Panel sent-to-back don't work

[Chong]

I want to design panels at design time; however, when I right click on the panel and click sent-to-back the panel behind this panel doesn't appear. It seems nothing happen with the sent-to-back or bring-to-front option.

Many thanks in advance for the help.

ljCharlie

[Pirate]

I'm using VS.NET 2003 , and it's working well .

[Chong]

It works now. The problem I had was because I didn't change the underlying form to IsMdiContainer=true before I created the panels.

ljCharlie

[Pirate]

It shouldn't make much difference though . . good it's working now .

[Chong]

That's what I thought too but what I have to do is deleted the already created panels and recreate them.

By the way, since it seems you know a lot about vb.net, how do I call a class within another class? Well, here's what I'm trying to do. I am trying to organize my codes a bit since I don't want too many codes just within one form.vb, so I decided that I'm going to add another class so I can put some of my codes into that class. The problem is I don't know how to execute another class once the main class has been executed. Another question I have is, is this the best way to do? What other alternatives besides adding another class?

Many thanks for your help.

ljCharlie

[Pirate]

I'm not sure If I know a lot about VB.NET as you said but I'll try to help .

Well , as I understand it , you want to move your code in the form to a class file . Then call your functions from the form . right ?

If so , then it's better to mark your functions asPublic Shared so that you can call it from anywhere without instantiating it . Clear ?

[Chong]

Let's said I have a class name Computers and in this class I have the Paint function to load my data from a database mdb file into a datagrid. How do I call this in my main form? Another question, the event function Paint will have to be declared as Public shared, correct? Because I think by default it is created as Private Sub.

Again, thanks for the help.

ljCharlie

[Pirate]

This demo should answer your questions .It's commented also .

For the second question , the default in functions and sub is Public I guess . And you have to make it public so that you can call it within your form .

[Chong]

Many thanks for your help. I will take a look at the demo.

ljCharlie

[Chong]

Pirate, I have another question. I believed your demo was created under VB.NET 2003 that's why I wasn't able to open it. However, I was able to open the individual .vb files. Still, I have one more question. I have a datagride in, let's say frmMain, but how do I access this datagrid's properties in another class, let's say clsComputer? When I'm creating a public function to load the data from a datbase mdb file into frmMain's datagrid1, how do I do that? Here's what I have tried access in the clsComputer class:

Public Class clsComputer
Private Shared mdbPath As String = Application.StartupPath & "\Computers.mdb"
Dim clsMain As frmMain
Dim CompDG As DataGrid = clsMain.dgComputer
Public Function ComputerDG()
Dim strConn As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & "Data Source=" & mdbPath
Dim strSQL As String = "SELECT * FROM Computer"
Dim compDataAdapter As New OleDbDataAdapter(strSQL, strConn)
Dim compDataSet As New DataSet()
Dim ts As New DataGridTableStyle()

compDataSet.Clear()
compDataAdapter.Fill(compDataSet, "CompDevices")
CompDG.DataSource = compDataSet.Tables!CompDevices

'GET CURRENCY MANAGER
Dim cm As CurrencyManager

cm = CType(clsMain.BindingContext(compDataSet.Tables!CompDevices), CurrencyManager)

'CREATE DATAGRIDSTYLES AND MODIFY

ts = New DataGridTableStyle(cm)
ts.GridColumnStyles(0).HeaderText = "Serial#"
ts.GridColumnStyles(0).Alignment = HorizontalAlignment.Center
ts.GridColumnStyles(0).ReadOnly() = True
ts.GridColumnStyles(1).Alignment = HorizontalAlignment.Center
ts.GridColumnStyles(1).ReadOnly() = True
ts.GridColumnStyles(2).Alignment = HorizontalAlignment.Center
ts.GridColumnStyles(2).ReadOnly() = True
ts.GridColumnStyles(3).HeaderText = "Date Purchased"
ts.GridColumnStyles(3).Alignment = HorizontalAlignment.Center
ts.GridColumnStyles(3).ReadOnly() = True
ts.GridColumnStyles(3).Width() = 100
CompDG.TableStyles.Add(ts)
End Function
End Class

But I received an error:

An unhandled exception of type “System.NullReferenceException’ occurred in Devices.exe

Additional information: Object reference not set to an instance of an object.

If I declared
Dim clsMain As frmMain as Dim clsMain As New frmMain then I don't receive any error, the problem now is that the data does not load from the database mdb file into the datagrid in the frmMain form.

ljCharlie

[Pirate]

If I were you I wouldn't do it the way you have done . Tell you why ? First , you are nothing making use of the function again . Second , You're not making any sense of OOP here . Here is the ideal solution :

Public Class clsComputer
 
Public Shared Sub ComputerDG(ByVal MYfrm As Form , ByVal MYDataGrid As DataGrid)
 
Dim mdbPath As String = Application.StartupPath & "\Computers.mdb"
Dim strConn As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & "Data Source=" & mdbPath
Dim strSQL As String = "SELECT * FROM Computer"
Dim compDataAdapter As New OleDbDataAdapter(strSQL, strConn)
Dim compDataSet As New DataSet()
Dim ts As New DataGridTableStyle()
 
compDataSet.Clear()
compDataAdapter.Fill(compDataSet, "CompDevices")
MYDataGrid.DataSource = compDataSet.Tables!CompDevices
 
'GET CURRENCY MANAGER
Dim cm As CurrencyManager
 
cm = CType(MYfrm.BindingContext(compDataSet.Tables!CompDevices), CurrencyManager)
 
'CREATE DATAGRIDSTYLES AND MODIFY
 
ts = New DataGridTableStyle(cm)
ts.GridColumnStyles(0).HeaderText = "Serial#"
ts.GridColumnStyles(0).Alignment = HorizontalAlignment.Center
ts.GridColumnStyles(0).ReadOnly() = True
ts.GridColumnStyles(1).Alignment = HorizontalAlignment.Center
ts.GridColumnStyles(1).ReadOnly() = True
ts.GridColumnStyles(2).Alignment = HorizontalAlignment.Center
ts.GridColumnStyles(2).ReadOnly() = True
ts.GridColumnStyles(3).HeaderText = "Date Purchased"
ts.GridColumnStyles(3).Alignment = HorizontalAlignment.Center
ts.GridColumnStyles(3).ReadOnly() = True
ts.GridColumnStyles(3).Width() = 100
CompDG.TableStyles.Add(ts)
End Function
End Class

Then call it like this from your form :

ComputerDG(frmMain , yourdatagrid on the form)

not tested though...

[Chong]

Perfect! It works! I should've thought of passing the form and the datagrid through the function. I was too concentratedon the class and not the function it self.

Many thanks for your help again.

ljCharlie

[Pirate]

Glad to be helpful ...