Solution – ChallengeConditionalRadioButton

This is the Solution for the Challenge titled ChallengeConditionalRadioButton. As always, read only as much as you need to solve the specific issue you’re having, but try to solve the rest on your own. Struggling with concepts is part of learning, and overcoming these challenges will give you an advantage down the road in this course.

Step 1: Add the Server Controls

By now you should be familiar with creating a Project and your Default.aspx page, so create those as we have been in the lessons. Switch to the Design view in Visual Studio to begin adding Server Controls to your form. You’ll need to style your form as shown below, with four RadioButtons, a Button and a Label:

Next, change the programmatic ID’s of each of the Server Controls to the following:

1. pencilRadioButton
2. penRadioButton
3. phoneRadioButton
4. tabletRadioButton
5. okButton
6. resultLabel

Step 2: Working with the okButton_Click

Once all of this is set up as shown, double-click on the okButton to generate an EventHandler for when the okButton is clicked. Inside this code block, write if() and else if() statements to check which RadioButton is selected:

Note: While you could create each individual if() and else if() statement in its entirety before creating the next, creating all of them at the same time will allow you to copy and paste the code for your conditional into the next.

Inside the first if() statement, set the resultLabel’s Text property to "You selected Pencil". Copy and paste this code into each of the else if() statements:

Now, simply change the word Pencil in the literal string to the appropriate RadioButton. i.e. Pen for penRadioButton. Finally, add an else() statement in the event that the user doesn’t select a RadioButton at all. Inside the else(), set the resultLabel’s Text to "Please select an option". Your code should look like this:

Now, save and run your code to test the Project. You’ll notice that the program runs as intended if you select a RadioButton, but it allows multiple RadioButtons to be selected at the same time.

Step 3: RadioButton Groups

To fix this, go back to the Default.aspx page and select the pencilRadioButton. In the Properties window, under Behavior, you will find the GroupName property. Set this property to NoteGroup for all the RadioButtons. This will force their selection to be mutually exclusive so that only one condition can be true at a time.

Save and run your Project again. This time, you will find that the resultLabel displays the appropriate value for the selection, and only one RadioButton can be selected at a time.

Bonus: Image Control

This bonus challenge deals with a Server Control we have not discussed yet: Image. What you need to do is display one of four images provided in the code folder for this Challenge depending on what the user’s selection was.

To begin with, open up the code folder for this lesson and drag the four images under the "Assets" section into your Project:

Next, add a space underneath your okButton and insert the Image Server Control by double-clicking it. Change its programmatic ID to ‘resultImage’. You’ll also see in the Properties window for the Image, under Appearance, there is a property called ImageUrl:

While the Properties window allows you to manually set the ImageUrl, this Challenge requires you to change it at runtime. In order to do this, go back into the okButton_Click Event. Copy and paste the if() and else if() statements, then comment out the originals. Clear out the resultLabel code in each of the if() and else if() statements you just pasted, with the exception of the else():

In the if() statement for the pencilRadioButton, add a line that says, ‘resultImage.ImageUrl = "pencil.png" ‘ Note the quotation marks around "pencil.png", this is necessary in order to reference the file you added to your Project. Repeat this step for each of the else if() statements, selecting the appropriate ImageUrl for each:

Save and run your Project to see the result:

Conclusion

Congratulations on completing the ChallengeConditionalRadioButton! If you had trouble, I encourage you to revisit this Challenge and try again. Keep trying until this becomes second nature to you, as repetition will reinforce what you are learning. You’re doing a great job so far, keep it up!

• GETTING STARTED
  • Lesson 1 – Series Introduction
  • Lesson 2 – Installing Visual Studio 2015
  • Lesson 3 – Building Your First Web App
  • Lesson 4 – Understanding What You Just Did
  • Lesson 5 – Working With Projects In Visual Studio
  • Lesson 6 – Simple Web Page Formatting In Visual Studio
  • Challenge 1
    • Solution 1
• DATA TYPES, VARIABLES, OPERATORS
  • Lesson 7 – Variables and Data Types
  • Lesson 8 – Data Type Conversion
  • Lesson 9 – Arithmetic Operators
  • Lesson 10 – C# Syntax Basics
  • Challenge 2 ChallengeSimpleCalculator
    • Solution 2 ChallengeSimpleCalculator
• BRANCHING LOGIC, COMPARISON OPERATORS
  • Lesson 11 – Conditional If Statements
  • Lesson 12 – The Conditional Ternary Operator
  • Lesson 13 – Comparison and Logical Operators
  • Challenge 3 ChallengeConditionalRadioButton
    • Solution 3 ChallengeConditionalRadioButton
  • Lesson 13 Challenge Papa Bob’s Pizza Website
  • Solution Papa Bob’s Pizza Website
• DATETIME, TIMESPAN, CALENDAR
  • Lesson 14 – Working with Dates and Times
  • Lesson 15 – Working with Spans of Time
  • Lesson 16 – Working with the Calendar Server Control
  • Challenge 4 ChallengeDaysBetweenDates
    • Solution 4 ChallengeDaysBetweenDates
• ASP.NET, STRING FORMATTING
  • Lesson 17 – Page_Load and Page.IsPostBack
  • Lesson 18 – Setting a Break Point and Debugging
  • Lesson 19 – Formatting Strings
  • Challenge 5 ChallengeEpicSpiesAssignment
    • Solution 5 ChallengeEpicSpiesAssignment
  • Lesson 20 – Maintaining State with ViewState
• ARRAYS, ITERATION STATEMENTS
  • Lesson 21 – Storing Values in Arrays
  • Lesson 22 – Understanding Multidimensional Arrays
  • Lesson 23 – Changing the Length of an Array
  • Challenge 6 ChallengeEpicSpiesAssetTracker
    • Solution 6 ChallengeEpicSpiesAssetTracker
  • Lesson 24 – Understanding Variable Scope
  • Lesson 25 – Code Blocks and Nested Statements
  • Lesson 26 – Looping with the for Iteration Statement
  • Challenge 7 ChallengeForXmenBattleCount
    • Solution 7 ChallengeForXmenBattleCount
  • Lesson 27 – Looping with the while() & do…while() Iteration Statements
• METHODS
  • Lesson 28 – Creating and Calling Simple Helper Methods
  • Lesson 29 – Creating Methods with Input Parameters
  • Lesson 30 – Returning Values from Methods
  • Lesson 31 – Creating Overloaded Methods
  • Lesson 32 – Creating Optional Parameters
  • Lesson 33 – Creating Named Parameters
  • Lesson 34 – Creating Methods with Output Parameters
  • Challenge 8 ChallengePostalCalculatorHelperMethods
    • Solution 8 ChallengePostalCalculatorHelperMethods
  • Challenge MegaChallengeCasino
    • Solution MegaChallengeCasino
• WORKING WITH STRINGS
  • Lesson 35 – Manipulating Strings
  • Challenge 9 ChallengePhunWithStrings
    • Solution 9 ChallengePhunWithStrings
• CLASSES AND OBJECTS
  • Lesson 36 – Introduction to Classes and Objects
  • Challenge Hero Monster Classes Part 1
    • Solution - Challenge Hero Monster Classes Part 1
  • Challenge Hero Monster Classes Part 2
    • Solution - Challenge Hero Monster Classes Part 2
  • Lesson 37 – Creating Class Files, Creating Cohesive Classes and Code Navigation
  • Lesson 38 – Understanding Object References and Object Lifetime
  • Lesson 39 – Understanding the .NET Framework and Compilation
• ASSEMBLIES, NAMESPACES, CLASS MEMBERS
  • Lesson 40 – Namespaces and Using Directives
  • Lesson 41 – Creating Class Libraries and Adding References to Assemblies
  • Lesson 42 – Accessibility Modifiers, Fields and Properties
  • Lesson 43 – Creating Constructor Methods
  • Lesson 44 – Naming Conventions for Identifiers
  • Lesson 45 – Static vs. Instance Members
  • Challenge 10 ChallengeSimpleDarts
    • Solution 10 ChallengeSimpleDarts
• WORKING WITH COLLECTIONS
  • Lesson 46 – Working with the List Collection
  • Lesson 47 – Object Intializers
  • Lesson 48 – Collection Initializers
  • Lesson 49 – Working with the Dictionary Collection
  • Lesson 50 – Looping with the foreach Iteration Statement
  • Lesson 51 – Implicitly Typed Variables with the Var Keyword
  • Challenge 11 ChallengeStudentCourses
    • Solution 11 ChallengeStudentCourses
  • Challenge MegaChallengeWar
    • Solution MegaChallengeWar
• APPLICATION STRUCTURE
  • Lesson 52 – Creating GUIDs
  • Lesson 53 – Working with Enumerations
  • Lesson 54 – Understanding the switch() Statement
  • Lesson 55 – First Pass at the Separation of Concerns Principle
  • Lesson 56 – Understanding Exception Handling
  • Lesson 57 – Understanding Global Exception Handling
  • Lesson 58 – Understanding Custom Exceptions
  • Lesson 59 – Creating a Database in Visual Studio
  • Lesson 60 – Creating an Entity Data Model
  • Lesson 61 – Displaying the DBSet Result in an ASP.NET GridView
  • Lesson 62 – Implementing a Button Command in a GridView
  • Lesson 63 – Using a Tools-Centric Approach to Building a Database Application
  • Lesson 64 – Using a Maintenance Driven Approach to Building a Database Application
  • Lesson 65 – Creating a new Instance of an Entity and Persisting to the Database
  • Lesson 66 – Package Management with NuGet
  • Lesson 67 – NuGet No Commit Workflow
  • Lesson 68 – Introduction to the Twitter Bootstrap CSS Framework
  • Lesson 69 – Mapping Enum Types to Entity Properties in the Framework Designer
  • Lesson 70 – Deploying the App to Microsoft Azure Web Services Web Apps
  • Papa Bob's Mega Challenge
    • Papa Bob's Mega Solution Part 1 - Setting up the Solution
    • Papa Bob's Mega Solution Part 2 - Adding an Order to the Database
    • Papa Bob's Mega Solution Part 3 - Passing an Order from the Presentation Layer
    • Papa Bob's Mega Solution Part 4 - Creating the Order Form
    • Papa Bob's Mega Solution Part 5 - Adding Enums
    • Papa Bob's Mega Solution Part 6 - Creating an Order with Validation
    • Papa Bob's Mega Solution Part 7 - Calculating the Order Price
    • Papa Bob's Mega Solution Part 8 - Displaying the Price to the User
    • Papa Bob's Mega Solution Part 9 - Creating the Order Management Page