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I have a mixed VB/C# solution. I have a class in VB which inherits from a C# base class. The derived VB class has an attribute applied to it which the constructor of the C# base class reads.
However, when I build my code (I think incrementally) and run I get "Multiple custom attributes of the same type found." when I execute...
DataDatabase lDatabaseAttr = (DataDatabase)Attribute.GetCustomAttribute(GetType(), typeof(DataDatabase), false);
There is only one instance of this attribute, AFAIK.
If I do a full rebuild of the solution the problem goes away, only to return when I next do a build incrementally.
Suffice to say I have climbed the wall several times and now look to you guys for expert guidance on where I have gone wrong.
Thanks in advance.
Nursey
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Hi All,
I would like to check if the machine is idle. If yes, then the program will trigger something.
Thank you, Wilfred;)
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I am considering the infrastructure for the licensing of applications.
I do not want to use hardware devices such as dongles as I would like users to be able to download the software.
I am interested in using a Web Service to validate registered/paid users.
I have so far detailed the following procedure and appreciate any feedback.
All comments are welcome especially ideas on improving or circumventing similar techniques.
The procedure is as follows:
A user supplies registration details when downloading software from a server. The details are stored in a database and a registration code generated.
The user is sent a copy of the details along with a registration code to the email address supplied during the registration procedure.
The user enters the registration details including registration code into the application.
The client application gathers system specific information which could include MAC Address, Hard Disk Size/Serial Number, Windows Serial Number. This information is used known as a client profile.
The client application generates a new Public Key to be used by the server when responding to an activation request. This key is then appended to the data and encrypted using the Servers Public Key.
The application attempts to connect to the server to request an activation code and passes the encrypted data.
The server decrypts the data using its Private Key and validates the details against a database.
The validation routine checks the following conditions:
1) Has the software already been activated?
2) Has the client profile changed?
3) Are the relevant subscriptions up to date?
The server encrypts a reply using the Clients Public Key and responds to the activation request.
If a positive reply is received from the server, a licence is generated on the client PC by the client application and is encoded with the activation date/time and license number.
The client application periodically checks the validity of the licence by querying the server.
As I said, any comments apreciated.
Regards
Wayne Phipps
____________
Time is the greatest teacher... unfortunately, it kills all of its students
LearnVisualStudio.Net
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i want to use process bar on form with timer but i can not do this plz help me with coding.
thank you.
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Process Bar? What's that?
I take it you mean a Progress Bar?
The ProgressBar is easy enough to use. Set the Minimum and Maximum properties to what ever you want, defaults are 0 and 100. Then set the Step property to an increment value, say 1. That will give to 100 steps through the progress bar. Now, when you want to increment the progress bar, just call the bar's PerformStep method.
If say, you were copying 5 files and wanted a progress bar to show how many file have been copied, you would set Minimum to 0, Maximum to 5, and Step to 1. When the first file is successfully copied, you call PerformStep(), when the next file is done, PerformStep(), ...
RageInTheMachine9532
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Hi,
I am trying to select a row in a DataGrid by simply clicking on the row (any column in the row) which will in turn open a new form with various controls which are binded to the original record which was selected in the DataGrid.
I have the following code which selects the whole row when clicked
Private Sub DataGridComplaints_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles DataGridComplaints.MouseUp<br />
Dim pt = New Point(e.X, e.Y)<br />
Dim hti As DataGrid.HitTestInfo = DataGridComplaints.HitTest(pt)<br />
If hti.Type = DataGrid.HitTestType.Cell Then<br />
DataGridComplaints.CurrentCell = New DataGridCell(hti.Row, hti.Column)<br />
DataGridComplaints.Select(hti.Row)<br />
End If<br />
End Sub
How do I use a column in the selected row to pass information into a variable which can then be used on the next form?
Many thanks for any help you can give me.
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try this:
var=DataGridComplaints.item(hti.Row,x) 'where x is the number of the column that you are trying to get data from
Cosmin
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You could use this logic also to select a row, which has been clicked ( I am not sure which has better performance or whether this logic has a drawback) :
If DataGrid1.CurrentRowIndex > -1 then
DataGrid1.Select(DataGrid1.CurrentRowIndex)
End if
I think to get column value of selected row, you should get it from the underlying DataSet (or DataTable) using the CurrentRowIndex of the DataGrid
For Eg, if your DataSet ds has a table which is shown in the DataGrid, and you want to get value of column with index 3 of currently selected row,
col3Value = ds.Tables(0).Rows(DataGrid1.CurrentRowIndex).Item(3)
But this logic will fail if you have used the RowFilter to filter rows from the DataSet's default view. This is because the row index of DataGrid and that in the DataSet wont be same.
To overcome that you could use this logic to get the DataRow in the DataSet corresponding to the row selected in the DataGrid:
Private Function GetDataRow() As DataRow
Dim dr() As DataRow = ds.Tables(0).Select(ds.Tables(0).DefaultView.RowFilter)
Return dr(DataGrid1.CurrentRowIndex)
End Function
From the returned DataRow, you can take the required value :
col3Value = dr.Item(3)
Hope it helped.
----------------------------------------------------------------------------
"I think there is a world market for maybe 5 computers"
Thomas Watson, chairman of IBM, 1943
"There is no reason anyone would want a computer in their home"
Ken Olson, chairman & founder of Digital equipment, 1977
"This 'telephone' has too many shortcomings to be seriously considered as a means of communication. The device is ingerently of no value to us."
Western Union internal memo, 1876
"640 K ought to be enough for anybody."
Bill Gates, 1981
"Computers in the future may
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HOW I CAN CONVERT COLOR IMAGE TO GRAY SCALE IMAGE
THANK..
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sense... make... doesnt... it?
plz try again.
------------------------
Jordan.
III
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You might want to check out the ImageAttributes class.
RageInTheMachine9532
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I don't know yet if anyone has this problem!
Let's say that I have a database that will store all the information about an order and items and customers… each have a table that is related to the other…
The Problem is that the design of the database is not friendly to the user, this mean if I want to put a Data Grid and bind it to the OrderDetails table, then the user will see the ItemId and not the ItemName (Of cores, because the database is well normalized !).
So, to work around this problem a made another User-Friendly table and each time the user ask to see an order detail, the code will translate the data from the original Unfriendly table to the friendly table…
This worked fine, but what I would do if the user decides to make changes to the order?
Again I have to copy the data from the User-Friendly table to the database (unfriendly table!). This is a complex operation and very hard to do, especially if there is a large number of a table I work with in my original database…
I have the same problem if I want to use crystal report!
Because crystal report will not deal with a large number of related tables, I am forced to make a new table that is a copy of my report design, and each time the user ask to print a report, the data will be transformed to this table, so crystal report can deal with it fine and print the report !!
The question is: if there is a problem with my design concept or I should built a new object that inherit from the dataset object and can join tables together and can send the data back to the original database??? And how to do this??
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I don't know yet if anyone has this problem!
Let's say that I have a database that will store all the information about an order and items and customers… each have a table that is related to the other…
The Problem is that the design of the database is not friendly to the user, this mean if I want to put a Data Grid and bind it to the OrderDetails table, then the user will see the ItemId and not the ItemName (Of cores, because the database is will normalized !).
So, to work around this problem a made another User-Friendly table and each time the user ask to see an order detail, the code will translate the data from the original Unfriendly table to the friendly table…
This worked fine, but what I would do if the user decides to make changes to the order?
Again I have to copy the data from the User-Friendly table to the database (unfriendly table!). This is a complex operation and very hard to do, especially if there is a large number of a table I work with in my original database…
I have the same problem if I want to use crystal report!
Because crystal report will not deal with a large number of related tables, I am forced to make a new table that is a copy of my report design, and each time the user ask to print a report, the data will be transformed to this table, so crystal report can deal with it fine and print the report !!
The question is: if there is a problem with my design concept or I should built a new object that inherit from the dataset object and can join tables together and can send the data back to the original database??? And how to do this??
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I'm not very familiar with crystal reports, but as far as the grid goes, I never use a data-bound anything. You should populate the grid from an SQL statement, then if you're allowing them to edit stuff right in the grid ( which I also don't do), make sure that once they leave that record you use an insert or update statement depending on which fields were edited or added.
If it's broken, I probably did it
bdiamond
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I agree with bdiamond on this.
Data Binding a UI control directly to the database IMO violates the proper layering of a solution. The layers are presentation (that communicates with the user), business (it performs the business logic, validation, enforces the rules of the system and so on) and data (this communicates with the database). The layers should only talk to the adjacent layer. The larger the project the more important this is. For a smaller project then the layers can get fuzzy as it is not so important.
If you must use data-binding then having the binding done on the result of a Stored procedure would be better because the stored procedure can join the "friendly" table with the other table.
From the sound of what you are doing I'm not convinced that the addition of your friendly table is aiding the normalisation. The 5th-Normal-Form IIRC is where you create lookup tables that are used to expand enumeration so should increase the normalisation of your database, but from your description you seem to be denormalising the database - expecially if changes in one table require a change in the other.
"You can have everything in life you want if you will just help enough other people get what they want." --Zig Ziglar
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I wholeheartedly agree with the comments from the people above.
Your database seems to be normalised database and if you cannot bind it directly to the DataGrid it is best to bind it to several other controls (e.g. using textboxes, comboboxes, etc.) instead of creating the 'friendly' table and bind it to one DataGrid.
For crystal report, it is always best to create your own queries and use the queries to build the report, instead of linking the tables in crystal report itself. Trust me, you'll be thankful that you use queries instead of tables when your database changes.
The answer is: The database sounds normalised and seems to be fine. Your approach is not recommendable and you should read more about binding data to the form and get some examples before continuing.
Edbert P.
Sydney, Australia.
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thanks for all pepole that answer my question (and because my english is not good i can't find the words that express my felling...)
ok, it's fine, i build the query that will create my friendly table and i generated the dataset that will hold the results and bind it to a datagrid (it is not possible to bind an order form to textboxes or anything else!! the datagrid is the excellent choice), but there is 2 problem i think:
the first problem is what will happen if the user decide to make a change to the order ?
the second problem is that i use the Ado.Net (and dataset) because i can use the data in a 'disconnected world' ! this mean that i need to work with the data for a long time (2 day maybe) befor i send finaly the data to the databse. so i can't use the T_Sql queries ! (because i need a connection to the datasource that is not availalble all the time !). so i always connect to the datasource, copy a portion of data to a local XML file, save it to disk to work with it, so i always work with DataView objects to make my queries ! my datasource is most the time is a local XML file that a dataset object will read when the application start !! so what is the solution !!
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Has anyone else suffered a memory leak in their VB.NET programs?
I have a few classes that are created when a form is created. The whole thing is quite complex and wasn't written by me. I would expect any class I create to be destroyed when the form is closed, but they all seem to sit around in memory. The garbage collector just seems to shuffle about all the time and not free the memory.
Even when I do nothing in the application, the GC reports varying values for the GetTotalMemory() method. My problem is that I can't tell what is referencing the memory that can't be freed. A restart of the application is the only way to clear the memory at the moment.
Any advice? I'm getting desparate! 
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Google for '.NET Memory Profiler' or 'Allocation Profiler'. You'll find a bunch of them , some trial version, some shareware. I've used the Allocation Profiler from GotDotNet before with pretty good results, plus, you can get the source for it!
RageInTheMachine9532
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I downloaded the trial of SciTech .NET Memory Profiler 2.0 (http://www.scitech.se/memprofiler/Default.htm). This tool helped me find the memory leak.
FWIW: When I create an event handler for a multi-line text box, the form sits in memory after being closed. I removed the handlers and the form is removed! I've never seen anything like it. I have NO CODE in the handler, just this:
Private Sub TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtTextbox1.TextChanged
End Sub
And if I remove it, my 1K+ form will remove itself from memory. If the handler is in there, no number of GC.collect statements will free the damned thing.
Garbage I say GARBAGE !!!
Don't worry, nobody lives forever.
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Hi, I want to implement a folder browser for VSS using VB6 (just like explorer in windows ). how do i go abt it? if any1 has sample code, plz share.
Antony
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I don't know if that works in VB6, but it works in vb.net:
Add a reference to the SHELL32.DLL file (in WINDOWS\SYSTEM32). Then try the following code:
Dim folder As Shell32.Folder
Dim dlg As New Shell32.Shell()
folder = dlg.BrowseForFolder(Me.Handle.ToInt32, "Select a folder", 4)
Cosmin
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I am trying to make a shareware application in vb .net that does some very simple CRM stuff. The problem I have is that, as i understand it, you need the .NET framework on every computer the application will run on.
Is there a way to compile the app. into a stand alone .exe that doesnt require the framework or is there something seriously flawed with my reasoning?? (Going back to VB6 sucks)
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You MUST install the .NET Framework on every machine that will run the any .NET compiled app. You CAN NOT compile the Framework into your app. You, also, cannot include the .NET Framework in an installer package created by Visual Studio. This is because one of the first thing the resulting .MSI does is check to see if the Framework is installed. If not, the .MSI quits with the message 'This setup requires the .NET Framework. Please install the .NET Framework and run this setup again.'
You can make an installer, called a 'boot strap', for your app installation that checks for and installs the .NET Framework, then installs your app from it's .MSI package. See this[^] article and code sample on CP. Also, Microsoft has this[^] article on MSDN covering the same bootstrap principle.
RageInTheMachine9532
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The reason there is a .NET framework
1. That all apps wil run on all pc's with the .net framework 
2. You don't have to download huge files to get a .net application becouse all that is in the 20 MB .net framework.
3. Apps will work with all windows platforms with 1 code.
So you can't compile the framework in you app.
you can let the installer install .net framework read the help in VS.NET
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