|
User machine had .NET framework version 1.0 on his machine. Later after it was updated to version 1.1, my application started to behave erratically.
The main erratic behaviour was in firing of event.
When the form loads, I programmetically sets the selectedIndex for ComboBox, which then fires SelectedIndexChanged event. This was the normal behaviour.
But now setting the selectedIndex for ComboBox programmetically doesn't fire the event.
When I go to help-->About in ".Net Framework development environment" I see the version 1.0 (1.0.3705), which means appliction was built on version 1.0.
Target machine has both 1.0 and 1.1, and from Micrsoft website I found that application built using 1.0 deafult to 1.0 framework.
http://msdn.microsoft.com/netframework/technologyinfo/versioncomparison/default.aspx[^]
Any pointers for this erratic behaviour
|
|
|
|
|
Yes, the frameworks do run side by side and your application will use the version it's built against if available. If not, it will use a newer one or whatever you configure as a supported runtime in your app.config file.
If your application is behaving eratically, it's possible that 1.1 was not installed correctly, but I've only seen this when installing in reverse order (doesn't happen all the time, but seems pretty common). You might want to add code in your application (even if all it doesn't is use the DefaultTraceLister a la Trace.WriteLine) to list the assemblies currently loaded into your default AppDomain, along with their versions. Version 1.0.3705.0 (hopefully .228, which is 1.0 SP2) is .NET 1.0 and 1.0.5500.0 is 1.1.
As far as the specific event problem you mentioned - are you sure this is the same codebase? The event hasn't changed from one version to the other, nor will it most likely (for backward compatibility).
The only other thing I can think of is that something else was hosed on this system. The Windows Forms controls encapsulate the Windows Common Controls (native controls). If the machine got screwed up somehow - though you'd most likely notice in other applications - the controls might not work correctly, and would most likely fail all together.
Microsoft MVP, Visual C#
My Articles
|
|
|
|
|
On my machine I tested the application by modifying <appname>.exe.config file. When I force it to go to version 1.1, it gives the same erratic behaviour (i.e. not firing SelectedIndexChanged event)
<code><startup>
<supportedRuntime version="v1.1.4322" />
</startup> </code>
So to me it looks like, it is backward compatibility issue. For now I will include following in <appname>.exe.config file on client machine.
<startup>
<supportedRuntime version="v1.0.3705" />
</startup>
If really this is an issue (and not something that I am missing), it will lead to compatibility problms.
Thanks Heather for your feedback
Ruchi
|
|
|
|
|
"Heath", actually.
This is odd. That behavior shouldn't have changed. It's still supported and I highly doubt the related IL for firing the event works differently, since few changes were made from 1.0 to 1.1, and most were for performance reasons. What does your event handler hook-up and handler method look like?
Microsoft MVP, Visual C#
My Articles
|
|
|
|
|
One of my doubts that it was built using 1.0, and why is it not to going to 1.1 version has been confirmed. Actually IT support team, uninstalled 1.0 and then they installed 1.1, that's why upon not finding the default version application goes to 1.0.
When the form loads, I fill the combobox, and then set the selecetdIndex on that combobox by following code
cboCompany.DataSource =null;
cboCompany.DisplayMember = "CompanyName";
cboCompany.ValueMember = "CompanyCd";
cboCompany.DataSource = m_dscompanydeskbook.Tables["Company"];
cboCompany.SelectedIndex=GetSelectedIndex(cboCompany, "CSC", "CompanyCd");
And there is one event
private void cboCompany_SelectedIndexChanged(object sender, System.EventArgs e)
{
}
which is supposed to fire upon getting past this line:-
cboCompany.SelectedIndex=GetSelectedIndex(cboCompany, "CSC", "CompanyCd");
Thanks
Ruchi
|
|
|
|
|
It will only fire if you've hooked-up the event:
cboCompany.SelectedIndexChanged +=
new EventHandler(cbo_Company_SelectedIndexChanged); If IT uninstalled 1.0, then they're dumb (go figure). Your app should still work under 1.1, however, as long as you don't use any deprecated classes, methods, etc.
Microsoft MVP, Visual C#
My Articles
|
|
|
|
|
Hi,
I'm trying to create a RSS News Aggregator, and this is part of code for it:
private void Page_Load(object sender, System.EventArgs e) <br />
{ <br />
string strFeedID = Request.QueryString["FeedID"]; <br />
int feedID = 0; <br />
<br />
if (strFeedID != null) <br />
{ <br />
feedID = Int32.Parse(strFeedID); <br />
} <br />
<br />
<br />
XmlDocument feedXML = (XmlDocument) Cache["Feed" + feedID]; <br />
if (feedXML == null) <br />
{ <br />
OleDbConnection myConnection = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\\Inetpub\\wwwroot\\SyndicationDemo\\RSS.mdb"); <br />
string SQL_QUERY = "SELECT URL, UpdateInterval FROM Feeds WHERE FeedID = @FeedID"; <br />
OleDbCommand myCommand = new OleDbCommand(SQL_QUERY, myConnection); <br />
<br />
OleDbParameter feedParam = new OleDbParameter("@FeedID", OleDbType.Integer, 4); <br />
feedParam.Value = feedID; <br />
myCommand.Parameters.Add(feedParam); <br />
<br />
myConnection.Open(); <br />
string feedURL = ""; <br />
int updateInterval = 0; <br />
<br />
OleDbDataReader reader = myCommand.ExecuteReader(CommandBehavior.CloseConnection); <br />
reader.Read(); <br />
try <br />
{ <br />
feedURL = reader["URL"].ToString(); <br />
updateInterval = Int32.Parse(reader["UpdateInterval"].ToString()); <br />
} <br />
catch <br />
{ <br />
feedURL = "default url"; <br />
updateInterval = 0;
} <br />
myConnection.Close(); <br />
<br />
feedXML = new XmlDocument(); <br />
feedXML.Load(feedURL); <br />
<br />
Cache.Insert("Feed" + feedID, feedXML, null, DateTime.Now.AddMinutes(updateInterval), TimeSpan.Zero); <br />
<br />
} <br />
<br />
xmlNewsItems.Document = feedXML; <br />
<br />
XsltArgumentList xsltArgList = new XsltArgumentList(); <br />
xsltArgList.AddParam("FeedID", "", feedID); <br />
xmlNewsItems.TransformArgumentList = xsltArgList; <br />
}
____________________________________________________
I am receiving this error when I try run it:
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. <br />
<br />
Exception Details: System.IO.FileNotFoundException: Could not find file "C:\WINNT\system32\default url". <br />
<br />
Source Error: <br />
<br />
<br />
Line 77:
Line 78: feedXML = new XmlDocument(); <br />
Line 79: feedXML.Load(feedURL); <br />
Line 80: <br />
Line 81: Cache.Insert("Feed" + feedID, feedXML, null, DateTime.Now.AddMinutes(updateInterval), TimeSpan.Zero); <br />
<br />
<br />
Source File: c:\inetpub\wwwroot\syndicationdemo\display.aspx.cs Line: 79
____________________________________________
I have been racking my brain to find a solution, but haven't been able to.
Can someone out there please help me.
Your help will be greatly appreciated.
Thanks!!
|
|
|
|
|
The exception is pretty obvious: the path you're requesting can't be found. When you want to load a file, you must use the physical path - not the URL. In ASP.NET, you can use MapPath (implemented on the Page and HttpServerUtility (the Server property that many classes expose)) to map a virtual path (i.e., URL) to a physical path on the same machine:
feedURL = MapPath("default url");That'll get you the physical path to the file which you can load into your XmlDocument.
Microsoft MVP, Visual C#
My Articles
|
|
|
|
|
Hi,
Thanks for your feedback.
This section of the aggregator should initially display a blank page, and not anything else (including any other URL's). Do you know how I could go about rectifying that?
Thanks once again 
|
|
|
|
|
1. Set all controls' Visible properties to false that you don't want displayed.
2. Override Render in your page and don't render anything initially.
3. Redirect to a blank page.
4. Transfer execution to a blank page.
5. ...
There's countless ways.
Microsoft MVP, Visual C#
My Articles
|
|
|
|
|
Thanks Heath
|
|
|
|
|
Im having a lil problem with some code. I think it would be better to explain it then post it. Im using a thread timer to run a blaock of code that checks if the computer is online using try catch statements. It run good when online but when i go offline it runs some code (catch statement) but doesnt keep checking if online, as in the thread timer stops when the exemption is thrown. Is there a way to have the program keep checking if its back online, without forever loops (which didnt work out right, still learning C#)
Outline:
thread.Timer(timerCallBack( ON_TIMED_EVENT )) //every 60 sec
ON_TIMED_EVENT
{
try
{
check if online
IPHostEntry hostInfo = Dns.GetHostByNam
}
catch Exception
{
code when not online
}
}
I want it to keep checking instead of just stoping the
Thread Timer
Jason
modified 16-May-21 21:01pm.
|
|
|
|
|
Which Timer class are you using? There's three different ones and they all work a little differently.
Microsoft MVP, Visual C#
My Articles
|
|
|
|
|
System.Threading.Timer
modified 16-May-21 21:01pm.
|
|
|
|
|
First question to ask is does the ON_TIMED_EVENT ever return?
Maybe there is something wrong with your code in the catch statement.
|
|
|
|
|
It doesnt return anything just checks to see is my computer is online by pinging a website. This is on a timer that repeats every 60 secs (testing it on every 5 secs). When i disconnect the catch block is ran but thats it, doesnt check anymore if online or offline, this is what im trying to fix, to keep checking even after the catch(Exception), im thinking about using "finally" since it always runs if a try or catch is ran, i just now thought of it.
modified 16-May-21 21:01pm.
|
|
|
|
|
"finally" didnt work, it looks like after the catch the Thread.Timer stops running, so the On_Timed_Event doesnt run anymore.
modified 16-May-21 21:01pm.
|
|
|
|
|
Then apartently your not catching exceptions in the right place or aren't catching the right exceptions. I know you put Exception in your sample code in the root message of this thread, but I've seen many times where people don't sample their code accurately.
The other problem is that all the timers (and pretty much everything in System.Threading) encapsulate native APIs. If a thread throws an exception in the native API, the timer thread will most likely quit. In your catch block, restart the timer by instantiating a new Timer, assigning it to the previous field (if any) and using the same TimerCallback delegate.
Also, you should consider using System.Timers.Timer instead, which has higher resolution and is pretty well guarded against exceptions (it still throws them, but typically recovers the timer thread).
Microsoft MVP, Visual C#
My Articles
|
|
|
|
|
Thanks, using System.Timers.Timer works.
modified 16-May-21 21:01pm.
|
|
|
|
|
I am trying to develop an custom listView that can be viewed in Windows XP and 2003 in GroupView ( Explorer-like ). This listView will have 2000+ items. The problem is that when it has 2000 items, it works very very slow. I've tried to set LVS_OWNERDATA and it increases the speed dramatically, BUT LVM_ENABLEGROUPVIEW is not supported with virtual listViews. The real question here is how you can make a listView very fast ( i mean not loading the items, fast when you browse through them ) , without setting LVS_OWNERDATA . My personal opinion is that this is a major bug in WindowsForms( the fact that it is so slow ) cause I tried the same thing in MFC and works fine. Please help me and possibly others who are dealing with this. Thanks in advance !
|
|
|
|
|
It's not a bug in Windows Forms (i.e., the .NET FCL) - it's just how the CLR passes messages around and encapsulates everything, since all those controls just encapsulate their Common Control equivalents. Even most of the painting is handled by the List-View common control itself. I'm assuming you're overriding WndProc in your derivative class (since that's about the only way to do it), so make sure you keep the code fast by using conditionals right away to determine if you even want to handle the message. If you still handle owner-drawing by creating Graphics objects, then you'll incur quite a performance penalty as managed objects are being created that encapsulate native handles. In this case, you'll probably be better off P/Invoking the GDI functions you need to do any painting.
Not that it really helps now, but the .NET Framework 2.0 will introduce both grouped views and virtual lists. I haven't tried grouping with thousands of items, but I'd assume its pretty fast since I know Microsoft is focusing on better performance in 2.0.
Microsoft MVP, Visual C#
My Articles
|
|
|
|
|
Thanks for your reply. Even if I don't override WndProc at all and just create a listView with 2000 items, it's still slow when you're browsing the last items in the list. I've tried text and/or image callbacks but still doesn't help. Any ideea ? ( besides using a ListBox ) . By the way, when will .NET Framework 2.0 will be released ?
|
|
|
|
|
I'm sorry, but without seeing your code its hard to know what to suggest. Unfortunately, I really don't have the time (really).
The .NET Framework 2.0 is supposed to be out early in 2005 (haven't heard which quarter yet, though, despite my connections - because they don't know either). It's delayed primarily because of SQL Server 2005 (formerly code name "Yukon"). They want to release them at the same time since they're basically companion products.
Microsoft MVP, Visual C#
My Articles
|
|
|
|
|
Hi new to programming. I have a program that is supposed to compare two dates however when I run the program it reads the date as a string. What is the best way to compare a date to another date?
|
|
|
|
|
Use DateTime.Parse to parse a string into a DateTime (be sure to catch exceptions) and use DateTime.Equals or == to compare it to another DateTime. If you only want to account for the date portion of a DateTime, then compare one DateTime.Date to another. Same goes for DateTime.TimeOfDay (which is actually a TimeSpan structure). See the .NET Framework SDK for more information.
Microsoft MVP, Visual C#
My Articles
|
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
