1. If you do not specify the action, the form goes right back to itself. This is called a postback form because it post back to itself.
2.Upon the first time code is submitted to the server it is compiled and ASP does not compile tags it does not recognize. Once the code is compiled, ASP.Net start processing all the user code and event handlers. Event handlers have the following parameters: sender as object and E as eventargs.
3. ASP.Net automatically keeps track of the view state. Developers do not have to maintain or retrieve data being input on the form between different view states.
4. VB.NET variable types are: Byte, short, integer, long, single, double, decimal, char, date, boolean, string, datetime, and objects
5. VB.NET conversion functions are: Cbool, CDec, Cobj, CType, CByte, Cdbl, CShort, Asc, CChar, CInt, CSng, CDate, CLng, Cstr
6. You can create and define code in your event handler "sub handlers button_click(sender as object, e as event args)". When an event is raised - meaning the event happened - it produces variables that describe the event. The object data type represent the object that raised the event.
7. Date/Time functions: datediff, firstdayofweek, day, dayofweek, hour, isdate, minute, now, month,, second, year.
8. Math functions: abs, atan, cos, exp,fix, hex, int, log, oct. rnd, round, sin, sqrt, tan
9. String functions: instr, left, len, mid, replace, right.
10. Buffering allows you to control when output is sent to the browser. Response.buffer = false turns off buffering. When output is buffered, nothing is sent to the buffer until all the code has been executed or the buffer is full. Unbuffered output goes immediately to the browser. Response.flush forces the buffer to empty to the browser.
11. If you create a cookie with a value and then add keys, the initial value will be erased. You can not create cookies with both values and keys.
12. If the browser does not support session cookies, ASP.Net tacks on an encoded version of the session id to a link. When a user clicks a link, ASP decodes the session id and passes to the page the user is requesting.
13. Web forms handles all events and generates html on the server. "
14. The Web forms processing order: a. page is requested b. viewstate is restored for any controls c. the page_load event occurs d. events are handled, the page_unload event occurs.
15. The autopostback=true attribute cause the eventhandler to be executed immediately on event. Defined as "OnTextchanged='myhandler'", when the text has changed, a post will occur, and the myhandler function will be called.
16. The web forms framework is a huge boon for Web developers, both in UI creation and application logic. Once you've been developing with Web forms for a while, you'll wonder how you ever lived without them!
17. Accessing Data with ASP.Net: a. setup a database connection b. open the database connection c. fill a dataset with the desired date d. setup a dataview to display the data e. bind a server control to the dataview through the databinding method of the control.
18. ADO.NET full embraces XML, allowing it to communicate with XML compliant applications. ADO.Net revolves around the dataset. A dataset is a memory resident data store that provides a consistent program model for accessing data. A data set contains sets of data, constraints, relationships, and even multiple tables.
19. There are two ways to use a data store: a. Fill it with another data store c) create your own data store. The Data store has a table collections called ds.tables("name"). The ds.tables("name").primary=datacolumn defines the primary key where the datacolumn has two parameters a name and data type. Other columns can be defined for columns collection in by using ds.tables("name").columns.add(datacollection). Data Relationships form follows as, dataRelations("name",datacolumn1,datacolumn2) and joins the relations collection ds.tables("name").relations.add(datarelations). Last Datarows can be inserted using dr=new datarow where dr(index)=value and the index is the field index assigned a value. The datarow joins the ds.tables("name").rows.add(datarow), the datarows collection.
20. ADO.Net Dataset has a number of advantages: Scalability - no locks or active connections; Firewalls - XML is completely firewall proof; Programmability - does not require use of data contructs; sharing data - no data conversions are required; relationships - object structure maintains the relationship; data access - non sequential access to the multiple table data.
21. Many companies try to build propriety communication systems that allow services to be exchanged, but these are often to expensive and complicated to maintain. A web service is a programmable object that provides functionality that's accessible to any number of systems over the internet. Web services rely on the fact that any type of system or application can use http.
22. Why use web services. Corporations are trying to tie traditional applications together into a single composite entity. Web services provide a very simple mechanism for applications to communicate with each other. With Webservices you can reuse code that other people have developed. Web service files are vb.net or c# files that end in an .asmx extension.
23. A Webservice uses an XML format call the Service Description Language (SDL) to tell the clients what can be done with the service. Webservices have methods just as regular classes and business objects do.
24. Discover is the process by which a client finds out about a Web Service. Calling the service from code is simple.
Dim objCalculator As New CalculatorService