|
I'm getting a null value.
There is no spoon.
|
|
|
|
|
Is your sender NULL or the casting failed? Step into the code and check what value sender has.
|
|
|
|
|
The casting gave me a null vaue.
That's really odd.
There is no spoon.
|
|
|
|
|
Hey guys,
Ive got a small program that communicates with an external fingerprint scanner, im using the manufacturers SDK via a dotNet wrapper. Now for this to work the DLL needs to be registered with the regsvr32 command.
Is there a way i can programmatically check that my DLL has been registered?
Thanks
Harvey Saayman - South Africa
Junior Developer
.Net, C#, SQL
you.suck = (you.passion != Programming)
|
|
|
|
|
RegistryKey clsid=Registry.ClassesRoot.OpenSubKey("CLSID");
string[] ClsIDs=clsid.GetSubKeyNames();
string subkey="";
for (int i=0; i<clsids.length;> {
subkey=ClsIDs[i];
if (subkey.Substring(0,1)!="{") continue;
RegistryKey cls=Registry.ClassesRoot.OpenSubKey("CLSID\\"+subkey+"\\InprocServer32");
if (cls==null) continue;
string x=cls.GetValue("","").ToString();
}
|
|
|
|
|
If it isn't, Activator.CreateInstance will throw an exception when you try to create an instance of a class from the COM library. There can be other reasons for the exception of course, so if you want to make sure it's the dll not being registered, you can check whether the registry key HKEY_CLASSES_ROOT\FullClassName is there (FullClassName being the string you pass to Activator.CreateInstance).
|
|
|
|
|
Hello everyone,
When we call a remote web services in an asynchronous way, we could return the invocation immediately and later we could either call Endxxx or our suppied callback will be invoked when the asynchronous call result is ready.
My question is, how will the result be delivered to client?
- Does the proxy on client side opens a port and listen to the return SOAP message containing the result?
- Does the client use keep alive technique and keeps the Http connection open/live from the beginning (when we call BeginXXX to invoke the web services) to the end (when the result is ready) -- if implemented in this way, there is no need for the client to open a port to listen?
- Or implemented in some other ways?
thanks in advance,
George
|
|
|
|
|
George_George wrote: My question is, how will the result be delivered to client?
As SOAP message.
George_George wrote: Does the proxy on client side opens a port and listen to the return SOAP message containing the result?
Communication is done using HTTP/HTTPS. So the port is 80 and proxy won't open it.
|
|
|
|
|
Thanks Christian,
So, how do you think asynchronous call is implemented especially when deliver results to client side and invoke callback at client side?
- Does the client (proxy) keep connection alive from beginning (when call BeginXXX) to end (when asynchronous callback is called)?
- or client continue to poll the result and retrive result from server side when it is ready?
- or something else?
regards,
George
|
|
|
|
|
Hey, I have successfully used Flash.ocx control in C# to play SWF movie file but I m facing some limitations in it. I jumped to any specific frameNo by using gotoframe() method given in this control, It do jumped but the problem arise when I try to jump on frame which is greater than 12,500 i.e: It only understands starting 12,500 frames of the movie although it do play frame grater than 12,500 but the problem is to jump. Do anyone has idea about this problem.
Plus I also want to play the movie at 1/2X,2X,4X,... speed, Is it possible using this control or I should look for another and what should that ANOTHER(remember I need it on windows form).
regards.
|
|
|
|
|
Hello All,
I have an MFC based MDI application (.exe) in which we created OLE
layer such that the application can be easily accessed by MS Excel and invoke
some of its properties.
Now we have a use case such as C# based DLL should be able to access this
already running MFC based application and invoke its properties or try to get
some data from the MFC application. Note C# DLL and MFC application are two
individual different processes. The C# DLL is being invoked by the MFC app it self. I think it should be a problem if the C# DLL is launched by MFC or its been invoked independently in either case i am looking for communication between these two.
Any suggestions in this.
thanks
|
|
|
|
|
venkyhyd wrote: I think it should be a problem if the C# DLL is launched by MFC or its been invoked independently in either case i am looking for communication between these two.
"I think it should NOT be a probelm if the C# DLL is launched by MFC or its been invoked independently in either case i am looking for communication between these two."
|
|
|
|
|
|
Hey folks,
I've been pulling my hair out on this one. I've got a data table that's created within the constructor for Form A (the child form). Now, this form is created from a button in Form B (the parent form), and can be done so multiple times simultaneously. I'm experiencing a peculiar problem where although Form A SEEMS to close fine (in the sense that it is fully destructed), the data table that was instantiated in that form wasn't disposed. I know this because I have a MessageBox.Show() within the constructor of Form A which displays some values from the data table. Each time the method is called, I'll have multiple message boxes depending on how many times I have opened Form A (regardless of how many times I've closed it!).
I've tried calling the dataTable.Dispose() method in the event handler for the closing of Form A and still this seems to do nothing.
I've no idea what's wrong  .
Any help is much appreciated.
|
|
|
|
|
Duy Pham wrote: I've tried calling the dataTable.Dispose() method in the event handler for the closing of Form A and still this seems to do nothing.
Then you have some design issue. Can you show us some sample code?
|
|
|
|
|
It's a fairly bulky program so I'll just paste over the instantiation of the objects.
EventHandler code within Form B (the parent form) which constructs Form A (the child form):
else if (radioButton_Inventory.Checked)
{
WindowInventory new_WindowInventory = new WindowInventory(
sqlconnector, sqlconn, inv_container);
new_WindowInventory.Activate();
new_WindowInventory.Show();
}
Now when Form B finishes being constructed, I use the _Load form event to stick in my code which assigns values to the data table.
private void WindowSales_Load(object sender, EventArgs e)
{
// ...
DataGridPopulator.PopulateWindowGrid_Sales(
partlist_array, ref dataTable_PartListing);
}
And then upon closing of Form B, I pass in these two lines:
dataTable_PartListing.Dispose();
this.Dispose();
Hope that helps. Thanks!
|
|
|
|
|
Why do you think that the data tables aren't disposed?
Despite everything, the person most likely to be fooling you next is yourself.
|
|
|
|
|
Say I open form B and close it 4 times successively. On the fifth time I open the form B, the messagebox.show() method will construct 5 message boxes with the values of 5 UNIQUE instances of the datatable. Which makes sense since I constructed 5 data tables that didn't seem to dispose of itself upon the closing of Form B.
Hope that makes sense.
|
|
|
|
|
I don't understand what you mean...
In the constructor of form A you create one data table and show one message box? If you open and close form B, how does that have anything to do with the message boxes?
Perhaps you mixed up the form A and form B? What about calling them something that makes sense?
Duy Pham wrote: On the fifth time I open the form B, the messagebox.show() method will construct 5 message boxes with the values of 5 UNIQUE instances of the datatable.
It sounds like you are doing something that you don't think that you do... A single call to MessageBox.Show can not result in five message boxes.
Despite everything, the person most likely to be fooling you next is yourself.
|
|
|
|
|
Treat Form B as a the child form and Form A as the parent form. I know this sounds really bizzare, and I don't understand myself either, but the number of message boxes that appear form a SINGLE instantiation of form B is always equal to the number of times I opened (by open I mean instantiate a NEW form B, the child form, assuming any previously open instance of Form B had been closed).
The MessageBox.Show() lies within a EventHandler that I personally created from a _Tick event from a System.Windows.Form.Timer object.
private void updateTimer_Tick(object sender, EventArgs e)
{
//...
string msg = "";
for(int i = 0; i < dataTable_PartListing.Rows.Count; i++)
{
msg += dataTable_PartListing.Rows[i][0].ToString() + " ; " +
dataTable_PartListing.Rows[i][1].ToString() + " ; " +
dataTable_PartListing.Rows[i][2].ToString() + " ; " +
dataTable_PartListing.Rows[i][3].ToString() + "\n";
}
MessageBox.Show(msg);
updateTimer.Start();
}
In the above code, updateTimer is the System.Windows.Form.Timer object. By any chance, does leaving that timer on while trying to close the form leave the instance of the form, and thus all objects instantiated within it, still active?
Thanks
|
|
|
|
|
Hi everybody,
i have a question in my project,i need your help.
The question :when i printed a barcode label in b/s system,the System components like 'PrintDialog' and 'PrintDocument' does not work.while i used it in c/s system,it was worked.So,i want to know how to solute it.
|
|
|
|
|
open http://www.commstudio.com/ , maybe it will be usefull fur you
|
|
|
|
|
I want a control where there's three options: On (White background with check), Off (grayed background, no check) and Neutral (white background, no check). Any ideas?
modified on Thursday, September 4, 2008 1:10 PM
|
|
|
|
|
Jordanwb wrote: grayed background
.Enabled=false;
|
|
|
|
|
But then it will not respond to events. AFAIK there is not a 3 state checkbox standard in VS.
Never underestimate the power of human stupidity
RAH
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
