CECS 475 Lab Assignment 3 Solved

CECS 475 
Lab Assignment 3 

50 points

Problem 1 [10 points] 

Read the following lecture note

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

a.     Delegate event without passing data

b.    Delegate event with passing data

c.     Rewrite item a using .NET EventHandler

d.    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 [40 points] - Due Wednesday 9/18

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 stock's 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 stock's 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 stock's 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 stock's 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#