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Hello Everybody,
There are a lot of Source for Keyboard Hook. But i want to develop some new enhashment with keyboard Hook. Noew I am trying to capture Unicode characters.
I read a best article for only keyboard hook is
Global Windows Hooks[^]
But i want to convert it to Unicode.
So your help and suggestion is required.
Thanks
If you can think then I Can.
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I am kinda new with Visual Basic, and I am trying to make a system where I browse a video file, display it on a form, and process the video frame by frame to detect movements.
Ive read all over the place and most say use Windows SDK, ICImage something and etc..But I still cant understand any of them. Anyone mind sharing knowledge on how to do this? If anyone wouldnt mind giving me a step by step tutorial?
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Search the articles here on codeproject.
There are quite a few relating to motion detection. That should get you started.
If your new to it all, then video handling and motion detection is maybe a bit much to take on to begin with. just a thought.........
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You can try this, but VB.NET is no the first choice to do any kind of image processing. Why? Because VB.NET doesn't support pointers. Getting at image data fast enough to do this requires the use of pointers. You won't find any image processing or motion detection articles in VB.NET because of this.
This is better done in C# or C/C++.
Also, if your a beginner, this is not a good project to take on because of the complexity involved.
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Thank you for the pointers. Actually this is a class assignment, one which I really hope can do well, or at least have some functions in it. I do have some basics in C++ but its all blurry at times. At least anyone can show me how to use the library to access video files on a form?
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THIS is a class assignment? Very strange or a VB class.
I also have no idea what library you're talking about. The name you posted doesn't come up, but others of variants of the name you posted do.
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Zyprost wrote: Actually this is a class assignment,
What year are you in? And what languages did you cover yet?
I are Troll
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Yes it is a class assignment. We were to find an interesting topic,and make a proposal example,so i choose on movement detection, but I didnt knew that we actually have to make a system afterward lol.
We covered c++ last year, but only the basic functions, this year is java and some php. Some classmate said VB is like java so I wanted to try it. And on the library I said, think it was for c++, or was it java.idk, Many links I found said in order to display a video file on a form, I have to use them.
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Zyprost wrote: We were to find an interesting topic,and make a proposal example,so i choose on movement detection,
Definitely an interesting topic, you were right on that! It's also a complex topic, and I'm wondering why the teacher didn't mention that when he was reviewing the proposals.
Zyprost wrote: We covered c++ last year, but only the basic functions, this year is java and some php.
I'd love to see the curriculum of the school. Is there a website that lists the courses?
Zyprost wrote: And on the library I said, think it was for c++
This implies that you're allowed to use libraries written by others? If that's the case, start with this[^] CodeProject-article.
I are Troll
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Eddy Vluggen wrote:
Definitely an interesting topic, you were right on that! It's also a complex topic, and I'm wondering why the teacher didn't mention that when he was reviewing the proposals.
Ha ha maybe he didn't know that I was weak with programming. My scores were just average in class. So I need a big boost to get back what I lost.
And thanks for the link. Ive read them before and find it was interesting. I guess I will not use VB and use C++ instead. I will make sure to give credit to anyone involved.
Eddy Vluggen wrote: I'd love to see the curriculum of the school. Is there a website that lists the courses?
I don't even know if we have one at all. All I can focus on are my subjects, and finishing my assignments.
I will seek more help in the right section from now on I guess, but hopefully I wont need them. Thanks for helping. Rock on!!
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Even in c#, pointers are unsafe and unmanaged and must be declared as such. You need to jump through hoops to point to managed objects. You can use complex and often misused compilation tricks in either c# or vb.net to create a QuasiManagedPointer, but it not recommended, period. C++.net is the only way to go should you ever happen to really need to waste time in that direction.
Complexity is in the eye of the developer, especially with newbies who may look at this from a totally different perspective and use top pixel counts and thresolds to determine an image change (otherwise known as motion detection).
.net managed code uses the CLR in any language.
Stop spreading this nonsense.
Dwayne J. Baldwin
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Dwayne J. Baldwin wrote: Even in c#, pointers are unsafe and unmanaged and must be declared as such.
Hence the "unsafe" keyword...
Dwayne J. Baldwin wrote: You need to jump through hoops to point to managed objects. You can use complex and often misused compilation tricks in either c# or vb.net to create a QuasiManagedPointer
Not really, when you know what you're doing. Various cases in point...[^]
Dwayne J. Baldwin wrote: C++.net is the only way to go should you ever happen to really need to go in that direction.
I'm not about to talk anyone through that little maze of confusion. There are far more articles that are "newbie understandable" about C# pointers and image processing than there are on C++/CLI and VB.NET integration.
Dwayne J. Baldwin wrote: Stop spreading this nonsense
When everyone else does, and/or VB.NET gets better at faster image processing.
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Good find. Though it's not entirely pointerless as the author claims. It's still requiring unsafe code and the pinning pretty much just tells the GC to keep its mitts off the object and returns, of all things, a managed pointer to it. Different semantics doing the same thing...
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To get fram by frame, you can go for VLC media player plug in.. There you could have an option to snap video file which is playin'on it.. By using Timer set the interval and use snap make the video in to Image and then process whatever you want.. Still you had doubt, mail me at whitewinter_alone@yahoo.co.in
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you just need to use the openfilediag component and set a condition to test the file if it is the file extension you need or not. and display them is ok.
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Hi I use this code and want to add id and avtor to combobox but display the field "avtor", when I select some from combobox I want to get "id"
Private Sub avtori()
Dim selectdata As String
selectdata = "SELECT id, avtor FROM avtor"
Dim strConn As String
Dim reader As OleDbDataReader
'Низ за връзка с БД
strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & strAcessFilePath1 & ";Jet OLEDB:Database Password=;"
OleDbConnection2 = New OleDbConnection(strConn)
OleDbConnection2.Open() 'Отваряне на връзка с БД
OleDbCommand2 = New OleDbCommand(selectdata, OleDbConnection2)
reader = OleDbCommand2.ExecuteReader()
'Цикъл за извличане на всички автори и тяхното добавя към комбинирина списъчна кутия
Dim i As Integer
While reader.Read()
ComboBox1.Items.Add(reader("avtor"))
End While
reader.Close()
OleDbCommand2.Dispose()
OleDbConnection2.Close()
End Sub
modified on Saturday, February 5, 2011 2:15 PM
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Instead of going through a datareader and adding each item to the combobox, fill a datatable with the data, then bind the combobox to it using its DataSource property. Then set the combos DisplayMember (what the user sees in the list) and the ValueMember (what is returned by the combo) properties to the column names in the datatable.
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I have the following sub routine
Private Sub Exceptionquery()
Dim connection As System.Data.SqlClient.SqlConnection
Dim connectionString As String = "Initial Catalog=mdr;Data Source=xxxxx;uid=xxxxx;password=xxxxx"
Dim _sql As String = "SELECT [Exceptions].Employeenumber,[Exceptions].exceptiondate, [Exceptions].starttime, [exceptions].endtime, [Exceptions].code, datediff(minute, starttime, endtime) as duration INTO scratchpad3 " + _
"FROM [Exceptions]" + _
"where [Exceptions].exceptiondate between @payperiodstartdate and payperiodenddate" + _
"GROUP BY [Exceptions].Employeenumber, [Exceptions].Exceptiondate, [Exceptions].starttime, [exceptions].endtime," + _
"[Exceptions].code, [Exceptions].exceptiondate"
connection = New SqlConnection(connectionString)
connection.Open()
Dim _CMD As SqlCommand = New SqlCommand(_sql, connection)
_CMD.Parameters.AddWithValue("@payperiodstartdate", payperiodstartdate)
_CMD.Parameters.AddWithValue("@payperiodenddate", payperiodenddate)
Try
connection.Close()
Catch ex As Exception
connection.Close()
End Try
End Sub
Private Sub exceptionsButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles exceptionsButton.Click
Exceptionquery()
Dim connection As System.Data.SqlClient.SqlConnection
Dim adapter As System.Data.SqlClient.SqlDataAdapter = New System.Data.SqlClient.SqlDataAdapter
Dim connectionString As String = "Initial Catalog=mdr;Data Source=xxxxx;uid=xxxxx;password=xxxxx"
Dim ds As New DataSet
Dim _sql As String = "SELECT * from scratchpad3"
connection = New SqlConnection(connectionString)
connection.Open()
Dim _CMD As SqlCommand = New SqlCommand(_sql, connection)
_CMD.Parameters.AddWithValue("@payperiodstartdate", payperiodstartdate)
_CMD.Parameters.AddWithValue("@payperiodenddate", payperiodenddate)
adapter.SelectCommand = _CMD
Try
adapter.Fill(ds)
If ds Is Nothing OrElse ds.Tables.Count = 0 OrElse ds.Tables(0).Rows.Count = 0 Then
MessageBox.Show("There was no data for this time period. Press Ok to continue", "No Data")
connection.Close()
Exceptions.saveButton.Enabled = False
Exceptions.Hide()
Exceptions.Show()
Else
connection.Close()
Exceptions.Show()
End If
Catch ex As Exception
MessageBox.Show(ex.ToString)
connection.Close()
End Try
End Sub
and when I run my code, my subroutine is not being fired off. I know that because I would have a scratchpad3 in my sql database. I know that I'm probably missing something simple, but can anyone tell me what I may be missing?
Thank you
Doug
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At a quick glance you do not execute the command.
Also there's something peculiar about your try block. You catch an exception if it fail on closing the connection, then try to close again. Thus raising another exception?
Regards
David R
---------------------------------------------------------------
"Every program eventually becomes rococo, and then rubble." - Alan Perlis
The only valid measurement of code quality: WTFs/minute.
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David,
Thank you for pointing that out to me. I changed the code:
Private Sub Exceptionquery()
Dim connection As System.Data.SqlClient.SqlConnection
Dim connectionString As String = "Initial Catalog=mdr;Data Sourcexxxxx;uid=xxxxx;password=xxxxx"
Dim _sql As String = "SELECT [Exceptions].Employeenumber,[Exceptions].exceptiondate, [Exceptions].starttime, [exceptions].endtime, [Exceptions].code, datediff(minute, starttime, endtime) as duration INTO scratchpad3 " + _
"FROM [Exceptions]" + _
"where [Exceptions].exceptiondate between @payperiodstartdate and payperiodenddate" + _
"GROUP BY [Exceptions].Employeenumber, [Exceptions].Exceptiondate, [Exceptions].starttime, [exceptions].endtime," + _
"[Exceptions].code, [Exceptions].exceptiondate"
connection = New SqlConnection(connectionString)
connection.Open()
Dim _CMD As SqlCommand = New SqlCommand(_sql, connection)
_CMD.Parameters.AddWithValue("@payperiodstartdate", payperiodstartdate)
_CMD.Parameters.AddWithValue("@payperiodenddate", payperiodenddate)
connection.Close()
End Sub
and I thought by using this command in my next sub
Exceptionquery()
that I was calling that subroutine.
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Double-click on the "exceptionsButton" in the designer to make sure that it takes you to the specified procedure... VS may have mapped it differently.
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Chandra,
I double checked it and the mapping is correct.
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You are calling the routine but the routine does not execute the SqlCommand.
It just sets it up and provides values for the parameters.
You need and _CMD.ExecuteNonQuery.
BTW using _CMD as a variable name is a bit strange in VB - smacks of C++ with a mix of _ for class level variables and all upper case for constants. But that's a matter of taste.
Regards
David R
---------------------------------------------------------------
"Every program eventually becomes rococo, and then rubble." - Alan Perlis
The only valid measurement of code quality: WTFs/minute.
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PS Meant to say you could wrap the connection stuff in a try...finally...end try block with the close in the finally part. Note no catch - if an exception occurs it will be thrown but the close will still be done.
VB also has the using...end using construct to do this automatically so you don't need the close.
Regards
David R
---------------------------------------------------------------
"Every program eventually becomes rococo, and then rubble." - Alan Perlis
The only valid measurement of code quality: WTFs/minute.
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