-
Home
- Ti dsp/bios lab
- Lab 5
- Microsoft visual basic delegate
The module is a lab assignment to help you better understand the very basics of Microsoft Visual Basic delegates.
Introduction
This lab module will help you become familiar with the basics of delegates in Microsoft Visual Basic(V). The exercises are written assuming you are using Visual Basic 2005 and the .NET Framework version 2.0 (or later). Some older versions will work the same, but you may need to figure out some differences. It should work with newer version also.
Module prerequisites
You should complete the Visual Basic Threads and Semaphores lab before this one.
Labratory
Part 1
- In this part you will make a project with a thread that will try to change a TextBox text without using a delegate method. When the thread tries to change the TextBox text it won't work because the TextBox control is not handled by the thread.
- Start up Visual Studio and create a new Visual Basic project.
- On the GUI, put a new TextBox. By default it should have the name
TextBox1 .
- Create a thread called
Task1 and start the thread in the
Form1_Load method.
- In the thread method
Task1 , assign a string to the TextBox.
- Run your program and observe what happens. You should get an error when the thread tries to access the TextBox control. Record what the error says.
Part 2
- In this part we will make a delegate that will allow the thread to change the text in the TextBox.
- Either start a new project or modify the one from the previous part. What you should have in your project is:
- A TextBox on the GUI with the name
TextBox1 .
- A thread called
Task1 that is started in the
Form1_Load method.
- Add commands to define a delegate type and an instance of a delegate. If you want to use the names shown here you can. These statements should be right under the beginning of the Form1 class (right after "
Public Class Form1 ").
Delegate Sub DelegateType(ByVal myStr As String)
Dim IDel As New DelegateType(AddressOf DelegateMethod)
- Make a new
DelegateMethod method that takes a string as an input and uses it to change the text of the TextBox.
- In the
Task1 method, use the
TextBox1 to invoke the delegate method. Have it write the text
"Task Text" to the TextBox.
- Run your program and observe that the text
"Task Text" gets written to the TextBox.
Part 3
- In this part we will make a simple clock. All we will do is continuously get the current time and write it to the TextBox.
- In this part we will have everything that is in the previous part so you can start where it left off. Your project should have:
- A TextBox on the GUI with the name
TextBox1 .
- A thread that uses the
Task1 method that is started in the
Form1_Load method.
- Commands to define a delegate and an instance of a delegate.
- A delegate method that writes the input string to the TextBox.
- In the thread, we will have it get the current date/time and the write it to the TextBox.
- Put the following commands that will define objects to get the current date/time.
Dim count As Integer
Dim dispDt As DateTimeDim datePatt As String = "M/d/yyyy hh:mm:ss tt"
Dim dtString As String
- In the thread make a continuous while loop that puts the date into the string
dtString and then sends that string to the delegate. To get the date use the command:
dispDt = DateTime.Now ' get the time now
dtString = dispDt.ToString(datePatt) ' Convert the date to a string
- In the while loop make the thread sleep for 100 ms so that it is not doing too much processing. It will get the time/date and write it to the TextBox every 100 ms.
- Run your program and observe that the text displays the date/time and that the seconds change.
Questions & Answers
differentiate between demand and supply
giving examples
differentiated between demand and supply using examples
Lambiv
how is the graph works?I don't fully understand
hi guys good evening to all
Lambiv
In economics, a perfect market refers to a theoretical construct where all participants have perfect information, goods are homogenous, there are no barriers to entry or exit, and prices are determined solely by supply and demand. It's an idealized model used for analysis,
Ezea
other things being equal
AI-Robot
When MP₁ becomes negative, TP start to decline.
Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 •
Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of lab
Kelo
Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 •
Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of labour (APL) and marginal product of labour (MPL)
Kelo
Can I ask you other question?
Shukri
What is different between quantity demand and demand?
Quantity demanded refers to the specific amount of a good or service that consumers are willing and able to purchase at a give price and within a specific time period. Demand, on the other hand, is a broader concept that encompasses the entire relationship between price and quantity demanded
Ezea
how do you save a country economic situation when it's falling apart
what is the difference between economic growth and development
Economic growth as an increase in the production and consumption of goods and services within an economy.but
Economic development as a broader concept that encompasses not only economic growth but also social & human well being.
Shukri
production function means
Jabir
What do you think is more important to focus on when considering inequality ?
any question about economics?
sir...I just want to ask one question... Define the term contract curve? if you are free please help me to find this answer 🙏
Asui
it is a curve that we get after connecting the pareto optimal combinations of two consumers after their mutually beneficial trade offs
Awais
thank you so much 👍 sir
Asui
In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities, where neither p
Cornelius
In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities,
Cornelius
Suppose a consumer consuming two commodities X and Y has
The following utility function u=X0.4 Y0.6. If the price of the X and Y are 2 and 3 respectively and income Constraint is birr 50.
A,Calculate quantities of x and y which maximize utility.
B,Calculate value of Lagrange multiplier.
C,Calculate quantities of X and Y consumed with a given price.
D,alculate optimum level of output .
the market for lemon has 10 potential consumers, each having an individual demand curve p=101-10Qi, where p is price in dollar's per cup and Qi is the number of cups demanded per week by the i th consumer.Find the market demand curve using algebra. Draw an individual demand curve and the market dema
suppose the production function is given by ( L, K)=L¼K¾.assuming capital is fixed find APL and MPL. consider the following short run production function:Q=6L²-0.4L³ a) find the value of L that maximizes output b)find the value of L that maximizes marginal product
Abdureman
What is the difference between perfect competition and monopolistic competition?
Mohammed
Got questions? Join the online conversation and get instant answers!
Source:
OpenStax, Ti dsp/bios lab. OpenStax CNX. Sep 03, 2013 Download for free at http://cnx.org/content/col11265/1.8
Google Play and the Google Play logo are trademarks of Google Inc.
