Hi all, can someone please clear things up for me regarding inheriting an abstract class. According to msdn.com[^] the following are some of the features of an abstract class:
It is not possible to modify an abstract class with the sealed modifier, which means that the class cannot be inherited.
A non-abstract class derived from an abstract class must include actual implementations of all inherited abstract methods and accessors.
The first sentence says that the class cannot be inherited but the second sentence says you can have a non-abstract class which is derived from an abstract class. If I'm not mistaken, a derived class is a class that inherits from another class. Thanks in advance for your response.
MSDN isn't always right and sometimes, like here, they don't update the documentation. If you follow the 'other versions' links, at the top of that page, to VS 2012, you'll see that the stuff about 'abstract sealed' has been changed.
It's possible that the person who wrote the docs was confusing C# and intermediate language (IL) classes. When a C# static class is compiled to IL, the class declaration is marked as abstract and sealed. So a C# static class is equivalent to an IL abstract sealed class.
In C# it's not actually possible to declare a class as 'abstract sealed'. Try it and you'll find that it won't compile.
I agree that this sentence could be clearer. What they're trying to say is:
You cannot add the sealed modifier to an abstract class;
The sealed modifier means that a class cannot be inherited;
It looks like they cleared this up in the VS2010 version[^], where the sentence has been changed to:
It is not possible to modify an abstract class with the sealed (C# Reference) modifier because the two modifers have opposite meanings. The sealed modifier prevents a class from being inherited and the abstract modifier requires a class to be inherited.
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In a C# 2008 application, I used linq to sql to connect to a sql server 2008 database. Now I want to obtain the connection of the database from the
app.config file instead of hardcoding the value into the application. I want to be able to change the connection string to the database since I will be moving this application from unit testing database to user acceptance database to the the prodction database.
Right now I am getting the error message, ""Object reference not set to an instance of an object." I know this error message is coming from the line of code that I listed below since it is the only line of code I changed.
The following is a snippet of the code from the *.designer.cs file (this is part of the dbml file).
public esampleDataContext() :
**Note: base(global::sample.Properties.Settings.Default.DEVConnectionString, mappingSource) is the line of code that I replaced that was generated by the
I want to mention the following:
1. The *.dbml file is associated with a particular project file.
2. The connection string settings for this *.dbml file are the following:
a. DEVConnectionString (settings)
b. Connection String = Data Source=dev1;Initial Catalog=DEV_test;Integrated Security=True
c. application settings=True
d. settings property name is DEVConnectionString.
3. The project file that has the *.dbml file. has a reference set to the system.configuration.
**Note: This code in similar applications that I wrote, but I do not why it does not work here.
Thus can you tell me, show me in code, and/or point me to a reference that I can use so I can obtain the value in the app.config file for the database connection string I want to use. I do not want to use a hard-coded connection string to the database.
point me to a reference that I can use so I can obtain the value in the app.config file for the database connection string I want to use. I do not want to use a hard-coded connection string to the database.
Correct me if I'm wrong, but isn't the connectionstring in the app.config file? Isn't the app.config file an XML file that can be edited?
If both answers are yes, then your connectionstring isn't hardcoded, but loaded from the settings-file.
The problem is the settings-file does not get the value from the app.config file. The values are retained in the settings-file from the time I orginally created the app.config file. The settings-file needs to change at some point.
Your app.config needs to be set up in a very specific way for that to work.
If it isn't set up that way then ConnectionStrings will be null.
I would suggest that you do the following
1. Create a project/app that ONLY gets the connection string
2. Create a app.config that ONLY has that connection string.
3. Verify in that app that ConnectionStrings is not null before using it.
4. Get the connection string property and print it.
Then if that doesn't work then you can post the entire class and the entire app.config. Do not include real info in the app.config all you care about is that it get a value not what is in it.
i am developing a win apps where many .rdlc are there in report folder of that project. when i will create a setup for delivery to client then do i need to include all those .rdlc file manually or it will be included automatically like .rpt (crystal report) files.
what i can do as a result always .rdlc files will be automatically included when i will batch build of my project. anyone can guide me. thanks
i understand that you are talking about RDL report which is stored in sql server database but here i asked about RDLC which is client side.i asked how could i distribute my rdlc files with my application setup as a result when client install my setup then he can view the report which is based on rdlc. i like to know what is industry standard way to include rdlc into setup project. if you such thing then please advise. thanks
No I was talking about a strategy for distributing RDLC reports. You can include the reports in a folder in your setup project. I don't believe there is an 'industry standard' as most installer tool work differently.
I find that the reporting requirement changes as the user gets familiar with the application and additional reports are always needed AFTER delivering the application.
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i know it is possible that we can create a folder and include report manually every time before building setup but i want to know is there any automated process by which report will be added automatically every time when we build setup from a particular folder. let me know.thanks
I'm not up with winforms deployment as I'm using Silverlight but I would have thought that once you have completed a reports development and testing that you move it to a deployment folder and include that folder in the deployment build!
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I am using Visual 2010 and sap crystal report 2010. When displayed on the report is correct, but when exported to excel from report tool does not display properly.Have you asked yourself how to fix it. Thanks!
I created a new WinForms project and got this error:
The designer could not be shown for this file because none of the classes within it can be designed.
I have not yet added any code to the project. It appears as if all of the necessary assemblies are referenced, but intellisense can't seem to resolve the Form class.
Shutting VS2012 down and starting it back up again solved the issue. Weird.
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Maybe the fact that I mentioned WPF when the OP was looking for ASP.NET was the reason. I don't see how my answer was wrong in that context as you could esily substitute the WPF front end with a ASP.NET version (or have both, and....).
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