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What is the result of a query in c# when is false or is true
for example i have the following query and i want to do something when is false. How i manage this?
string rfyear = ((string)cmd_year.ExecuteScalar());
i want to manage with "if" if i can to do something like this...
if (rfyear.Length == 0) { MessageBox.Show("the query is false "); }
else{ MessageBox.Show("OK");
textBox1.Text = rfyear;
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It all depends on what your query is actually returning: it is very possible that your line:
string rfyear = ((string)cmd_year.ExecuteScalar()); Will not work, but throw an InvalidCastException because the data coming back can't be cast to a string - it may work if you change it to:
string rfyear = cmd_year.ExecuteScalar().ToString(); But...I wouldn't recommend it as there is a very good chance that you will get a string containing the name of the type of the value returned.
What does your query return when it works and when it fails?
The universe is composed of electrons, neutrons, protons and......morons. (ThePhantomUpvoter)
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I just came to know about the Linux tracing tool mechanism available in Java (LTTng - Linux Tracing Toolkit Next Generation).
It actually is a framework that provides analysis of traces and events on a linux machine.
I want to develop a windows application which will read linux traces(usually in CTF format - common Trace Format) from a file and decode the value and time of trace. This application runs on Windows PC.
Can any body suggest me the best possible approach for this?
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If I were looking to do this, I'd first of all look to see if anyone had already written code that did this; if they hadn't, I'd then look at the specifications[^].
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I've made an application that works with SQL database. Now want without install the software SQL on client computer ,an applicationto work.
what way do you suggest?
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Use a different database, like SQLite. SQL Server must be on the client computer, or the client computer must be able to connect to the SQL server remotely, it doesn't run without the back-end installed on something that it can talk to.
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Ron Beyer wrote: or the client computer must be able to connect to the SQL server remotely, it doesn't run without the back-end installed on something that it can talk to.
Thanks for the Answer
Can you explain more about connecting remotely, step by step
Thanks...
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I think you are not talking about web application. In web application DB will setup in SQL server. For a desktop application sql server is not a recommended DB. You have setup SQL server in client machine also for desktop app
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manu v nath wrote: For a desktop application sql server is not a recommended DB.
Yes, it is. As soon as multiple users need access to the data, we use a real database-server. A local database-file (SQLite, MSAccess) is only recommended if the data remains local and doesn't need to be shared.
manu v nath wrote: You have setup SQL server in client machine also for desktop app
No, one has to install Sql Server. The client only needs access to the server-application. That might be a server that's shared among multiple clients as well as a local server that's only used locally.
Bastard Programmer from Hell 
If you can't read my code, try converting it here[^]
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For the installation of a C# desktop 2010 application, I am using the traditional setup and deployment template.
As part of this template, I want to make certain that a folder is created in a directory path that looks like
C:\log_files.
Thus can you tell me how to have the setup and deployment project create the directory path for me, if the directory path does not exist?
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I'm not sure about VS2010 as I am still using VS2008, however in the setup project, open the primary output file and click on the 'File System on Target Machine'. There you can add a 'Custom Folder' through the right-click menu. Name the new folder whatever you want, and then click on properties for the new folder and set the default location to the directory path you want to use.
Having said that, if this is a folder that your application is going to use during runtime, I would highly recommend that your application check for the existence of the folder and create it if needed before writing the "log files" to it (see the System.IO.Directory class). For instance, will your application crash if after it is installed the user then deletes the "log files" folder?
Also, keep in mind that not all users may have permissions to create folders on the C:\ drive. I've run into that issue with Windows7 several times and the permissions we use. You may need to come up with a work-around or use a user's folder instead.
-NP
Never underestimate the creativity of the end-user.
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Hi All,
I created a ClickOnce application, but if I upload it to download sites, they sometimes have problems processing it. For example, they install (copy) the .application file instead of running it.
So what I want to do, is create a ClickOnce application downloadable from my website, and apart from that build an installer around it so it can also be installed via an .msi.
After installing I would like it to behave like a ClickOnce application, that is autmatically checking and updating from the website.
However, I do not know all the ins and outs of both technologies, so I don't know if this is possible.
Any help or suggestions would be nice.
Thanks in advance,
Mathijs Beentjes.
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You could always avoid ClickOnce altogether and serve the files via an automatic update facility - Application Auto-update via Online Files in C#[^]
“That which can be asserted without evidence, can be dismissed without evidence.”
― Christopher Hitchens
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Hi experts,
a software I made provides the user with a PropertyGrid[^] to change certain values. Some of them are enum-based.
Customer doesn't like to be forced to click twice: first to open the UITypeEditor[^], second to choose the value.
Customer would rather want to have possible values constantly displayed as RadioButton[^]s. (See this illustration[^].)
Is PropertyGrid that customizable to draw a property as something other than $PropertyName and $PropertyValue as one-line-texts?
Is there some OwnerDraw possibility I didn't recognize?
Is there a third-party control that supports that (this[^] looks nice but User still has to pull the editor down)?
Ciao,
luker
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lukeer wrote: Customer doesn't like to be forced to click twice
There's an example on a fully custom inline editor in one of the CodeProject articles[^].
Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
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But it still shows a value as one line. At least I haven't found a way to create multi-line visualizations of multiple-choice options.
Ciao,
luker
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lukeer wrote: But it still shows a value as one line.
That's what the PropertyEditor dictates; one property per line. You can "unfold" some of the properties (try the Font property in a WinForm as example), but that's as close as it gets.
Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
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Hi,
I have a requirement where I need to lock a object to get data from service. If service takes more time to response due to some reason, after 2 mins of timeout period it gets timed out and then lock gets released. Till that time all the other requests has to wait. In this way, During this abnormal service behavior, all the request has to be in waiting stage. First request will take 2 mins to release the lock and second one would then take 2 more mins (total 4 mins idle time) and third will take another 2 mins and so on. After some time, due to this, application will be hanged.
Now I want a technique where first request will acquire lock and get the response. All the other request should be waiting for this and once first request release the lock, this response should be assigned to all other pending request (as the output response will be same) and make them all released at the same time.So ultimately, all request will get a response in two mins and only one service hit will happen.
Do we have any technique in C# to achieve this?Anybody can help me to fix this?
Cheers
A.M.Jegan
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Sounds like a Queue<Request>, with a loop handling a request. Execute the method that handles the request async, wait until it returns or two minutes pass. When done, fetch next and repeat.
amjegan wrote: all request will get a response in two mins and only one service hit will happen.
Not if it works as you described; if there's three items in the pipeline that will timeout, total waiting-time for the next request will be >6 minutes.
Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
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amjegan wrote: Now I want a technique where first request will acquire lock and get the
response. All the other request should be waiting for this and once first
request release the lock, this response should be assigned to all other pending
request (as the output response will be same) and make them all released at the
same time.So ultimately, all request will get a response in two mins and only
one service hit will happen.
And then what happens in the following scenario?
- First request times out.
- Second request succeeds.
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We don't worry about whether it succeed or failed as the data we are pulling is not affect the mainstream of the application. Application can still be running. Only thing is it should not be waited long time to get response. Thanks!
Cheers
A.M.Jegan
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Have you considered reducing the timeout significantly.
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Hi,
I want to read data from MMF File in c#.net framework 3.5
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Same question applies to the NSF question, what is an MMF file, if it is a notes specific file then the same answer applies as well.
For any file type that is proprietary you will need to get the format/api from the owner and some types are just not available.
Never underestimate the power of human stupidity
RAH
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