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Hello All ,
I was readinf the lock concept and find that there is problem with lock(this) or lock(public type).
what is the problem doing like that ?
Please explain me with an example
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A good starting point for research is the documentation[^]. I think you would be surprised at the information available in MSDN.
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Nah. MSDN documentation is like holiday brochures without pictures, nothing interesting there. 
Luc Pattyn [Forum Guidelines] [My Articles]
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Actually, the particular article I referenced while sparse does indicate the common problems and a common solution in the remarks section. Although, most MSDN is total crap.
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I check the documentation . I did not get that what was the problem .
any way we are making lock on that object . So what matters if that is private or public?
Please help me out
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you could as well ask why private and protected members exist at all. Why not make everything public?
it is a matter of encapsulation, separation of concern, improving reliability, etc.
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No That i not mean at all . what i got confused is anyhow i am locking that object . So untill i done with my work no body can tamper it with .
So even if i declare private or public i am holding a lock on that . So how that acces specifier will affect that .
Sorry to trouble u .. bUt a good example will clear my doubt .. my brain is not able to leav this doubt unanswered.
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when your locker object is public I can lock it without your code being aware of it; so all your code would break right away. Don't make public what doesn't have to be public, that is one of the OO principles.
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Yet with Reflection I can see your privates. 
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You'd better think twice before applying reflection on me... 
Luc Pattyn [Forum Guidelines] [My Articles]
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The problem with Lock(this) and Lock(type) is that these objects are public, so an external code could lock on them. So if your class is named YourClass, I can make a code like this:
YourClass obj = new YourClass();
lock(obj){ ... }
And that would probably deadlock your internal code. Same problem for a public type. Since it is commom to lock an object that you want to protect, it's not too dificult for a code like this to happen.
The best approach is to create an object just for locking on it, instead of locking the class object. Make this locking object "static" and you get the same effect of locking a type.
Regards,
Leonardo Muzzi
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Hi All,
I am having problems adding a new row to a datagridview control in my form. I have a simple form
with datagridview. When the user types in an item number in the first columen by event
the system will populate the datagridview with the relevant data from the database.
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I presume you want to fill in other columns in the new row based on the item number in the first column.
You can use the validated event of the cell:
- You get an DataGridViewCellEventArgs object with rowindex and columnindex
if Columnindex == 0
{
// Collect the data from the database
DataTable dt1 = datatablefunction(relevantsql);
//Write the data in the appropiate cells
this.DataGridView.rows[e.RowIndex].Cells["NameOfCell"].value = dt1.rows[0]["ColumnName"].toString();
}
This is all aircode, but I hope this helps.
Rob
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I have treeview which is in panel. As it grows scroll bar of the treeview appear. I want capture the scroll bar value and set the value to another treeview in another panel. But I could see that there is no scroll event for treeview. How can do that?
Thanks in Advance
Regards
Surya 
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Unfortunately I can't provide any sample code because I can't get access to Visual Studio, but in terms of a scroll event, I'd create a class which inherits from TreeView and overrides the WndProc method. If m.Msg == WM_MOUSEWHEEL, then you've got a scroll message; you just have to interpret m.WParam and m.LParam properties in a fashion. When the derived class provides a Scroll event, use that instead of the TreeView control
Between the idea
And the reality
Between the motion
And the act
Falls the Shadow
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thanks for the help. I will try that.
Best Regards
Surya
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Hi All,
I'm having some problems finding the correct Forms event from which to fire my code. I want to run a sequence of code automatically once a form is displayed on the screen.
Form_load isn't correct as my code finished before the form is displayed.
Form_Shown doesn't seem to trigger consistently.
Form_Activated triggers multiple times
Form_Validated doesn't seem to trigger consistently.
What event should i use?
I basically want the code to fire as if the form was displayed on the screen and I hit a "Start Button".
Thanks in advance.
Daniel.
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Shown should fire exactly once, the first time the form has become visible.
MSDN: "Occurs whenever the form is first displayed."
Luc Pattyn [Forum Guidelines] [My Articles]
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Recently i get a project about a clinic software and i have a little problem with the previous database information. so i thought that you are the best one that could answer me,
let me describe a little...
the previous software has a feature that allow to the doctor to write the patients information by hand writing with a electrical pen, it so like paint brush software and it save this information in the database like bellow,
AORtHQTwD4AEAh4CSBEHSBFEgID8BwRIEEU1B0gRRP8BRQgFSBFE/wEEAwE4ABgiIDIJAPT/AgHpIjpFMwkA+J8CAVogOkU4CAD+AwAAAIB/AA8OEvkjjT/PI40/EQAAgD8eKLQBhvAdR4DpyGhwAAAAAAAAAAAAAAIAZ4yvRgAAnp8AACGhwAAAAAAKIgqE+ry+sL1Y4RhHXsCF8iV5DHKLKIJsTICFqxzDyy14ueEKIgmH5jDmMYFA51D5XSIqh+Ow47GwWG2Sug26
so i don't know what exactly it is, but i guess it could be a Multimedia Format Like jpeg or anything else like that, do you know what it could be, and how can i solve this problem!
thank you very much!
With best Regards!
--
Maysam Gamini
Bachelor Of Information Technology
Faculty Of Engineering, Isfahan University
E-mail address: Mit.gamini@gmail.com
E-mail address: Ir.webbiz@gmail.com
Phone: +9821-20105677
Cell No: +98912-3778746
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chances are it is some kind of binary data (a byte array) made readable through Convert.ToBase64String;
so call the reverse function, and look at it;
maybe save it in a file, give it different extensions, and try opening it.
There isn't much data in your example.
Luc Pattyn [Forum Guidelines] [My Articles]
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Show formatted code inside PRE tags, and give clear symptoms when describing a problem.
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Seems to me that this is a binary field written in the String Base 64 format. You can try using Convert.FromBase64String to generate a binary stream, then you can try writing this stream as an image to the browser.
Regards,
Leonardo Muzzi
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Thank You In Advance, I'll try it and send another reply again, and report the result!
about the example that i post, it's quite a content of the database field.
there is some another here!
1.
AORtHQTwD4AEAh4CSBEHSBFEgID8BwRIEEU1B0gRRP8BRQgFSBFE/wEEAwE4ABgiIDIJAPT/AgHpIjpFMwkA+J8CAVogOkU4CAD+AwAAAIB/AA8OEvkjjT/PI40/EQAAgD8eKLQBhvAdR4DpyGhwAAAAAAAAAAAAAAIAZ4yvRgAAnp8AACGhwAAAAAAKIgqE+ry+sL1Y4RhHXsCF8iV5DHKLKIJsTICFqxzDyy14ueEKIgmH5jDmMYFA51D5XSIqh+Ow47GwWG2Sug26
2.
AL5cHQTeD7IDAhsCSBEHSBFEgID8BwRIEEU1CkgRVw0AAABQ/wEEAwE4ABgiIDIJAPT/AgHpIjpFMwkA+J8CAVogOkU4CAD+AwAAAIB/AA8OEvkjjT/PI40/EQAAgD8eJ5kBhfcye5jAAAAAijAAAAAAAAAAAAABdfBBGBIlAAEGAtg4IzHHYApKHoT7Gb7GficXVrxWaMOKtqzx4WHVFSk6RzwAhfIVeQrw2HpowMODnwc9sEFVGAuxkGMqoughqviAhONqlDfjinGcKk
3.
ANKqAR0EtA+IBAIOAkgRBUgRRP8BBEgQRTUEAwE4ABgiIDIJAPT/AgHpIjpFMwkA+J8CAVogOkU4CAD+AwAAAIB/AA8OEvkjjT/PI40/EQAAgD8eL6sCgoAAAAAAAAAAAePIAABmgAAAAAAAAePIAAAAAASkoAAAAAACKAAAABmgAAAACkYfhPsVvsZ8zMlKSmONp2rivSsZ3VjdwOWAhfCKeEzxjGSUTTRQyz4Gu/C130zoJLJqsIx0YIP0tMefm5qZtCJImS98/D6oCi
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Well, it's definitely a String Base 64, 'cause I was able to build a byte array from it with this code:
string strData = @"AORtHQTwD4AEAh4CSBEHSBFEgID8BwRIEEU1B0gRRP8BRQgFSBFE/wEEAwE4ABgiIDIJAPT/AgHpIjpFMwkA+J8CAVogOkU4CAD+AwAAAIB/AA8OEvkjjT/PI40/EQAAgD8eKLQBhvAdR4DpyGhwAAAAAAAAAAAAAAIAZ4yvRgAAnp8AACGhwAAAAAAKIgqE+ry+sL1Y4RhHXsCF8iV5DHKLKIJsTICFqxzDyy14ueEKIgmH5jDmMYFA51D5XSIqh+Ow47GwWG2Sug26";
byte[] data = Convert.FromBase64String(strData);
The problem is, I wasn't able to write it as an image in a .net page, using the Response.BinaryWrite method. So, maybe it's not a commom image binary data. You can test this byte array saving as a file and try some extensions.
Regards,
Leonardo Muzzi
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Hai Friends,
I want to create a .net application to capture and monitor the video of a webcam of particular system in a LAN Network using C#.
help me with you ideas.
Thanks,
Vasanth.A
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