[Solved] CECS475 Assignment 3- Delegates and Events

Read the following lecture note

Delegates and Events pdf word Code example word and implement the following:

1. Delegate event without passing data
2. Delegate event with passing data
3. Rewrite item a using .NET EventHandler
4. Rewrite item b using .NET EventHandler

Grading

• Demonstrate the result to the instructor in the class
• Return a printed copy of the answers to the following questions:
  1. Briefly describe how you convert part a to c by showing the code that is modified for using .NET event handler.
  2. Briefly describe how you convert part a to c by showing the code that is modified for using .NET event handler.

Problem 2

In this lab assignment , you create an application that models the ups and downs of a particular stock. The value of a stock is assumed to change by plus or minus a

specified number of units after every time unit (such as one hour). A notification is generated each time a stock changes more than a specified number of units above or below its intial value. A collection of brokers who control the stock must receive this notification. The range within which the stock can change every time unit and the threshold above or below which collection of brokers who control the stock must be notified are specified when the stock is created (using its constructor).

You shall design and implement a C# application that satisfies the specification given above. This application involves delegates, events and threads. You begin by defining a delegate class StockNotification. This is shown below.

public delegate void StockNotification(String stockName, int currentValue, int numberChanges);

This delegate is designed so that when an event of this type is fired, the stocks name, value, and the number of changes in value can be sent to the listener.

Create the class Stock with the following attributes:

• Stock name
• Stock intial value
• Maximum change (the range within a stock can change every time unit)
• Notification threshold (the threshold above or below which the collection of brokers who control the stock must be notified)

You are required to implement other members in the class Stock that are needed. When a stock object is created, a thread is started. This thread causes the stocks value to be modified every 500 milliseconds. If its value changes from its initial value by more than the specified notification threshold, an event method is invoked. This invokes the stockEvent (of event-type StockNotification) and multicasts a notification to all listeners who have registered with stockEvent.

Create another event to notify saving the following information to a file when the stocks threshold is reached: date and time, stock name, inital value and current value.

Create the class StockBroker which has fields broker name and stocks, a List of Stock. This latter field is not used in this application but could be used to obtain the stocks currently controlled by a given broker. The addStock method registers the Notify listerner with the stock (in addition to adding it to the list of stocks held by the broker). This Notify method outputs to the console the name, value, and the number of changes of the stock whose value is out of the range given the stocks notification threshold.

The listing below presents a main driver class, StockApplication.

static void Main(string[] args)

{

Stock stock1 = new Stock(Technology,160, 5, 15);

Stock stock2 = new Stock(Retail,30, 2, 6);

Stock stock3 = new Stock(Banking, 90, 4, 10);

Stock stock4 = new Stock(Commodity, 500, 20, 50);

StockBroker b1 = new StockBroker(Broker 1); b1.AddStock(stock1); b1.AddStock(stock2);

StockBroker b2 = new StockBroker(Broker 2); b2.AddStock(stock1); b2.AddStock(stock3); b2.AddStock(stock4);

StockBroker b3 = new StockBroker(Broker 3); b3.AddStock(stock1); b3.AddStock(stock3);

StockBroker b4 = new StockBroker(Broker 4); b4.AddStock(stock1); b4.AddStock(stock2); b4.AddStock(stock3); b4.AddStock(stock4); }

The output sample:

Broker Stock Value Changes

Broker 2 Commodity 553 4

Broker 4 Commodity 553 4

Broker 1 Technology 177 5

Broker 2 Technology 177 5

Broker 3 Technology 177 5

Broker 4 Technology 177 5

Broker 2 Banking 103 5

Broker 2 Commodity 571 5

Broker 4 Commodity 571 5

Broker 3 Banking 103 5

Broker 4 Banking 103 5

Broker 1 Technology 179 6

Broker 2 Technology 179 6

Broker 3 Technology 179 6

Broker 4 Technology 179 6

Broker 2 Banking 105 6

Broker 3 Banking 105 6

Broker 4 Banking 105 6

Broker 2 Commodity 581 6

Broker 4 Commodity 581 6 Broker 1 Technology 181 7

Broker 2 Technology 181 7

Broker 1 Retail 37 7

Broker 4 Retail 37 7

Broker 2 Banking 107 7

Broker 3 Banking 107 7

Broker 4 Banking 107 7

Broker 2 Commodity 588 7

Broker 4 Commodity 588 7

Broker 3 Technology 181 7

Broker 4 Technology 181 7

Broker 2 Banking 108 8

Broker 1 Retail 38 8

Broker 2 Commodity 589 8

Broker 1 Technology 182 8

Resources for lab 3

1. Lecture note on lab 3 (pdf)
2. Multithreading in C#
3. Thread synchronization
4. Write to a text file in C#