|
You need a global keyhook to do that, otherwise that code will only be triggered when your form as focus.
|
|
|
|
|
You can also set the form's KeyPreview property to True, then handle the form's KeyDown or KeyPress events to do the same thing.
|
|
|
|
|
I set KeyPreview = true in the form's properties dialog & then trap keydown
Private Sub frmInvoice_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles Me.KeyDown
If e.KeyData = Keys.Enter Then
'bla, bla, bla
e.Handled = True
End If
End Sub
|
|
|
|
|
Set the KeyPreview property of the form to True , that would solve your problem
-Regards
Bharat Jain
bharat.jain.nagpur@gmail.com
|
|
|
|
|
hey guy thanks for all your help 
J.Hardy
|
|
|
|
|
i got my control command to my external hardware. But the question now is i was unable to see the reply but i am sure there is a reply. Wat code should i insert to be able to see the reply?
|
|
|
|
|
why don't you try reading the data from the port?
What kind of question is this?
|
|
|
|
|
Please be clear as to what are you using, for now i am assuming that you you are using serial port component that comes with .net to revive any thing you must add an event handler for DataRecived event of serialPort component
You can the use serialPort1.ReadExisting() or serialPort.Read(), method to read from the serial port
Here is an link to a similar thread , related to receiving data from a serial port.
http://www.codeproject.com/script/Forums/View.aspx?fid=1649&msg=2897853[^]
Let me know if you need any more info
-Regards
Bharat Jain
bharat.jain.nagpur@gmail.com
|
|
|
|
|
Sorry for the unclear question. Ya wat i was trying to do was to retrieve data from my serial comm port. I am able to send to the comm port but not able to receive. I already seen the link u posted. I seen to be wat i am looking for but only ting is in C#. So i was wondering if u have the .net version?
|
|
|
|
|
this is the same code converted in vb
Private Sub SerialPort1_DataReceived(ByVal sender As
System.Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs)
Handles SerialPort1.DataReceived
If SerialPort1.BytesToRead > 0 Then
Dim byteToRead As Integer
byteToRead = SerialPort1.BytesToRead
Dim byteArray(byteToRead) As Byte
Dim lineData As String
SerialPort1.Read(byteArray, 0, byteToRead)
lineData = ConvertToString(byteArray)
End If
End Sub
Private Function ConvertToString(ByVal byteArray As Byte()) As String
Dim tempStringToReturn As String = ""
For Each bt As Byte In byteArray
tempStringToReturn = tempStringToReturn + Convert.ToChar(bt)
Next
Return tempStringToReturn
End Function
hope this helps ...........
-Regards
Bharat Jain
bharat.jain.nagpur@gmail.com
|
|
|
|
|
Please make note that i have not compiled the code , just did a manual conversion ..........
But i think it should work without any problems .
If you find any part which is not understandable please feel free to ask.
-Regards
Bharat Jain
bharat.jain.nagpur@gmail.com
|
|
|
|
|
So i should create an event as well right? By the way does the code u posted shows where the data will be display if the event is trigger? Cos i not sure if it is me that missed out anything, i cant find the displaying part.. thanks.
|
|
|
|
|
The current code does not contain the code to display any data 
The data is collected in the variable linedata , you can use message box (Messagebox.show(linedata)) to display this variable or else you can use any other method to display data (data is in the variable linedata).
Also i have used the event 'DataRecived' of serialport component.
Are you facing any problem with the event, just let me know the issue , may be i can suggest a solution for the same.
-Regards
Bharat Jain
bharat.jain.nagpur@gmail.com
|
|
|
|
|
hi.. Thanks for the info. Current already tried the code and the error "cross-thread" occurred. Beside ur code i oso added a line which is txtCommand.text = lineData, from copy the string of data received to be display on the textbox and tis line causes the error. Any way to solved tis error??
|
|
|
|
|
just try this line in form load
system.Windows.Forms.Control.CheckForIllegalCrossThreadCalls = False
this is not the best of the choice , but a quick solution , the error you are getting is because some of your control is been used in two different threads , i don't have any idea as to where any why you are using threads and hence , this is the only solution i can think of know
-Regards
Bharat Jain
bharat.jain.nagpur@gmail.com
|
|
|
|
|
Yup.. This is the solution that i am using now. But i encounter something which i find very weird. After i use the checkforillegalCrossthreadcalls = false, i put breakpoints at certain part of my code and it seens to work as i can see the reply from my hardware. But when i remove all my breakpoints the cross thread error did not occur but there isnt any reply from my hardware as well. Have been trying to find the reason behind it but till now there is still isnt any explanation.
|
|
|
|
|
This may happen because the output received from the serial port is been overridden by something going on in different thread ,Cross thread mainly occur when we try to access an object from two different treads ,by setting checkforillegalCrossthreadcalls = false we just suppress the error , but still the different thread continue to access the same object , when we apply break points , the other thread is suspended for that time and hence the application seems to work, i think you may have implemented threading in you project , you need to make sure that the all objects are used wisely , the same object must not be used in two different threads . I could have help you more if i have visibility to threading you have implemented.
-Regards
Bharat Jain
bharat.jain.nagpur@gmail.com
|
|
|
|
|
Thanks for the info i think the breakpoint issue should be related to the threading problem as well.. btw tis is my code.. i didnt use any thread but dun know y i encounter the problem..
Private Delegate Sub SerialPort1_DataReceivedDelegate(ByVal sender As System.Object)
Private Sub SerialPort1_DataReceived(ByVal sender As System.Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles port.DataReceived
If port.BytesToRead > 0 Then
CheckForIllegalCrossThreadCalls = False
Dim bytetoread As Integer
bytetoread = port.BytesToRead
Dim byteArray(bytetoread) As Byte
Dim lineData As String
port.Read(byteArray, 0, bytetoread)
lineData = ConvertToString(byteArray)
TxtCommand.Text = lineData
End If
End Sub
Private Function ConvertToString(ByVal byteArray As Byte()) As String
Dim tempStringToReturn As String = ""
For Each bt As Byte In byteArray
tempStringToReturn = tempStringToReturn + Convert.ToChar(bt)
Next
Return tempStringToReturn
End Function
modified on Wednesday, February 25, 2009 10:46 PM
|
|
|
|
|
No Clue !! , it does not seem that any threading is used in the code you pasted , i am really not able to think of any other cause of problem
-Regards
Bharat Jain
bharat.jain.nagpur@gmail.com
|
|
|
|
|
Sorry for bothering you with stupid sounding stuff from me newbie...
During my first tries with VB 2008 Express I'm creating an application which calls a command line tool for image processing (in loops). From their support I received the hint "With so many images to process, performance will be dramatically improved if you can use a scripting language like PerlMagick, RMagick, TclMagick, or a compiled language like C/C++."
I had thought that VB 2008 Express IS a compiled language. Is that wrong? Coming from VBA and VB Script I have some background with the VB syntax etc, that's why I chose to enhance that to VB 2008 rather than beginning with C for my simple (private) purposes.
Thanks for bringing some light to my darkness 
|
|
|
|
|
VB.Net compiles to MSIL (Microsoft Intermediate Language), and then you deploy that file (.exe) to your clients. Your clients must have the .NET Framework which includes the JIT (Just In Time) Compiler. The JIT then interprets your MSIL and executes the commands.
In short, it compiles, but not to native code such as C++/C. It compiles to MSIL. There are downsides to this, and upsides to this. Obviously, one of the bigger advantages is the fear of garbage collecting is gone when using a managed language, also the gigantic framework at your fingertips allowing you to develop applications at a great speed with (hopefully) little ease difficulty lol.
Hope that helps.
|
|
|
|
|
EliottA wrote: The JIT then interprets your MSIL and executes the commands.
No, it doesn't. The JIT compiles the MSIL code down to processor-specific native machine code.
So, yes, VB.NET is a compiled language, just like C# or C++, ...
|
|
|
|
|
Hey Dave,
after having written my other answer I just read yours and my live makes sense again  God bless you!
To be more serious: At least I humbly realized the big gap between a professional programmers (necessary?) approach and my limited skills - which are still good enough for enjoying it, and also for many programming tasks as long as I don't set myself too ambitious goals.
Sincerely
Michael
|
|
|
|
|
This reply is completely wrong.
The intermediate language is compiled into executable code at run-time, it is not interpreted and executed line by line. One of the main benefits of JIT compiling is that the compiler can optimize the resulting machine code to take advantage of the features of the CPU and operating system installed in the end-user's machine.
|
|
|
|
|
Little further clarification on what's been posted already for those not familiar with the topic.
MSIL is compiled to native (machine) code at runtime to take advantage of varying CPUs and architecture types; however the JIT compiler does not compile the entire assembly at once - it is done at a method by method level. It is possible to pre-compile using NGEN.
When a method is called, that method then gets compiled to native code (once per the lifetime of the assembly). If there are methods that are never called during the operation of the assembly, then they never get converted to native code. This is done to increase performance during startup and runtime of the assembly to avoid a massive hit during initial startup.
Any suggestions, ideas, or 'constructive criticism' are always welcome.
"There's no such thing as a stupid question, only stupid people." - Mr. Garrison
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
