Single checkbox to check multiple checkboxes in Visual Basic - vb.net

Question

Hi good people of stackoverflow, I have created a groupBox1 which contains 39 checkboxes which can be checked individually, and I have created a gropuBox2 which contains single check box called "Check All", What I want is when the "Check All" check box is checked all the 39 checkboxes will be selected and when the "Check All" is unchecked all 39 checkboxes will be unchecked also, Can someone please help? Thank you very much.

Answer 1

If all your controls are in the form ( not in groupbox/pannel) you can use the following code
Dim chk As CheckBox
If checkAll.Checked = True Then
For Each ctrl As Control In Me.Controls
If TypeOf ctrl Is CheckBox Then
chk = DirectCast(ctrl, CheckBox)
chk.Checked = True
End If
Next
End If
Updates as per edit and comment:
If you want to find controls inside Groupbox1 means you can do like the following
''' <summary>
''' sets CheckBox.Checked inside a container
''' </summary>
''' <param name="parentControl">the container</param>
''' <param name="chkState">ture or false</param>
''' <remarks>use: checkControls(GroupBox1, True)</remarks>
Public Sub checkControls(ByVal parentControl As Control, chkState As Boolean) '<----Pass the parent control where the checkBoxes belongs
Dim chk As CheckBox = Nothing
For Each ctrl As Control In parentControl.Controls '<-----Change from the above code
If TypeOf ctrl Is CheckBox Then
DirectCast(ctrl, CheckBox).Checked = chkState
End If
Next
End Sub
To check call the function as
checkControls(GroupBox1, True)'<----Since your checkboxes are inside the groupBox1
To uncheck call the function as
checkControls(GroupBox1, False)'<----Since your checkboxes are inside the groupBox1

Answer 2

Here's how I would do it. Filter the controls by type using Enumerable.OfType<T> then iterate the result using Array.ForEach<T>.
Private Sub CheckBoxAll_CheckedChanged(sender As Object, e As EventArgs) Handles CheckAll.CheckedChanged
Array.ForEach(Me.GroupBox1.Controls.OfType(Of CheckBox).ToArray(), Sub(box As CheckBox) box.Checked = Me.CheckAll.Checked)
End Sub

Answer 3

Assuming that there are only 40 checkboxes on the form then this will work
Dim ctrl As Control = Me.GetNextControl(Me, True)
Do Until ctrl Is Nothing
If TypeOf ctrl Is CheckBox Then
DirectCast(ctrl, CheckBox).Checked = True
End If
ctrl = Me.GetNextControl(ctrl, True)
Loop
If there are more than 40 checkboxes then take a look at Neethu Soman's solution.

Answer 4

I've tried the code below and works for me but Bjørn-Roger Kringsjå code works much better:
Private Sub cbxAll_CheckedChanged(sender As Object, e As System.EventArgs) Handles cbxAll.CheckedChanged
If cbxAll.Checked = True Then
cbx01.Checked = True
cbx02.Checked = True
' 3 .. 38
cbx39.Checked = True
Else
cbx01.Checked = False
cbx02.Checked = False
' 3 .. 38
cbx39.Checked = False
End If
End Sub