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Are you talking about menu items with CheckBox's ?
Something this simple might help:
menuItem3.Enabled = (menuItem1.Checked && menuItem2.Checked && ...);
Enjoy,
David
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Hi.
No, what I mean is to have a menuItem like Paste grayed out unless you have something on the clipboard, one can´t paste unless something is on the clipboard. Once you have something on the clipboard Paste becomces selectable, not grayed out. I want certain menuItems to be grayed out if some other menuItem is selected.
Thanks,
FJ
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Hi!
You can use the menu's Popup event to enable/disable the menu items of your menu, so if you have a menu myMenu you could write the Popup event handler like this:
private void myMenu_Popup(object sender, EventArgs e)
{
myMenuItem1.Enabled = SomeFunctionToDecideWhetherMenuItem1IsEnabled();
}or, using the clipboard example:
private void menuEdit_Popup(object sender, EventArgs e)
{
DataObject dob = Clipboad.GetDataObjet();
menuEditPaste.Enabled = dob.GetDataPresent(DataFormats.Text);
}Regards,
mav
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Hi, thanks for your help.
I still don´t know how to do this. How can I disable a menuItem when some other menuItem is selected? For instance, if menuItem5 is chosen then I want menuItem11 and menuItem12 to be disabled? How do I do that?
Thanks again for your help,
FJ
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private void menuItem5_Clicked(object sender, EventArgs e)
{
menuItem11.Enabled = false;
menuItem12.Enabled = false;
}that's as explicit as I can put it...
mav
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Hi.
This is very clear!! Vielen Dank!
Take care,
FJ
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Search for an ActionList component on codeproject, this should help you.
'A programmer is just a tool which converts caffeine into code'
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I want to display the status in a ProgressBar when copying large files across the network. I am using FileInfo.CopyTo method within the DoWork Method of the BackgroundWorker class (please see the code below). How am I able to fire events while the copying is taking place to update the ProgressBar. The problem is that the execution enters FileInfo.CopyTo method and does not leave until the process is complete.
Hope this makes sense.
private void backgroundWorker_DoWork(object sender, DoWorkEventArgs e) {<br />
<br />
BackgroundWorker worker = sender as BackgroundWorker;<br />
reached = 0;<br />
fileInfoFrom = new FileInfo(@"C:\Temp\Path1\Test.zip");<br />
fileInfoTo = new FileInfo(@"C:\Temp\Path2\Test.zip");<br />
<br />
<br />
fs = (fileInfoTo.Exists) ? fileInfoTo.Length : 0f;<br />
fileInfoFrom.CopyTo(@"C:\Temp\Path2\Test.zip", true);<br />
<br />
int completed =<br />
(int)((float)fs / (float)fileInfoFrom.Length * 100);<br />
if (completed > reached) {<br />
reached = completed;<br />
worker.ReportProgress(completed);<br />
}<br />
}
-- modified at 12:47 Sunday 4th December, 2005
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Well, the way I'd tackle it would be to implement the File Copy function myself. I could raise events with controlled frequency as I shovel the data from the source file to the new destination file.
Regards,
Rob Philpott.
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Do you know of any examples that I can take a look at?
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Hi,
I've cobbled together an implementation you can use to get you started. Please note this is rough and ready and has no Exception handling in it etc. Ideally, to do the job properly I'd implement a new class and provide BeginCopy, CancelCopy and EndCopy static methods as we are encouraged to do for asynchronous methods.
BTW - because you will launch the copy on a worker thread, make sure you switch thread before attempting to update your progress bar (use Control.BeginInvoke).
<br />
using System;<br />
using System.Collections.Generic;<br />
using System.Text;<br />
using System.IO;<br />
<br />
namespace ConsoleApplication1<br />
{<br />
class Program<br />
{<br />
static void Main(string[] args)<br />
{<br />
FileCopy(@"f:\BTSDev Hard Disk.vhd", @"c:\test.vhd", new UpdateProgressDelegate(RelayProgress));<br />
}<br />
<br />
public static void RelayProgress(int percentile)<br />
{<br />
Console.WriteLine("{0}% complete", percentile);<br />
}<br />
<br />
delegate void UpdateProgressDelegate(int percentile);<br />
<br />
static void FileCopy(string sourceFileName, string destinationFileName, UpdateProgressDelegate handler)<br />
{<br />
byte[] buffer = new byte[1024];<br />
<br />
FileStream fsInput = new FileStream(sourceFileName, FileMode.Open, FileAccess.Read);<br />
FileStream fsOutput = new FileStream(destinationFileName, FileMode.Create, FileAccess.Write);<br />
<br />
long totalLength = fsInput.Length;<br />
long readSoFar = 0;<br />
int percentile = 0;<br />
<br />
handler(0);<br />
<br />
int readThisBuffer = fsInput.Read(buffer, 0, 1024);<br />
<br />
while (readThisBuffer > 0)<br />
{<br />
readSoFar += readThisBuffer;<br />
int newPercentile = (int)((double)readSoFar / (double)totalLength * 100.0);<br />
if (newPercentile > percentile)<br />
{<br />
percentile = newPercentile;<br />
<br />
if (handler != null)<br />
{<br />
handler(percentile);<br />
}<br />
}<br />
<br />
fsOutput.Write(buffer, 0, readThisBuffer);<br />
readThisBuffer = fsInput.Read(buffer, 0, 1024);<br />
}<br />
<br />
handler(100);<br />
<br />
fsInput.Close();<br />
fsOutput.Close();<br />
} <br />
}<br />
}<br />
Regards,
Rob Philpott.
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Thank you, that makes sense. Do you think this method would be slower than the FileInfo or File classes? I am sure thaey use a very similar method within those classes.
Thank you once again. Will be implementing the method.
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Hi,
No problem, glad to be of help 
Performace wise I'd expect the Framework methods to have the edge as they use unmanaged Win32 calls behind the scenes (probably the reason asynchronous methods aren't provided for us). One thing you could do if the files you are copying are very big is to increase the size of the buffer from 1KB to say 8KB or more.
Regards,
Rob Philpott.
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I usually use special characters in many Form, in VS.NET i must use Advanced Save to change my Encoding. How i can change VS.NET 2003 to default encoding Unicode UTF 8 for all project? Thanks
Nothing
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Hi all,
I wanted to ask if it is possible to make the combobox only accept values from its dropdown options, because you can just enter some rubbish in the combobox and then I would have to check if the chosen input actually is a valid input(ie one from the options). Is there another way to do this or I would have to validate the input against the options?
Regards,
gamehack
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Yes, you can. Check out the ComboBox.DropDownStyle property.
"we must lose precision to make significant statements about complex systems."
-deKorvin on uncertainty
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Thank you
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My pleasure. Happy coding!
"we must lose precision to make significant statements about complex systems."
-deKorvin on uncertainty
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I was looking at some advanced code for learning experience. Can someone explain why a Dispose method would be used in classes? Is the destructor not good enough?
~RythmMachineApp()
{
Dispose();
}
public void Dispose()
{
if (Mixer != null)
Mixer.Dispose();
System.GC.SuppressFinalize(this);
}
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A Dispose method is used to make the object release any unmanaged resources. If you would put that in the destructor instead, the resources would no be released until the object is garbage collected.
---
b { font-weight: normal; }
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The reason is that you have zero control over when the "finalizer" (as the destructor is called in C#) is called.
If you have a class that has a Dispose method then you are supposed to call it when you are done with any object of that class. The Dispose method would normally close connections to external resources, free up unmanaged objects and so on.
You call Dispose from the finaliser in case the caller of the class did not clean it up properly. It also means that you only have one method where the clean up code resides.
You can have the language automatically called Dispose on objects with an IDisposable interface like this:
using (SomeDisposableObject obj = new SomeDisposableObject())
{
}
Does this help?
My: Blog | Photos
"Man who stand on hill with mouth open will wait long time for roast duck to drop in." -- Confucious
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I have an understanding now. I thought the redundancy with destructor and Dispose was odd, but now i see it is a way to have more control over the NET framework behavior.
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I was looking at some advanced code for learning experience. Can someone go over and explain the weird looking parts of the following code snippets?
SNIPPET #1
What is with the '?' and ':'?
public int GetBufferedSize()
{
return m_Player != null ? m_Player.GetBufferedSize() : 0;
}
lock(this)
{
return m_Playing ? this.Size : 0;
}
SNIPPET #2
What is with the 'this'?
public Track this[int ndx]
{
get
{
lock(m_Tracks)
return (Track)m_Tracks[ndx];
}
}
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?: is the ternary operator that is the equivalent of if/else
a?b:c ==> if(a){b}else{c}
Does this help?
My: Blog | Photos
"Man who stand on hill with mouth open will wait long time for roast duck to drop in." -- Confucious
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