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I think the gyst of the question was "Why isn't an int allocated on the heap and GCed by default".
Non-static class fields are stored on the heap within the memory areas that are allocated to objects. They go bye-bye if the objects containing them are garbage-collected. I believe static fields are stored on the heap as well, but in regions that generally won't go bye-bye until an application terminates (I think there are ways of explicitly unloading DLL's which would nuke any static fields they hold, but I don't know the details).
As noted before, local variables are stored on the stack, and will go bye-bye when, or soon after, they go out of scope.
Note that class variables hold references to objects; the class variables themselves are value types (which may be stored on the stack or within the space allocated for particular objects), but they will cause the system to maintain objects as standalone allocations.
Thus, if there is a local variable of type "System.Text.Stringbuilder", the local variable will exist on the stack only as long as it is within scope. If the variable is not Nothing, there will be an object of type System.Text.Stringbuilder to which that variable points. When the variable goes out of scope, the four or eight bytes used by the reference itself will go away regardless of whether other references exist to the same StringBuilder.
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Static types and fields are stored in what is called a Loader Heap. Loader heaps are separate from the normal GC heap, and are managed in a different way. They are not garbage collected (since they are static and live for the duration of the app, there is no need), and space for statics is preallocated when the AppDomain is loaded. If a Static member contains a reference to another, non-static object...the object that is referenced is actually stored on the GC heap. Static fields and methods are keept on loader heaps because they are considered part of the type system (wich is the primary purpose for loader heaps...to store type metadata, vtables, etc.) Its actually an interesting distinction between static and instance types.
Given that this thread has diverged from simple answers, perhapse the following link will be helpful to everyone. It explains the CLR, GC, and type system in detail:
http://msdn.microsoft.com/en-us/magazine/cc163791.aspx
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I want to link a application to another website via relative path and it's giving me hell, any help?
Ferron
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ferronrsmith wrote: it's giving me hell
Because you can't. Relative paths work within the application, not outside it.
only two letters away from being an asset
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actually got it fixed, thanks man
Ferron
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Care to share the fix?
ɹǝʌo ɹoʇıuoɯ ɹnoʎ dılɟ sıɥʇ pɐǝɹ ʇ,uɐɔ noʎ ɟı
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I have implemented my own MyDataView so that I can process the raw data before it appears in a data grid.
MyDataView implements IBindingList.
MyDataView has a collection of MyDataRow objects. MyDataRow implements ICustomTypeDescriptor.
MyDataView also has a collection of MyDataColumn objects, which it shares with the MyDataRow objects.
MyDataRow exposes the collection of MyDataColumn through the ICustomTypeDescriptor interface.
When assigning the DataSource property of the grid to an instance of MyDataView, it displays all the columns and rows correctly, as long as there is at least one row of data to display.
However, when the MyDataView has no rows, the grid shows a single column called "Column" instead of the actual columns in the collection. This makes sense to me since the columns are exposed through the row, and there are no rows.
Somehow, I need the grid to see MyDataView's column definitions even if there are no rows in the view.
I tried modifying MyDataView to also implement ICustomTypeDescriptor, but it did not seem to have any effect.
How do I get a grid to see MyDataView's column definitions even if there are no rows in the view?
(I'm using the DevExpress.XtraGrid.GridControl from Developer Express.)
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public string connection = "Provider=SQLOLEDB; Data Source=D:king.txt;Catalog=STU_ATTENDANCE;User ID=sa;Password=sa; Network Library=dbmssocn";
SqlConnection con1 = new SqlConnection(connection);
in my text file king i gave this text "veeserv3" <--(this is my data source name)
is it right...
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Please Don't Cross Post 
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I don't know if you can treat an arbitrary text as a database. A CSV-text, no problems. It kinda depends on the format of your textfile. Can you show us a small excerpt (5 lines), including escape-characters?
Anyway, if you want to verify that your connection-string works and can connect to the datastore, invoke the function described below;
internal bool TryConnectToSqlInstance(string connectionString)
{
using (SqlConnection con = new SqlConnection(connectionString))
try
{
con.Open();
}
catch (SqlException ex)
{
MessageBox.Show(String.Format("{0}\n\nConnection string: '{1}'", Message, connectionString}
Application.ProductName,
MessageBoxButtons.OK,
MessageBoxIcon.Error);
}
finally
{
while (con.State == ConnectionState.Connecting)
Application.DoEvents();
if (con.State == ConnectionState.Open)
MessageBox.Show("Connection Succeeded!",
Application.ProductName,
MessageBoxButtons.OK,
MessageBoxIcon.Information);
}
}
You might also be interested in this[^] link, where you can find various connectionstrings for almost every database.
I are troll 
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No, you cannot refer to the contents of the text file as the data source. Use config file or read the text from the textfile, for example using File.ReadAllLines[^] amd then place the contents to your connection string.
Something like:
string[] datasource = File.ReadAllLines("D:\\king.txt");
string connection = "Provider=SQLOLEDB; Data Source="
+ datasource[0]
+ ";Catalog=STU_ATTENDANCE;User ID=sa;Password=sa; Network Library=dbmssocn";
modified on Thursday, January 22, 2009 12:15 PM
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nice gentle man u got my problem...
when i include those lines i get this error....
"File does Not exist in the current context"
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File class is under System.IO namespace, so you can refer to it like System.IO.File.ReadAllLines(... or add using System.IO directive to your file.
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i got this error
Could not find file 'D:\king.txt'.
but i have word file in my d:
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As the message says, the file cannot be opened. Re-chek the path and the name and if another application is having that file open, close the other application first.
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the file did not open any where in my project...
i gave like this...
string[] datasource = File.ReadAllLines("D:\\king.txt");
Could not find file 'D:\king.txt'.
if i give like this....
string[] datasource = File.ReadAllLines("D:\king.txt");
Error 1 Unrecognized escape sequence //occurs
i gave like this...
string[] datasource = File.ReadAllLines("D:king.txt");
Could not find file 'D:\king.txt'.
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The problem isn't in your code, but the code cannot open the file from the operating system. Check (for example using windows explorer) that:
- the file is on drive D and in the root directory
- the file is named king.txt
- you have privileges to open the file
- the file isn't open in any program, for example in Microsoft Word etc.
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file read successfully but..
reading in this manner ::ࡱ\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0>\0\0\t\0\0\0ࡱ\0\0\0\0\0\0\0\0\0\0\0\0\0
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Are you sure it's a plain text file and not for example in Word format? Open it using notepad. It should answer that question. File-class reads the text as plain text. If the file contains some other format, File class is unable to "translate" it to text.
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i typed "veeserv3" in that word doc... it is not empty...
"Format of the initialization string does not conform to specification starting at index 0."
this error also occured..
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VERY VERY THANKS GENTLE MAN...
I GOT THE RESULT...
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hi. im working on a project that requires inserting, deleting values in the database.
i used the datagridview and edit on the values directly on the grid. it worked but when i try to refresh it, the new values are just appended. example, there are only 2rows in the table. when i click the refresh button, 2rows are appended making it 4 rows of the same value. please help.. need it badly..
another thing is that when i change the name for the data table, directly updating on the datagrid is impossible.
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Sounds like there are some problems in your bindings from the datatable to the datagridview. But without seeing your code, it's hard to say more.
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thanx for the reply..
Dim listquery1 As String
If conn.State = ConnectionState.Open Then conn.Close()
Try
conn.Open()
If cboSubj.SelectedItem.ToString = "ICSM310" And cboSec.SelectedItem.ToString = "Z14" Then
listquery1 = "Select *from sampleList;"
Dim mycmd As New MySqlCommand(listquery1, conn)
mycmd.ExecuteNonQuery()
adptr.SelectCommand = mycmd
adptr.Fill(dtable)
DataGridView1.DataSource = dtable
DataGridView1.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.AllCells
Else
MsgBox("No list ")
End If
Catch ex As Exception
MsgBox(ex.Message)
End Try
conn.Close()
this is the first instance for loading the values in the datagrid...
for the "refresh" command
Dim listquery As String
If conn.State = ConnectionState.Open Then conn.Close()
Try
conn.Open()
Try
listquery = "Select *from sampleList;"
Dim mycmd As New MySqlCommand(listquery, conn)
mycmd.ExecuteNonQuery()
adptr.SelectCommand = mycmd
adptr.Fill(dtable)
statusView.DataSource = dtable
statusView.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.AllCells
Catch myerror As MySqlException
MsgBox("There was an error reading from the database: " & myerror.Message)
End Try
Catch myerror As MySqlException
MessageBox.Show("Error connecting to the database: " & myerror.Message)
Finally
If conn.State <> ConnectionState.Closed Then conn.Close()
End Try
End Sub
note that statusView is datagridview
for the mysql adapter and datatable, i declare it at the very beginning of the code..
for me to use the command builder command...
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Few observations:
jetgrageda wrote: mycmd.ExecuteNonQuery()
That should be unnecessary.
Before fill, you could call dtable.Clear()
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