Hi Rak4u,

Based on my understanding, you have a TabControl on a form. You don't want the user to switch among the tabpages by clicking the tab header. Instead, he can only do this by clicking the button on each tabpage. If I'm off base, please feel free to let me know.

When the user clicks onthe tab header of a TabControl, the TabControl receives WM_LBUTTONDOWN windows message and judge which tab header is clicked and then switch to that tab page. To prevent this, we can capture the WM_LBUTTONDOWN message and just discard it.

In addition, the user can also press Ctrl+Tab key to switch among the tabpages. To prevent this, we can override the OnKeyDown method and do nothing when Ctrl+Tab is pressed.

The following is a sample:
public class MyTabControl : TabControl
{
int WM_LBUTTONDOWN = 0x201;
protected override void WndProc(ref Message m)
{
if (m.Msg == WM_LBUTTONDOWN)
{

}
else
{
base.WndProc(ref m);
}

}

protected override void OnKeyDown(KeyEventArgs ke)
{
if (ke.Control && ke.KeyCode == Keys.Tab)
{
ke.Handled = true;
}
else
{
base.OnKeyDown(ke);
}
}
}

Use the derived TabControl instead of the standard TabControl on your form. The above code works fine on my side. Please try it in your application to see if there's any problem.

BTW, the IMessageFilterinterface allows an application to capture a message before it is dispatched to a control or form. A class that implements the IMessageFilter interface can be added to the application's message pump to filter out a message or perform other operations before the message is dispatched to a form or control. To add the message filter to an application's message pump, use the AddMessageFilter method in the Application class.

Obviously, it's not appropriate to add a message filter to the whole application in your scenario because what you need to do is to capture the message sent to just the TabControl.

Sincerely,
Linda Liu

First of all thanks Arjun for ur interest & help & also thanks hans. I read lot of ur post for help. I only entered in the programming job since last 2 month. I am working in Publighing house. they have no IT department Or IT staff. They want to develop their data entry program in vb.net & SQL server.
AS i mention i am a newbie no experience of any type. So i develop most of their model window application by taking help og internet & books but here i got in problem

My application is window application for dataentry. It has three tabpages First tab page is filter which is use to specify fitering condition to filter data from database & display that in datagrid present in second tab page browse. oN BROWSE TABPAGE i can present that data in excel format & also in crystal report.
then there is third tabpage ADDEDIT. On which ican edit the record or add new record. Tell me how u think about my approach to develop that application. Any suggesion help orimprovement in any aspect will welcom & must be appriciated

Now coming on current problem
As there is no selecting event in VS 2003 So what u think about usingIMessageFilter.PreFilterMessage
function & trap the click event od tabcontrol. I dont know how to use that function.

please tell me is that function is useful in this scenerio & if yes than please tell me any link to useIMessageFilter.PreFilterMessage function to capture click event of tabcontrol

againthanks all for ur support & help

bye

This is the same way what i had used but there is one error when i close application then it is not closed.

I used putting Tab=2 in closing event then application will close but by clicking two times to close because in first time in closing event the tab value change to 2 then it will close please solve this problem

thanks

Private Sub Form1_FormClosing(ByVal sender As System.Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles MyBase.FormClosing

e.Cancel = False

End Sub

Hi Rak4u,

Based on my understanding, you have a TabControl on a form. You don't want the user to switch among the tabpages by clicking the tab header. Instead, he can only do this by clicking the button on each tabpage. If I'm off base, please feel free to let me know.

When the user clicks onthe tab header of a TabControl, the TabControl receives WM_LBUTTONDOWN windows message and judge which tab header is clicked and then switch to that tab page. To prevent this, we can capture the WM_LBUTTONDOWN message and just discard it.

In addition, the user can also press Ctrl+Tab key to switch among the tabpages. To prevent this, we can override the OnKeyDown method and do nothing when Ctrl+Tab is pressed.

The following is a sample:
public class MyTabControl : TabControl
{
int WM_LBUTTONDOWN = 0x201;
protected override void WndProc(ref Message m)
{
if (m.Msg == WM_LBUTTONDOWN)
{

}
else
{
base.WndProc(ref m);
}

}

protected override void OnKeyDown(KeyEventArgs ke)
{
if (ke.Control && ke.KeyCode == Keys.Tab)
{
ke.Handled = true;
}
else
{
base.OnKeyDown(ke);
}
}
}

Use the derived TabControl instead of the standard TabControl on your form. The above code works fine on my side. Please try it in your application to see if there's any problem.

BTW, the IMessageFilterinterface allows an application to capture a message before it is dispatched to a control or form. A class that implements the IMessageFilter interface can be added to the application's message pump to filter out a message or perform other operations before the message is dispatched to a form or control. To add the message filter to an application's message pump, use the AddMessageFilter method in the Application class.

Obviously, it's not appropriate to add a message filter to the whole application in your scenario because what you need to do is to capture the message sent to just the TabControl.

Sincerely,
Linda Liu