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System.IO.FileStream
If it is an assignment this class will cover all of your bases the quickest.
Need a C# Consultant? I'm available.
Happiness in intelligent people is the rarest thing I know. -- Ernest Hemingway
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humblepgmr wrote: I'm learning C# and have been given an assignment with a flexible requirement of reading / writing to a file.
Umm... reading and writing what? The .NET BCL provides good support for serialization.
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Does this[^] article help?
/ravi
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hi,
im using a ultragrid to show and update data from sql server. bad i get the following error when i want to update the database:
Update requires a valid UpdateCommand when passed DataRow colletion with modified rows.
this is the code to update the data:
myconn = new SqlConnection(ConnectionString);
myconn.Open();
dataadapter.Update(datatable);
somebody any idea?
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Use dataset to update the data.
load dataset by dataadapder, then update it
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u mean instead of datatable using a dataset? i did it as follow bud stil the same error 
loading:
myconn.Open();
comm_imp.ExecuteNonQuery();
adapter.Fill(dataset);
datatable = dataset.Tables[0];
ultraGrid1.DataSource = datatable;
updating:
myconn = new SqlConnection(ConnectionString);
myconn.Open();
adapter.Update(dataset);
myconn.Close();
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The error message is self-explanatory. There is something wrong with the UpdateCommand for your DataAdapter. You haven't provided details of what your UpdateCommand is however. You would need to explain how you have set this up if you want further help.
Paul Marfleet
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There are two possibilities.
The first is that you setup your DataAdapter using an SQL Select command, but you didn't supply the Update, Delete, Insert SqlCommands to it. Or, you didn't use an SqlCommandBuilder object on the DataAdapter to have it fill in the remaining commands.
The second is that you did the stuff in the first paragraph, but the SQL Select command you gave it returns data from multiple tables. The DataAdapters will only work with single table queries if you want to call its Update method.
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Hi buddies,
Is it possible to place tab control on main menu? I tried it on VS 2003. But it doesn't allow to place it on main menu.
Please help me...
Thanks
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No, it is not possible using the built-in controls. You may be able to build a custom menu item that looks like a tab. That seems a little strange though; are you thinking more along the lines of an Office Ribbon control?
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After a lot of work I finally figured this out, turns out it's very simple.
I wanted to publish this as an article, but the submit wizard would not let me, it said it was too short. I could pad it, but I don't have time for that kind of *&^$.
Here it is:
<br />
<br />
try<br />
{<br />
lblRevision.Text = System.Deployment.Application.ApplicationDeployment. \<br />
CurrentDeployment.CurrentVersion.ToString();<br />
}<br />
catch<br />
{<br />
lblRevision.Text = "Debug";<br />
}<br />
-Matt
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I think that's a bit too simple for an article. Plus, it leaves out crucial information (this only works if you're deploying via ClickOnce technology) and it has some bad practices (it catches a general exception).
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Hi,
I am a student and doing a project on "serialization and deserialzation of a hashtable content " and the primary pbjective is to use XML serializer to achieve this task as we will be dealing on multiple platforms. Since XMlserializer doesnt work with hashtables I am trying to add the hashtable contents to arraylist(as I will be storing multiple datatypes) and then serialize the arraylist. But I am having trouble adding the keys and value from hashtable to arraylist...WOuld someone please help me as I am stuck at this point...\\
Cheers
Lokesh
Now here is the piece of code snippet for serializing
static void serialize()
{
System.Int32 i = 26;
System.DateTime j = System.DateTime.Now;
System.String k = "this is a test";
System.TimeSpan l = System.TimeSpan.MaxValue;
//I have declared serializedhashtable as new hashtable in one of my class
group1.serializedhashtable.Add("0", i);
group1.serializedhashtable.Add("1", j);
group1.serializedhashtable.Add("2", k);
group1.serializedhashtable.Add("3", l);
// Create an instance of an array, and copy the content of
// the hash table to this array
ArrayList myarray = new ArrayList();
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Hi!
You can iterate through the items in a Hashtable using foreach:
foreach (DictionaryEntry ent in group1.serializedhashtable)
{
myarray.Add(ent);
}
Oh, and by the way, your assignment for 'i' is wrong. It should be 42, not 26  .
Regards,
mav
--
Black holes are the places where God divided by 0...
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Thanks for reply Mav. I had tried that before with
foreach (object obj in group1.serializedhashtable)
{
myarray.Add(obj);
}
But then when I try to serialize the arraylist I get an error "There was an error generating the XML document.".Here is the code snippet
// 'Open a filestream to write the contents
FileStream filest = new FileStream("newhashtable.txt", FileMode.Create);
XmlSerializer xs = new XmlSerializer(typeof(ArrayList), new Type[] { typeof(System.Int32), typeof(System.DateTime), typeof(System.String), typeof(System.TimeSpan) });
xs.Serialize(filest, myarray);
filest.Close();
Here are the exception details.
--------------------------------------------------------------------------------------------
System.InvalidOperationException was unhandled
Message="There was an error generating the XML document."
Source="System.Xml"
StackTrace:
at System.Xml.Serialization.XmlSerializer.Serialize(XmlWriter xmlWriter, Object o, XmlSerializerNamespaces namespaces, String encodingStyle, String id)
at System.Xml.Serialization.XmlSerializer.Serialize(Stream stream, Object o)
at Module1.serialize() in D:\Project\actual csharp solution\Program.cs:line 96
at Module1.Main() in D:\Project\actual csharp solution\Program.cs:line 42
at System.AppDomain.nExecuteAssembly(Assembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
--------------------------------------------------------------------------------------------------------
Thanks you,
Lokesh
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In contrast to this if I add these variables directly into the arraylist(instead of copying them from hashtable) I can generate the XMl document without any errors.
For eg: If I add the variables directly into the array..then its no problem
myarray.Add(i);
myarray.Add(j);
myarray.Add(k);
myarray.Add(l);
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I am writing a WPF application which shows video content.
The PC will run 24 hours a day and is protected from power loss by a UPS. If the mains power goes down for over a minute, the UPS software sends the PC into hybernation. When the power is restored the PC resumes, however... The application which was showing the video now shows nothing (blank space).
Is there a way of detecting the immanent hybernation in order to gracefully stop the videos, and restart them or the application when the PC resumes?
gmar
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Looking at Microsoft.Win32.SystemEvents.PowerModeChanged might help.
xacc.ide
The rule of three: "The first time you notice something that might repeat, don't generalize it. The second time the situation occurs, develop in a similar fashion -- possibly even copy/paste -- but don't generalize yet. On the third time, look to generalize the approach."
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Thank you that is definitely worth looking up.
gmar
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I have a log-in window application. When the user presses the cancel button it kills another window by it's name and then it exits. The problem is that if somebody kills the log-in window by terminating the process in the task manager the other window is not killed.
One solution might be to have a surveillande thread which doesn't die when the mother-thread dies, and can't be killed in the task manager. As soon as the log-in window thread stops responding to surveillance messages it will kill the other window and then exit.
Is this possible?
I've also tried to have a form which spawns another form, but in the Task Manager there is only one entry (PasswordDialog.exe). If you kill this process everything dies and the window which I want to kill when the log-in window dies is not killed.
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check the IsBackGround property of thread..............
My small attempt...
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Doesn't work, window remains. I set IsBackground to true.
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Implement the surveillance functionality as a windows service. That way you can easily let it run from a privileged account and a non-admin user won't be able to kill these processes.
Regards,
mav
--
Black holes are the places where God divided by 0...
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Hi buddies,
There are lots of small size picturebox on one picturebox control says picMain.At a time, I am moving only 1 picture on picMain on Mouse_Move event. But,I see problem with moving picture. Moving picture gets blur or I can say It need some re-draw.
so,I have use Invalidate() and update() to make the solutions but not getting any solution.
Instead of picMain if I try same thing on form, then it work very smoothly.I think picture box take more time to re-draw compare to form.
Pls help !!!
Regards
Chintan
www.visharadsoft.com
(I am thinking to change humans to computer, but unfortunately GOD will not give me the source code)
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I'm not sure what help you need. You've worked out the answer I would give, don't use pictureboxes, pretty much ever. Just draw the image yourself.
Christian Graus - Microsoft MVP - C++
"also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )
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