicking the + in front of this. Autos Window –Values of all variables in use near the highlighted line.

10 Stepping through Code Continue --- continue running (till next breakpoint) Step Into --- execute 1 statement Step Over --- execute 1 statement but don’t branch into any called method Step Out --- advance rapidly until reach end of function/method, then back to 1 statement at a time execution Restart --- start back at the beginning Stop Debugging

11 Removing Breakpoints To clear one breakpoint, position cursor and –click in gray border to left of designated line of code. –press F9. –choose Debug, Toggle Breakpoint from menu. To clear several breakpoints, choose Debug, Delete All Breakpoints from menu.

12 Let’s Try Debugging Together Get the zipped file, Ch04DebugCSR.zip, which is posted on the CIS205 course website in the Demonstration files section. This problem has error(s), which we will discover using the Debugging facilities of Visual Studio.NET.

Introduction to Menus MenuStrip and ContextMenuStrip

14 The MenuStrip Control The MenuStrip control can be used to add a menu to the top of a form. The MenuStrip control is new in VS.NET It replaces the MainMenu component in earlier versions of VS.NET. MainMenu components did not occupy the client area of the form. The client area of a form is the size of the form, minus the nonclient elements such as scroll bars, borders, and title bars. MenuStrip controls do occupy the client area of the form.

15 The Client Area The client area, defined by the ClientSize object and its Height and Width properties is that part of the form that can host controls. ClientSize.Width ClientSize.Height

16 MainMenu The icon for a MenuStrip control resides in the component tray area of the Designer. The MenuStrip control has a point and click editor for constructing a menu with MenuItems. MenuItems are essentially buttons that are contained in the Items collection associated with the MenuStrip control.

17 MenuItems MenuItems are added to a MenuStrip by typing the Text property of a MenuItem in a position suggested by the menu editor.

18 Renaming Menu Items MenuItems are controls and should be given meaningful names. A good organizational strategy is to use a compound name consisting of the menu (top line) name and the MenuItem name. Use the prefix mnu for MenuItems.

19 Coding Handlers for MenuItems The Click event is the default event for MenuItems and their handler functions may be created using the same techniques as with Buttons. We will add code to our MenuItem Click handler functions to assign different values to the BackColor property of the form.  SimpleMenu

20 Adding Menu Access () Keys Access (Hot) keys allow users to open menus and select menu items using the keyboard. Menus are opened by pressing Alt and the appropriate hot key. MenuItems are selected by simply pressing the hot key. Access (Hot) keys are created by inserting an & character ahead of the character (that will act as a hot key) in the Text property of a MenuItem.

21 Hot Keys at Run Time Hot keys appear underlined at run time. Hot keys in menus appear when the Alt key is pressed. Hot keys in open menus (MenuItems) appear automatically.  HotKeys

22 Menu Shortcuts Shortcuts allow selection of a menu item without even opening a menu. Shortcuts are assigned to function keys or control key combinations (e.g. ctrl + C). Shortcuts are applied to MenuItems by assigning a value to the Shortcut property of the MenuItem.

23 Menu Shortcuts An additional MenuItem property, ShowShortcuts, sets whether the shortcut will appear on the menu at run time. Curiously, shortcuts are never visible at design time. capture of shortcuts at run time  ShortCuts  InvisibleShortCuts

24 Menu Branching Branched menus are easily created by typing new MenuItem Text properties in the indicated positions. Naming conventions should recognize the node at which the menu branches.  BranchedMenu

25 Menu Separators Menu separators appear as simple horizontal lines to arrange menu items into groups. They are created by simply typing a hyphen for the Text Property of a MenuItem or right-clicking and choose Insert Separator.

26 ContextMenuStrips Rather than appear at the top of a form, ContextMenuStrips “pop up” when an object is right-clicked. Choose the ContextMenuStrip control from the Toolbox. Edit in the same way as a MenuStrip. Use cmu as the prefix for Context MenuItems Associate the ContextMenuStrip with a control by setting the ContextMenuStrip property of the control.  ContextMenus  ContextMenusDBG

27 Alternate Main Menus Multiple MenuStrip controls may be added to a form. To switch among the MenuStrips available: 1.assign the desired MenuStrip name to the MainMenuStrip property of the form. 2.set the Visible property of desired MenuStrip to true and the Visible property of undesired MenuStrip to false.  AlternateMainMenus

28 Using Common Dialog Boxes C# provides predefined standard dialog boxes for such tasks as specifying colors and fonts, and opening and saving. Use the common dialog controls in the Dialogs section of the Toolbox. When you double-click one of these dialogs, it will be added to the component tray below your form.

29 Common Dialog Objects Use the supplied object name (ex. FontDialog1). To change the font of lblOutput via FontDialog1, include the following code in the appropriate event handler: 1.Display the current property setting in the dialog. FontDialog1.Font = lblOutput.Font; //display current label font as selected font of dialog 2.Display the dialog FontDialog1.ShowDialog(); //display the dialog 3.After user makes a selection from dialog, assign user selection to the appropriate property. lblOutput.Font = FontDialog1.Font; //set label font to new user selected font

30 Let’s Do a Problem Together Make a copy of  WorkerWage complete and paste it into your CIS205 folder on the hard drive. Add the following menu structure to this existing problem: FileEditHelp Calculate Pay Clear About Summary Exit Font … Color …

31 Writing functions/methods So far the only functions/methods we have been working with are functions/methods that handle events; the skeleton of these functions/methods were typed for us when we double-clicked a control. You will recall from C++ or Java, that it is often convenient to write our own functions/methods: –To break a problem into smaller parts –Because some code will be executed in more than 1 place (reusable code) Before writing our own functions in C#, let’s review C++ and Java function/method syntax.

32 C++ Functions C++ functions consist of 2 parts: –Function prototype --- declares the function, specifies data type of returned value, lists number of parameters and their data types –Function definition --- function header (copy of prototype without ;) plus actual code to be executed These could be written within the source program file or contained in separate.cpp and.h files. Remember, a #include statement is necessary to incorporate the.h file when storing function definitions in separate files.

33 C++ Function Syntax Syntax: return-type functionName(data-type variable1, data-type variable2, …) Example 1: //function prototype double calcInterest (int y, double p, double r); //function definition double calcInterest(int y, double p, double r) { double temp; temp = p * r * y; return temp; } //function call in main() interest = calcInterest (years, principal, rate);

34 Another C++ Function Example Syntax: return-type functionName(data-type variable1, data-type variable2, …) Example2: //function prototype void printLoanInfo(int y, double p, double r, double i); //function definition void printLoanInfo(int y, double p, double r, double i) { cout << “You will have to pay $” << i << << “ interest on your loan of $” << p << “ for a term of ” << y << “ years at a rate of ” << r << “%.\n”; } //function call in main() printLoanInfo(years, principal, rate, interest);

35 Java Methods A Java method consists of just one part, the method definition. The method definition is made up of the method header and the actual code to be executed. No function/method prototype or import statements are required; just the function/method definition (without ;) is required.

36 Java Method Syntax Syntax: return-type functionName(data-type variable1, data-type variable2, …) Example 1: //method definition double calcInterest(int y, double p, double r) { double temp; temp = p * r * y; return temp; } //method call in main() interest = calcInterest (years, principal, rate);

37 Another Java Method Example Syntax: return-type functionName(data-type variable1, data-type variable2, …) Example2: //method definition void printLoanInfo(int y, double p, double r, double i) { System.out.println(“You will have to pay $” + i + “ interest on your loan of $” + p + “ for a term of ” + y + “ years at a rate of ” + r + “%.\n”; } //method call in main() printLoanInfo(years, principal, rate, interest);

38 C# Methods A C# method consists of just one part, the method definition. The method definition is made up of the method header and the actual code to be executed. No function/method prototype or using statements are required; just the function/method definition (without ;) is required.

39 C# Function/Method Syntax Syntax: private return-type functionName(data-type variable1, data-type variable2, …) Example 1: //method definition private decimal calcInterest(int y, decimal p, decimal r) { decimal temp; temp = p * r * y; return temp; } //method call interest = calcInterest(years, principal, rate);

40 C# Methods C# functions will generally have the keyword private as access modifier. –private indicates this function can only be used within this class (form) –public indicates this function can be used within other classes

41 Create a project to compute a checking account balance. Use radio buttons to choose the type of transaction (deposit, checking, or service charge). The user will enter the amount of transaction in a text box. Display the new balance in a label. Include validation that displays a message box if the amount of transaction is 0 or less. If there is not enough money to cover a check, display a message box with “Insufficient Funds”. Do not pay the check, but deduct a service charge of $10. Let’s Do a Problem Together

Write methods for processing deposits, checks, and service charges. The deposit method adds the deposit to the balance; the check method subtracts the check amount from the balance; the service charge method subtracts $10 from the balance. The Summary menu item displays the total number of deposits, the dollar amount of the deposits, the total number of checks, and the dollar amount of the checks in a message box. The Clear menu item clears the radio buttons and the amount and resets the focus. The Color and Font menu items change the color and the font of the information displayed in the balance label. Use a message box to display the program name and your name for the About menu item.