Architecture :: What Is The Function Of Abstract Class
Oct 24, 2010what is the function of abstract class, why design pattern need to build BLL and DAL
anyone give an example for my reference as I am getting strat to build my web-based project
Similar Messages:
Architecture :: Singleton Pattern And Abstract Class?
Aug 19, 2010I know what Singleton Pattern means and Abstract class means.What I wanted to know was how would this apply to real world.Could anyone give me any good example or simple explanation.Say I have a simple website, why would I use any of the above if any.Why would it simplify my architechture.
View 3 RepliesArchitecture :: Use Of Abstract Class Design In Real Time Projects?
Jul 21, 2010What is the use of abstract class design in real time projects
and how to use abstract clases and interfaces
and inheritense concepts
like big shoping portals or content managment,blogs etc
Architecture :: Interface, Abstract Or Inheritance?
Oct 7, 2010I have a table which houses two entities. StaticProgram and DynamicProgram. There is one column in that table called ProgramType which determines if a program is of Type static or Dynamic. Though these two entities are stored in one table (I am guessing because the primitive fields for Static and Dynamic programs are exactly the same) but from a business point of view these are two VERY different entities.
So, I created two Classes StaticProgram and DynamicProgram. However, I donot want to create two seperate Data Access Classes because it is going to be the exact same code replicated twice. I tried creating a "Program" class as base class and inherited StaticProgram and DynamicProgram classes but down casting is not supported so I can't return a "Program" object from the data access class and cast it to "StaticProgram" class.So, what are my options? Can I create an IProgram interface and have StaticProgram and DynamicProgram implement that interface and have my Data Access class return IProgram?
Use Abstract Class And Interface Class?
Jan 29, 2010When to use Abstract class and when to use Interface class.
View 10 RepliesRecommendations For Abstract Class Vs Interfaces?
Dec 21, 2010From the following URL i got some doubts about the Recommendations for using Abstract class vs interfaces
[URL]
1. If you anticipate creating multiple versions of your component, create an abstract class. Abstract classes provide a simple and easy way to version your components. By updating the base class, all inheriting classes are automatically updated with the change. Interfaces, on the other hand, cannot be changed once created. If a new version of an interface is required, you must create a whole new interface. { Is there any example for this t ounderstand throughly ?} If you are designing small, concise bits of functionality, use interfaces. If you are designing large functional units, use an abstract class. If you want to provide common, implemented functionality among all implementations of your component, use an abstract class. Abstract classes allow you to partially implement your class, whereas interfaces contain no implementation for any members. { Is there any example for this t ounderstand throughly?
C# - Cannot Create Instance Of Abstract Class?
Mar 31, 2010I am trying to compile the following code and i am getting the error:
Cannot create instance of abstract class .
m_objExcel = new Excel.Application();
m_objBooks = (Excel.Workbooks)m_objExcel.Workbooks;
m_objBook = (Excel._Workbook)(m_objBooks.Add(m_objOpt));
m_objSheets = (Excel.Sheets)m_objBook.Worksheets;
m_objSheet = (Excel._Worksheet)(m_objSheets.get_Item(1));
// Create an array for the headers and add it to cells A1:C1.
object[] objHeaders = {"Order ID", "Amount", "Tax"};
m_objRange = m_objSheet.get_Range("A1", "C1");
m_objRange.Value = objHeaders;
m_objFont = m_objRange.Font;
m_objFont.Bold=true;
// Create an array with 3 columns and 100 rows and add it to
// the worksheet starting at cell A2.
object[,] objData = new Object[100,3];
Random rdm = new Random((int)DateTime.Now.Ticks);
double nOrderAmt, nTax;
for(int r=0;r<100;r++)
{
objData[r,0] = "ORD" + r.ToString("0000");
nOrderAmt = rdm.Next(1000);
objData[r,1] = nOrderAmt.ToString("c");
nTax = nOrderAmt*0.07;
objData[r,2] = nTax.ToString("c");
}
m_objRange = m_objSheet.get_Range("A2", m_objOpt);
m_objRange = m_objRange.get_Resize(100,3);
m_objRange.Value = objData;
// Save the Workbook and quit Excel.
m_objBook.SaveAs(m_strSampleFolder + "Book2.xls", m_objOpt, m_objOpt,
m_objOpt, m_objOpt, m_objOpt, Excel.XlSaveAsAccessMode.xlNoChange,
m_objOpt, m_objOpt, m_objOpt, m_objOpt);
m_objBook.Close(false, m_objOpt, m_objOpt);
m_objExcel.Quit();
Use Of Abstract Class In Shopping Portal?
Jul 27, 2010I just want to know that how can I utilize the concept of Abstract class, virtual class etc. in my shopping cart website. I have read the tutorial out there on internet and I saw some examples too, but those examples are so general that they dosen't fit into real world scenerio like I am searching for a shopping website. Same questions again and again comes to my mind that why to made a class only to give the declaration of methods and property.
View 4 RepliesCannot Create The Object Of Abstract Class
Apr 22, 2010We all know that, we cannot create the object of Abstract class.
But why it is so?
I mean, can anyone explain it with real time example?
Why Use Reference Of Abstract Class To Create Object
Jul 22, 2010Why do we use the reference of abstract class (or base class) to create object of it's sub-class. eg: TextWriter is the abstract class for StreamWriter & StreamWriter.
TextWriter writer = new StreamWriter();
why can't we simply use :
StreamWriter writer = new StreamWriter();
MVC :: Cannot Create An Instance Of The Abstract Class Or Interface?
Dec 12, 2010Error 1279 Cannot create an instance of the abstract class or interface 'System.Web.Mvc.FileResult'
[Code]....
I am using MVC 2. The same code works in my onather application. I have no idea about this error.
Creating An Abstract Class That Will Define All Database Manipulation Methods To Implement
Mar 3, 2010I am developing a couple of small ASP.NET application and would like to know what pattern. approach do you use in your projects.
My projects involve databases, using Data access and Business logic layers.
The data-access approach that I was using so far is the following(I read in some book and liked it):
For DAL layer:
Creating an abstract class that will define all database manipulation methods to implement.
The abstract class will contain a static "Instance" property, that will load (if instance == null) an instance (Activator.CreateInstance) of the needed type (a class that implements it).
Creating a classes that implement this abstract class, the implementation will be according to the databases (SQL, mySQL and etc) in use.
With this I can create different implementation according to database in use.
For BLL layer:
A class that encapsulates all all retrieved fields , and static methods that will call the DAL classes.
Forms Data Controls :: Binding Repeater To List (of Abstract Class)?
Feb 18, 2010I am attempting to bind a Repeater (but it could be a GridView or ListView) to a list of objects. The List's type is an abstract type, which has two different classes derived from it, both with different properties. Because they have different properties, I cannot just have one ItemTemplate. If I bind a control to a property of one type of class and the other type doesn't have it, it throws an error.
Here's where I'm at:
I cannot use <% if (whatever) { %> some stuff <% } else { %> some other stuff <% } %> because I cannot access the databound item to make the choice based on its type. I cannot use the <%# %> syntax, which lets me use the databound information, because you cannot code logic like if...then...else. I cannot (rather not) call a function and return a string with the code because what I want to render is complex and contains further nested databound controls. Has anyone found an ingenious way of doing if it is this type of object, display these controls, else display these other controls?
C# - Class Structure With LINQ, Partial Classes, And Abstract Classes
May 17, 2010I am following the Nerd Dinner tutorial as I'm learning ASP.NET MVC, and I am currently on Step 3: Building the Model. One part of this section discusses how to integrate validation and business rule logic with the model classes. All this makes perfect sense. However, in the case of this source code, the author only validates one class: Dinner.
What I am wondering is, say I have multiple classes that need validation (Dinner, Guest, etc). It doesn't seem smart to me to repeatedly write these two methods in the partial class:
[code]....
This doesn't "feel" right, but I wanted to check with SO to get opinions of individuals smarter than me on this. I also tested it out, and it seems that the partial keyword on the OnValidate method is causing problems (understandably so). This doesn't seem possible to fix (but I could very well be wrong).
Architecture :: Function Implementation In 3-tier Architecture?
Apr 28, 2010I have implemented the 3-tier architecture project; DAL, BAL, and presentation layer are three layers in it. I am going to implement the following scenario:
Presentation layer calls to a function in the BAL layer which returns 2 string variable, and in turn this function from BAL layer calls to a DAL layer function which also returns 2 string variable. How can I implement the above scenario?
BareMessage="Cannot Create An Abstract Class."?
Jun 18, 2010Configuration Error Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately. Parser Error Message: Cannot create an abstract class.
Source Error:
Line 150: <providers>
Line 151: <clear/>
Line 152: <add name="NDMSMembershipProvider"
type="CSW.Web.Security.NDMSMemberProvider"/>
Line 153: </providers>
Line 154: </membership>
Source File: C:DevCSW2srcCSW.Webweb.config Line: 152
Architecture :: Use A C# Class Or A Interface?
Feb 3, 2011I have a block of SQL statements that I like to use as a sort of function.
I was thinking that I could make a class and inherit all of the master function, then add the parts that I need for other sections of the program in a sub class.
The problem is, up to this point I've been programming ASP .Net through visual studio, and it's kind of just programming behind controls. I'm not sure where to put the class/function/method/interface, or whatever we call it.
Of course you probably know that visual studio creates a bunch of partial classes when you do an ASP. Net application... so.. to get access to a function like object, across classes.. use an Interface?
Architecture :: Add Event/function To All Pages In Existing App?
Jan 26, 2011c#/vb webapp. I'm working on a very old app with a ton of pages. I want to add a function to every page's PreRender. If this application was designed properly from the start, it would use a MasterPage, or would at least inherit all pages from a BasePage other than System.Web.UI.Page.The goal is that every aspx page's PreRender should trigger a call to FooFunction(). I'd like to have this done all in one page, to avoid opening every single .aspx file and changing it's inheritence / pasting FooFunction() / some other time waster.Is there a way to do this in .net? Can you point me in the direction of any design/discussion articles?
View 5 RepliesArchitecture :: How To Make The Class Libraries
Jan 22, 2010Task is to develop class libraries that can be re-use in projects but assambies should be copy righted. By this I mean developer will not give the code of class libraries to the clients yet they will provide the code of there sites/ applications, these libraries will be used just as internal development libraries. I want to make Business Logic Layer, DAL, Business Objects as class libraries
Q1. How I can control unathorised use of libraries ?
Q2. How to make assamlies non extendable ?
Q3. What security measurs I should take on this.
Architecture :: Key, Value Pairs Implementation In Class?
Feb 16, 2010In a project im working on there are many sql tables containing different ID, Name pairs. Those are represented as Enums in classes that need them however that requires casting since tables contain ID only.Also when serialize the Enum contains the ID not value.
View 3 RepliesArchitecture :: Extract Large Data From SQL To CSV Using Asynchronous Function
Oct 16, 2010I have a table growth 100000row per day, I'm facing many problems to export data from this table using ASP.net page.
I don't know how to apply this scenario:
Senerio 1:
1- run Asynchronous function to export data from SQL for specified period to CSV file (without locking the table)
2- Refresh page every 5 sec in order to track the status of extracting data
3- compress the file
4- Stop refreshing and showing the download link in order to download the compressed file
or
Senerio 2:
1- run Asynchronous function to export data from SQL for specified period to CSV file (without locking the table)
3- compress the file
4- send the compressed file by Email
Architecture :: Creating A DB Connection In My DAL Class File?
Feb 17, 2010Below is my class file.
[Code]....
Architecture :: Advantage Of Singleton Class Over Static?
Mar 30, 2010See in below I have writtine a
1. Singleton class Emp1 with Display Method and
2. Static Class with Static Method Display.
What is the advantage of singleton class over Static Class with Static members?
[Code]....
Architecture :: Singleton Class Could Be Inherited And Derived?
Oct 25, 2010Just wanted to know if a singleton class could be inherited and derived.
View 2 RepliesArchitecture :: Design A Class For Product Searching?
Oct 21, 2010I'm refactoring an old website that has product search code littered throught the codebehind. I'm trying to encapsulate the search logic into its own class so I've created a Product class with a Search() method. I would like some suggestions about OO best practices so that the class is reusable and maintainable. The questions I have are:
- Should I make the search() method an instance method or make it static? For now the class is just really there to encapsulate my search logic
- If I make it an instance method should it return a list of products or should it populate a member property that I can access like p.Search(); var x = p.ProductList;
- The search method requires upward of 7 parameters of different types, what's the best way to provide them?
- pass them all i.e. p.Search (param1, param2, ..., param7)
- create a SearchParams structure in the class, populate it and pass that i.e. p.Search(searchParams)
- Instantiate a Product object and set properties on it that are used by the Search method i.e. p.ID = 123; etc.... p.Search();
I've used variations of the above before but would like to know what's the best way.