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What defines a disabled item?
For the item's appearance you can owner-draw the items.
For the item's state you could use an item class that keeps its
enabled state.
The sample code here[^] seems like a good start 
Mark
Mark Salsbery
Microsoft MVP - Visual C++
![Java | [Coffee]](https://www.codeproject.com/script/Forums/Images/coffee.gif)
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Hi,
Since listbox items are objects they don't expose any special UI functionality. However the effect can be done by code by wiring SelectedIndexChanged-event and if the selected index should be handled as disabled, remove the selection.
However this isn't visual to the user since every item looks the same. There's no way of telling which is disabled and which isn't. Of course you can use owner drawn technique to make a different visualization, but that's not the only option.
What I would suggest is that you actually use ListView control instead. Since ListView contains ListViewItems, which are UI elements it's easier to control visual appearance by simply controlling Font and ForeColor. In ListView you also have to remove the selection when user clicks on an item. To do this, wire ItemActivate event and remove the selection if needed.
Hope this helps,
Mika
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In my app, there is a control that can be customized, so, I am trying to use the collectionedtior in order to do it.
It works fine.
Now, I am in toruble trying to update the control. When the user closes the collectioneditor form, I would like to get this event, and then, update the control which was customized.
I know how I can get the object which contains all information which was entered by the user in order to customize the control. But I don't know how I can get the OK button click event or something else which indicates that everything was done, and the control can be updated.
How can I get this event, and so, fire a notifier in order to update the control?
Thank you in advance.
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How do you invoke the collection editor form?
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I am building an object in my domain that looks like this:
DeviceMonitor
..public int Id
..public int GetCurrentValue()
I created an object in my DAL that will load it up
DeviceMonitorDao
..public DeviceMonitor GetById(int)
Everytime I call DeviceMonitor.GetCurrentValue() it should return a frequently updated value in the database. How should I seperate this concern into the DAL so that I am not coding it directly into the the Domain object?
Thanks a lot,
George Mauer
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Does The Star Trek game have to be in text play mode.
Or
Can i add graphics to it????
In other words should it be developed as a graphical game or text based game??
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How does it matter to me or any one else... 
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This should be posted in the suggestions and bug reports board to get official attention.
Today's lesson is brought to you by the word "niggardly". Remember kids, don't attribute to racism what can be explained by Scandinavian language roots.
-- Robert Royall
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Read the rules. You can do what you like with it.
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Summer Competition wrote: Use a technology you're an ace in. Or just use a technology that is absolutely inappropriate for the task and hand and bend it to your will.
The one that I started was using WPF with a humongous grid heirarchy with the use of gridlengthanimations (CP article). However, I have been so busy that I won't be able to complete it for the competition.
Regards,
Thomas Stockwell
Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning.
Visit my Blog
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Hi, I have searched through the articles but I am afraid I still do not quite get the event handing (custom events) in C#. I am new to C#, but a VB programmer for some years.
I have a class:
public class GPErrorArgs : EventArgs
{
private string sAppVerData = "Global Parameters Class";
private int nErrorCode = 0;
private int nErrorSection = 0;
private string sMessage = "";
private string sRoutine = "";
private string sSource = "";
private bool bCritical = false;
private bool bMustDisplay = false;
public GPErrorArgs(string ApplicationData, int ErrorCode, int ErrorSection, string ErrorMessage, string RoutineName, string ErrorSource, bool Critical, bool MustDisplay)
{
sAppVerData = ApplicationData;
nErrorCode = ErrorCode;
nErrorSection = ErrorSection;
sMessage = ErrorMessage;
sRoutine = RoutineName;
sSource = ErrorSource;
bCritical = Critical;
bMustDisplay = MustDisplay;
}
Various gets left out here to shorten the code in this request
public string RoutineName
{
get
{
return sRoutine;
}
}
}
I have a class which wants to use the error handling thus:
public class CGeneralParameters : IDisposable
{
private string m_strConnectionString = "";
private string m_sAppData = "";
private bool m_bDoneBefore = false;
public event ClassErrorEventHandler RaiseClassError;
public CGeneralParameters()
{
try
{
EMCServerParams cConnect = new EMCServerParams();
m_strConnectionString = cConnect.DBConnectionString;
cConnect.Dispose();
m_sAppData = "Global Parameters Class";
}
catch (Exception ex)
{
GPErrorArgs e = new GPErrorArgs(m_sAppData, (int)EnumSets.DeskTopErrorsEnum.dteSQLGeneralConnectionFailure, 1, ex.Message, "General Parameters:Initialisation", ex.Source, true, true);
OnRaiseClassError(e);
}
}
protected virtual void OnRaiseClassError(GPErrorArgs e)
{
RaiseClassError(this, e);
}
public object GetParameterByID(EnumSets.UserParameterNumbersEnum ParameterID)
{
object ParamReturnValue;
ParamReturnValue = GetAParameterByID((int)ParameterID);
return ParamReturnValue;
}
}
What am I doing wrong???
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the only thing I can see wrong is you're not checking the event for null (which will be the case if nothing has subscribed to the event.
protected virtual void OnRaiseClassError(GPErrorArgs e)
{
if(RaiseClassError != null)
RaiseClassError(this, e);
}
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Thanks, that maybe explains why it gets and exception when I run it. I will give it a whirl.
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Hi everyone
I am currently building an simple DJ pad with the use of the wiimote
I was using winamp to play my music, and my application to control winamp but i realised i wasn't complex enough.
Do you know any good DJ program that can be controlled via another application?
I am looking for some things to be able to be controlled via another application:
-Equalisator
-Next/previous song
-Volume
-Balance
Any Idea?
I really don't have time to code a complete media player...
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Hi all,
I need to interface with a third party system and they had this "genius" idea of using http posting. In other words, I send a command to their server over http as a long nasty URL to which hey then respond in the body of a HTML page (not even HTML formatted mind you, more like just plain text).
At any rate, that rant out of the way, let me get to my question.
I figured that an easy way to do this would be to simply put a Webbrowser on my form and navigate to whatever the URL is, override the Navigated() event, and proces the result in there.
The problem is that their server has a problem with its security certificate. I'm not too worried about the certificate but I am stumped by the Security Alert dialog box that pops up when I try to navigate to their URL asking me whether I want to proceed. It's easy enough for me to click on "Yes" but I don't want any user intervention to have to occur.
When I set the ScriptErrorsSupressed property to True, I don't get the dialog box anymore but the page then simply shows that "Navigation to the webpage was cancelled" with a link to refresh the page. By following that link (which I can do programatically but which is getting hairy already) I get another page giving me the message about the certificate having a problem and two links, one to close the webpage and one to continue o the website. I can now follow that second link programatically but in stead of giving me the third party response, I just get the certificate warning again.
Any ideas how I can get around this? And no, getting the third party to sort out their certificate doesn't seem to be a sollution.
While we're at it, isn't there perhaps another way of doing this that doesn't even involve a visual component to be dropped on the form? Also, I would have preferred if I could have a function that initiates the navigation to the URL and then only returns when the navigation is complete as opposed to this overriding of event handlers. Any ideas?
Thanks in advance.
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I'm facing some issues with the date thing:
While debugging, I can see that the value of stringDate is coming as "3/60/1989" (MM/DD/YYYY), which is practically not possible, but these value is coming from the database as it is wrongly entered there.
Now when this stringDate is parsed into DateTime format, it gives me a different date (i.e. the value of dtDate is shown as "6/30/1989") and throws an exception "Invalid DateTime Entry" at this line:
dtDate = DateTime.Parse(stringDate);
if (dtDate > startDate && dtDate < endDate)
{
row["NEW_DATE_FIELD"] = stringDate;
myTable.ImportRow(row);
}
So, now I want that my code to do the following: To enter a "INVALID DATE" message to the row["NEW_DATE_FIELD"] instead of the wrong date as such
Note : In VB.NET we have a built-in method named IsDate(), which receives a string as parameter and return True if the string is a date or false. Is there any short-cut method in C# equivalent to IsDate method ?
Any help would be appreciated.
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it's showing the compile error : 'System.DateTime' does not contain a definition for 'TryParse'
do i need to add any other namespaces or references.
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TryParse is only available in .NET framework 2.0 or later. If you are using version 1 then you would have to use the DateTime.Parse method and catch the FormatException when your input is invalid.
Alan.
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Thanks Alan, but that doesn't gives me solution to my problem.
If the date is invalid, i want the row entry to be message like this : "Invalid Date"
what shud be done in order to achieve this?
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Something like this then?
try {
dtDate = DateTime.Parse(stringDate);
if (dtDate > startDate && dtDate < endDate) {
row["NEW_DATE_FIELD"] = stringDate;
myTable.ImportRow(row);
}
} catch (FormatException) {
row["NEW_DATE_FIELD"] = "Invalid Date";
myTable.ImportRow(row);
}
Alan.
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Hi everyone
I have been programming in c# for some time now. Actually during a review of my code a question came up...
What is the most efficient way of creating public variables in an c# application that allows these variables to be globally accessible across the application?
I invite responses and views on the subject
Thanks in advance...
rome'
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I would suggest as Properties in a class
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thanks for your prompt reply...
to take this further...
would the properties be a part of a static class or a singleton object?
Thanks...
rome'
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Ive read that its more (memory) efficient to use a singleton class, but the exact logic eludes me at the moment. Personally I tend to take the lazy option and make it static. However Id avoid the whole issue entirely given the choice!
[Edit: a quick google turned up this: http://my.opera.com/zomg/blog/2007/09/17/singleton-pattern-vs-static-classes[^] which doesnt quite prove my point, but might be interesting reading for you]
modified on Tuesday, August 12, 2008 11:45 AM
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