CODEWITHSUNDEEP
c#vb.net
Skitzafreak
Skitzafreak

Reputation: 1917

Detect if CTRL key is pressed when Left Click on DataGridView Header

I have created a class in VB.Net that is a child of DataGridView. I am trying to create a method that detects when there has been a left click on one of the column headers, and then checks to see if the CTRL key is pressed when the click event fires. This is the code I have so far:

Private Sub Self_ColumnHeaderLeftClick(sender As Object, e As DataGridViewCellMouseEventArgs) Handles Me.ColumnHeaderMouseClick
    If e.Button <> MouseButtons.Left Then Return
    If (Control.ModifierKeys = (Keys.LControlKey Or Keys.RControlKey) Then
        MessageBox.Show(Columns(e.ColumnIndex).Name)
    EndIf
End Sub

It's suppose to be simple right now, and just pop up a message box when holding either CTRL key and left clicking on one of the headers. However nothing is happened. I know the event method is firing, because if I move the MessageBox line into an Else block under the If statement, I get the message boxes appearing. What am I doing wrong?

Upvotes: 2

Views: 1623

Answers (3)

dbasnett
dbasnett

Reputation: 11773

You can probably adapt this to your needs

Private Sub SomeDGV_ColumnHeaderMouseClick(sender As Object,
                                              e As DataGridViewCellMouseEventArgs) Handles dgvPending.ColumnHeaderMouseClick

    If e.Button = Windows.Forms.MouseButtons.Left Then

        If My.Computer.Keyboard.CtrlKeyDown Then
            'control key down
        Else
            '
        End If

    End If
End Sub

Upvotes: 1

Olivier Jacot-Descombes
Olivier Jacot-Descombes

Reputation: 112712

The condition should be

Control.ModifierKeys = Keys.LControlKey Or Control.ModifierKeys = Keys.RControlKey

because Keys.LControlKey Or Keys.RControlKey combines the two Keys values to form a new one containing both, LControlKey and RControlKey. This would mean that you have to press both control keys at the same time.

See: Use Enumerated Values with Bit Flags to Handle Multiple Options

Okay, it looks like you are getting a Keys.Control, no matter which control key you are pressing. So simply test

if Control.ModifierKeys = Keys.Control Then

Upvotes: 0

Flydog57
Flydog57

Reputation: 7111

Control.ModifierKeys is of type System.Windows.Forms.Keys which is an enumerate type annotated with the FlagsAttribute. You probably want to test a condition something like:

(Control.ModifierKeys AND Keys.LControlKey = Keys.LControlKey) OR (Control.ModifierKeys AND Keys.RControlKey = Keys.RControlKey)

The first half of that expression says "are all the bits of Keys.LControlKey set in Control.ModifierKeys. The second half does the same thing for Keys.RControlKey.

Upvotes: 2

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