Passing DataContext to Button Event Handler

[Paolo]

How do I pass a DataContext to a button_click event handler. I have the
following:

public partial class frmMain : Form
{
public frmMain()
{
InitializeComponent();

string cnStr =
@"Data Source=.\SQLEXPRESS;AttachDbFilename=L:\Workspace\SQL
Databases\Training.mdf;"
+ "Integrated Security=True;Connect Timeout=30;User
Instance=True";

DBDataContext db = new DBDataContext(cnStr); // typed DataContext
}

private void btnList_Click(object sender, EventArgs e)
{
var act_types =
from a in db.Activities // error: name 'db' does not exist
in
// the current
context
from t in db.Types // ditto
where a.Activity_Type == t.Type_Id

orderby a.Activity_Date
select new
{
a.Activity_Date,
t.Type_Desc,
a.Activity_Distance,
a.Activity_Duration,
a.Activity_Route
};

dgvList.DataSource = act_types; // show query results in
DataGridView

}

Thanks

 

[Stefan Hoffmann]

hi Paolo,

How do I pass a DataContext to a button_click event handler.

Use a global variable:

public partial class frmMain : Form
{
DBDataContext _DataContext = null;

public frmMain()
{
InitializeComponent();
string cnStr = @"Data Source=.\...";>
_DataContext = new DBDataContext(cnStr); // typed DataContext
}

private void btnList_Click(object sender, EventArgs e)
{
var act_types = from a in _DataContext.Activities ...
}
}


mfG
--> stefan <--

 

[Paolo]

Stefan: yes, visibility. This hit me while lying in bed this morning. Thx.