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Hi, I am trying to access a MS Access database using Windows form. I added my connection string in App.congig file.
="1.0"="utf-8"
<configuration>
<connectionStrings>
<clear/>
<add name="Constr" providerName="System.Data.OleDb"
connectionString="Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\\Users\\XXXX\\Documents\\YYYYY.accdb; Persist Security Info=False;"/>
</connectionStrings>
</configuration>
Code I added in my code to read this is
string connectionstring = ConfigurationManager.ConnectionStrings["Constr"].ConnectionString;
but I am getting following error on this line.
System.NullReferenceException was unhandled
Message=Object reference not set to an instance of an object.
Source=LoadTrackingTool.
I am not getting why I am getting this error. Can anyone please help me out in this. I am new in this functionality.
Thnx,
Aduu
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Stack Traces do help!
put it there please!
A train station is where the train stops. A bus station is where the bus stops. On my desk, I have a work station....
_________________________________________________________
My programs never have bugs, they just develop random features.
modified 12-Nov-12 1:17am.
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You'll have to step through the code and find what line of code causes the error. At a quick glance I don't think it is failing on getting the connection string.
There are only 10 types of people in the world, those who understand binary and those who don't.
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have you tried
string connectionString = ConfigurationManager.ConnectionStrings["Constr"].ToString();
Simon
Lobster Thermidor aux crevettes with a Mornay sauce, served in a Provençale manner with shallots and aubergines, garnished with truffle pate, brandy and a fried egg on top and Spam - Monty Python Spam Sketch
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hi
i build my Webservice on FrameWork 3.5 (C# Visual studio 2008)
it work excellent on Windows-7 and XP - and it work excellent if i run Through Visual-Studio.
i try to run on Windows-8 and i got error.
1. i try to setup the Application pool IIS on .NET v2.0 Classic
2. i try to check the .NET framework 3.5 (include .net 2 and 3) on Windows features on/off
the error:
Detailed Error Information:
Module StaticFileModule
Notification ExecuteRequestHandler
Handler StaticFile
Error Code 0x80070032
Requested URL http://localhost:80/WS_TEST_SETUP/Service1.asmx
Physical Path C:\inetpub\wwwroot\WS_TEST_SETUP\Service1.asmx
Logon Method Anonymous
Logon User
Anonymous
Before I go back to Windows-7 what i can do ?
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hello
is what is possible when one selects one word in a textbox, every similar word will be displayed in a MessageBox.Show.
The principle is to retrieve those similar words and the user can see.
thank you
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Of course it's possible! The problem is how do YOU define "similar". Once you have that, YOU have to write the code to get the currently selected text in the textbox, then search the textbox contents for the "similar" works.
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can you help me in this code ?
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Nope. I've got my own pile of code to write and I'm not getting paid to write yours too.
You first need to define exactly what you mean by "similar" and then probably do some research on "Regular Expressions".
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When I try to serialize an object using xmlserializer,It is throwing out of memory exception.Is there any way to serialize large objects like more than 30 mb. I am able to serialize an object to xml file only if the size of the file after serialization is around 15 mb otherwise outofmemory exception is thrown
modified 11-Nov-12 2:53am.
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We got an article[^] on the subject. Unless you'd really need it as XML, I'd also recommend using the BinaryFormatter.
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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.
modified 10-Nov-12 17:16pm.
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ASPnoob wrote: with the sealed modifier
You missed this in your understanding, sealed means, well sealed!
Never underestimate the power of human stupidity
RAH
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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.
Alan.
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Thank you all for responding. I guess the confusion was over the fact that the author of the article was not being very clear.
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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.
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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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).
using System.Configuration;
public esampleDataContext() :
base(ConfigurationManager.ConnectionStrings["sample.Properties.Settings.DEVConnectionString"].ConnectionString,mappingSource)
**Note: base(global::sample.Properties.Settings.Default.DEVConnectionString, mappingSource) is the line of code that I replaced that was generated by the
.net framework
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.
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rachel_m wrote: 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.
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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.
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rachel_m wrote: ConfigurationManager.ConnectionStrings
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.
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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
tbhattacharjee
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I found that reports tend to grow, usually AFTER the application has been deployed and has been used for some time. Also if you have different customers they often want distinct reports.
I had all my reports in a table, all records had a stored procedure name and a file name, if the file existed and the procedure existed the report could execute.
I could then distribute a new report without having to recompile and distribute the app. Simple deliver the file and a script to create the stored procedure and report record.
Never underestimate the power of human stupidity
RAH
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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
tbhattacharjee
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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.
Never underestimate the power of human stupidity
RAH
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