Making combobox visible when it is disabled - vb.net

I am disabling combobox in VB.net.
But in disable mode it not visible properly.
I tried changing both BackColor and ForeColor but it is not working.
Code :
cmbbox.BackColor = Color.FromName("Window")
or
cmbbox.ForeColor = Color.FromName("Window")
Please help
Dear Adam:
I am making my component enable false.But I want to make it viewable.You can reffer the link.This is what exacly I want but in VB.Net : A combobox that looks decent when it is disabled

To achieve disabling combobox without fading it, first change the dropdown style of the combobox to DropDownList, Then tweak with the events to achieve the goal.
Here is a piece of code by which you can achieve the same:
Public Class Form1
Dim selectindex As Integer
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
ComboBox1.Items.Add("1")
ComboBox1.Items.Add("2")
ComboBox1.Items.Add("3")
ComboBox1.Items.Add("4")
selectindex = 3
ComboBox1.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList
ComboBox1.SelectedIndex = selectindex
End Sub
Private Sub ComboBox1_SelectionChangeCommitted(ByVal sender As Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectionChangeCommitted
ComboBox1.SelectedIndex = selectindex
End Sub
End Class
Create anew form Form1 and add a combobox to the form, then add the above code to get a readonly combobox.

Have a look at this thread which has a solution for a readonly combobox and the code is all VB.NET.
A version of their code is as follows. You'll need to but it inside a class of your own which inherits System.Windows.Forms.ComboBox
Private _ReadOnly As Boolean = False
Public Property [ReadOnly]() As Boolean
Get
Return _ReadOnly
End Get
Set(ByVal Value As Boolean)
_ReadOnly = Value
End Set
End Property
Public Overrides Function PreProcessMessage(ByRef msg As Message) As Boolean
'Prevent keyboard entry if control is ReadOnly
If _ReadOnly = True Then
'Check if its a keydown message
If msg.Msg = &H100 Then
'Get the key that was pressed
Dim key As Int32 = msg.WParam.ToInt32
'Ignore navigation keys
If key = Keys.Tab Or key = Keys.Left Or key = Keys.Right Then
'Do nothing
Else
Return True
End If
End If
End If
'Call base method so delegates receive event
Return MyBase.PreProcessMessage(msg)
End Function
Protected Overrides Sub WndProc(ByRef m As Message)
'Prevent list displaying if ReadOnly
If _ReadOnly = True Then
If m.Msg = &H201 OrElse m.Msg = &H203 Then
Return
End If
End If
'Call base method so delegates receive event
MyBase.WndProc(m)
End Sub

I've been looking for the same not long ago and ended up doing the following. You may not like it, but i'll share it in case. I am using TableLayoutPanel to arrange my controls on the form and then i am swapping the positions of the desired controls.
For example I've created the following Items:
Form1 Design
TableLayoutPanel1 (two columns, three rows)
TextBox1 Read-only = True, BackColor = White
ComboBox1 Visible = False, DropDownStyle = DropDownList, FlatStyle = Popup
Button1 (named it to Change)
Button2 (named it to Done) -> Visible = False
Runtime - Screenshots
Here is my code:
Public Class Form1
Private Sub SwapControls(tlp As TableLayoutPanel, ctr1 As Control, ctr2 As Control)
Dim ctl1pos As TableLayoutPanelCellPosition = tlp.GetPositionFromControl(ctr1)
ctr1.Visible = False
tlp.SetCellPosition(ctr1, tlp.GetPositionFromControl(ctr2))
ctr2.Visible = True
tlp.SetCellPosition(ctr2, ctl1pos)
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
SwapControls(TableLayoutPanel1, TextBox1, ComboBox1)
SwapControls(TableLayoutPanel1, Button1, Button2)
Label1.Select()
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
SwapControls(TableLayoutPanel1, ComboBox1, TextBox1)
SwapControls(TableLayoutPanel1, Button2, Button1)
Label1.Select()
End Sub
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Label1.Select()
ComboBox1.SelectedIndex = 0
TextBox1.Text = ComboBox1.SelectedItem
End Sub
Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
TextBox1.Text = ComboBox1.SelectedItem
End Sub
End Class

Related

cmbComboBox.SelectionStart always returns zero irrespective of cursor location

For some reason the "SelectionStart" property behaves differently from TextBox to ComboBox.
Create a TextBox and a ComboBox. Make sure DropDownStyle = DropDown (NOT DropDownList!)
Add these Leave events (same result if you use LostFocus event):
Private Sub TextBox1_Leave(sender As Object, e As EventArgs) Handles TextBox1.Leave
Debug.Print("Textbox: " & TextBox1.SelectionStart)
End Sub
Private Sub ComboBox1_Leave(sender As Object, e As EventArgs) Handles ComboBox1.Leave
Debug.Print("ComboBox: " & ComboBox1.SelectionStart)
End Sub
Now type text into each control and change focus from control to control, with the selection cursor in different places in the string.
I get this:
Textbox: 6
ComboBox: 0
Textbox: 8
ComboBox: 0
Textbox: 5
ComboBox: 0
Textbox: 4
ComboBox: 0
... and so on
When the textbox loses focus, it returns the correct SelectionStart.
When the combobox loses focus, it always returns zero.
Is there a reason, solution or reasonable workaround? I cannot seem to intercept this without creating a new variable for each combo control, and storing the SelectionStart on every click and keypress event (assuming the user might click the mouse, use arrow keys or type characters).
I just did some testing and it appears that the selection is reset between the Leave and LostFocus events as well as between the Enter and GotFocus events. I tried remembering the values on the first of each pair and restoring it on the second and it worked as desired:
Private comboBox1SelectionStart As Integer
Private comboBox1SelectionLength As Integer
Private Sub ComboBox1_Enter(sender As Object, e As EventArgs) Handles ComboBox1.Enter
comboBox1SelectionStart = ComboBox1.SelectionStart
comboBox1SelectionLength = ComboBox1.SelectionLength
End Sub
Private Sub ComboBox1_Leave(sender As Object, e As EventArgs) Handles ComboBox1.Leave
comboBox1SelectionStart = ComboBox1.SelectionStart
comboBox1SelectionLength = ComboBox1.SelectionLength
End Sub
Private Sub ComboBox1_GotFocus(sender As Object, e As EventArgs) Handles ComboBox1.GotFocus
ComboBox1.SelectionStart = comboBox1SelectionStart
ComboBox1.SelectionLength = comboBox1SelectionLength
End Sub
Private Sub ComboBox1_LostFocus(sender As Object, e As EventArgs) Handles ComboBox1.LostFocus
ComboBox1.SelectionStart = comboBox1SelectionStart
ComboBox1.SelectionLength = comboBox1SelectionLength
End Sub
You don't want to have to do that every time for every CokmboBox so you can build it into a custom control and then use that in place of the standard control:
Public Class ComboBoxEx
Inherits ComboBox
Private selectionStartTemp As Integer
Private selectionLengthTemp As Integer
Protected Overrides Sub OnEnter(e As EventArgs)
MyBase.OnEnter(e)
'Remember the current selection.
selectionStartTemp = SelectionStart
selectionLengthTemp = SelectionLength
End Sub
Protected Overrides Sub OnGotFocus(e As EventArgs)
'Restore the selection.
SelectionStart = selectionStartTemp
SelectionLength = selectionLengthTemp
MyBase.OnGotFocus(e)
End Sub
Protected Overrides Sub OnLeave(e As EventArgs)
MyBase.OnLeave(e)
'Remember the current selection.
selectionStartTemp = SelectionStart
selectionLengthTemp = SelectionLength
End Sub
Protected Overrides Sub OnLostFocus(e As EventArgs)
'Restore the selection.
SelectionStart = selectionStartTemp
SelectionLength = selectionLengthTemp
MyBase.OnLostFocus(e)
End Sub
End Class
A side-effect of this is that you will see the text selected even when the control doesn't have focus. The ComboBox has no HideSelection property like the TextBox does. If you don't like this then I'd imagine that you could find a way to make it behave like the TextBox does but that's a different question so I won't go into it here.
I think I've got it, using your idea but just setting the value in a different location.
Dim ComboSelectionStart As Integer
Private Sub cmbComboBox_KeyUp(sender As Object, e As KeyEventArgs) Handles cmbComboBox.KeyUp
'Store selection on any key press
ComboSelectionStart = cmbComboBox.SelectionStart
End Sub
Private Sub cmbComboBox_MouseClick(sender As Object, e As MouseEventArgs) Handles cmbComboBox.MouseClick
'Store selection on any mouse click
ComboSelectionStart = cmbComboBox.SelectionStart
End Sub
Private Sub cmbComboBox_Leave(sender As Object, e As EventArgs) Handles cmbComboBox.Leave
'Returns correct value here because it was not altered by LostFocus event
Debug.Print(ComboSelectionStart .ToString)
End Sub
When you modify the OnLeave() sub in the class provided by #jmcilhinney it actually works nicely.
Protected Overrides Sub OnLeave(e As EventArgs)
'Remember the current selection.
selectionStartTemp = SelectionStart
selectionLengthTemp = SelectionLength
MyBase.OnLeave(e) 'this has to go last because it modifies the SelectionStart...
End Sub

Menu Item Custom Control Events

I am trying to create a menu list item that contains both a textbox and a label as a single item. In the code below I have made the necessary custom control class inherited from ToolStripControlHost and this looks and behaves as expected when created in the form menu.
The problem I am having is that the control's events are not firing the handler routine. In the example below, what I would expect to happen is that when the user types into the text box a message should show (other events have the same problem).
Thank you.
Control Classes:
Public Class ToolStripTextBoxWithLabel
Inherits ToolStripControlHost
Public Sub New(Optional ByVal lblText As String = "label")
MyBase.New(New ControlPanel(lblText))
End Sub
Public ReadOnly Property ControlPanelControl() As ControlPanel
Get
Return CType(Me.Control, ControlPanel)
End Get
End Property
End Class
Public Class ControlPanel
Inherits Panel
Friend WithEvents txt As New TextBox
Friend WithEvents lbl As New Label
Public Sub New(ByVal lblText As String)
Me.Height = 20
lbl.Anchor = AnchorStyles.Left Or AnchorStyles.Top Or AnchorStyles.Bottom
lbl.Text = lblText
lbl.TextAlign = ContentAlignment.BottomLeft
lbl.AutoSize = True
lbl.Height = Me.Height
lbl.Location = New Point(0, 3)
lbl.Parent = Me
txt.Anchor = AnchorStyles.Left Or AnchorStyles.Right Or AnchorStyles.Top
txt.Location = New Point(lbl.Right + 3, 0)
txt.Width = Me.Width - txt.Left
txt.Parent = Me
End Sub
End Class
Form Implementation:
Public Class Form1
Friend tb_SearchBox As ToolStripTextBoxWithLabel
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
tb_SearchBox = New ToolStripTextBoxWithLabel("Search:") With {.Name = "tb_SearchBox"}
AddHandler tb_SearchBox.TextChanged, AddressOf tb_SearchBox_TextChanged
Item1ToolStripMenuItem.DropDownItems.Add(tb_SearchBox)
End Sub
Private Sub tb_SearchBox_TextChanged(sender As Object, e As EventArgs)
MsgBox("Success")
End Sub
End Class
Using the TextChanged event of your ToolStripTextBoxWithLabel in this instance is inappropriate because that event should only be raised when the Text property of that object changes, which is not happening here. You need to do what Plutonix suggested but you should also do it with your own custom event rather than with the TextChanged event of the host, e.g.
Public Event TextBoxTextChanged As EventHandler
Protected Overridable Sub OnTextBoxTextChanged(e As EventArgs)
RaiseEvent TextBoxTextChanged(Me, e)
End Sub
Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
OnTextBoxTextChanged(EventArgs.Empty)
End Sub
Rather than deriving your ControlPanel class from Panel and creating the child controls in code, I would suggest that you create a user control and add the children in the designer. You would then use my answer below in two steps, i.e. the user control would handle the TextChanged event of the TextBox and then raise an event of its own that would, in turn, be handled by the ToolStripTextBoxWithLabel that would its own event.
Thanks to jmcilhinney and Plutonix I have put together the solution. For completeness and future community reference the full solution is below.
User Control:
Public Class CustomTextBox
Public Event TextBoxTextChanged As EventHandler
Protected Overridable Sub OnTextBoxTextChanged(e As EventArgs)
RaiseEvent TextBoxTextChanged(Me, e)
End Sub
Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
OnTextBoxTextChanged(EventArgs.Empty)
End Sub
Public Sub New (lblText as string)
InitializeComponent()
Caption = lblText
End Sub
Public Property Caption() As String
Get
Return Label1.Text
End Get
Set(ByVal value As String)
Label1.Text = value
End Set
End Property
Public Overrides Property Text() As String
Get
Return TextBox1.Text
End Get
Set(ByVal value As String)
TextBox1.Text = value
End Set
End Property
Public Class
Implementation:
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
Dim SearchBox As New CustomTextBox("Search")
Dim host As ToolStripControlHost = new ToolStripControlHost(windowNewMenu)
AddHandler SearchBox.TextBoxTextChanged, AddressOf SearchBox_TextChanged
ToolStripMenuItem1.DropDownItems.Add(host)
End Sub
Private Sub SearchBox_TextChanged(sender As Object, e As EventArgs)
MsgBox(sender.Text)
End Sub

Custom Textbox Zoom - Return text to active datagridview cell?

I have 2 Datagridview controls in same form. Each Datagrid has some columns where user will write long texts, so I designed form with RichTextBox that opens when user double-clicks these columns to enlarge text-entry. Code works, but I want to use same form for both Datagrids, so I should somehow return text to active datagridview cell. Here is my code (for Datagridview1):
TextZoomForm:
Public Class TextZoomForm
Public OpenedForm1 As New Form1
Private Sub RichTextBox1_DoubleClick(sender As Object, e As EventArgs) Handles RichTextBox1.DoubleClick
OpenedForm1.DataGridView1.CurrentCell.Value = RichTextBox1.Text
OpenedForm1.Label24.Focus()
Me.Close()
End Sub
Private Sub TextZoom_Load(sender As Object, e As EventArgs) Handles Me.Load
RichTextBox1.Text = OpenedForm1.DataGridView1.CurrentCell.Value
End Sub
End Class
DataGridView1_CellMouseDoubleClick in Form1:
Private Sub DataGridView1_CellMouseDoubleClick(sender As Object, e As DataGridViewCellMouseEventArgs) Handles DataGridView1.CellMouseDoubleClick
If e.ColumnIndex = 1 Then
Dim cp = Cursor.Position
cp.Y += CInt(Cursor.Size.Height * (-0.5))
cp.X += CInt(Cursor.Size.Width * 0.8)
Dim f As New TextZoomForm()
f.OpenedForm1 = Me
f.Show()
f.Location = New Point(cp)
End If
End Sub
Any ideas on how to return text to active datagridview cell?
Change your zoomed form so that it doesn't know where its data comes from. Instead the control using it will pass the data.
Public Class TextZoomForm
Public Property ZoomedText As String
Get
Return RichTextBox1.Text
End Get
Set(value As String)
RichTextBox1.Text = value
End Set
End Property
Private Sub RichTextBox1_DoubleClick(sender As Object, e As EventArgs) Handles RichTextBox1.DoubleClick
Me.Close()
End Sub
End Class
To call the form change your code to the following:
Private Sub DataGridView1_CellMouseDoubleClick(sender As Object, e As DataGridViewCellMouseEventArgs) Handles DataGridView1.CellMouseDoubleClick
...
Dim f As New TextZoomForm()
f.ZoomedText = DataGridView1.CurrentCell.Value
f.ShowDialog()
'Great breakpoint location.
DataGridView1.CurrentCell.Value = f.ZoomedText
Label24.Focus()
....
End Sub
Using ShowDialog prevents the user from changing the current cell part way through your call.
If you need it modeless then you should:
store the cell that the user has selected
handle the FormClosing event.
Test the DialogResult to make sure the user pressed ok
write the data back to the stored cell.

Automatic SelectAll on all textboxes and numericUpDown controls on gotfocus

I have such code to make all text in textbox selected on got_focus:
Private Sub myText_GotFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles myText.GotFocus
myText.SelectAll()
End Sub
Is here a way in VB.NET to get that all TextBoxes and NumericUpDown controls selects his text on _GotFocus or _Enter without to explicitly set such behavior for every single control and no matter how this control gets a focus (keyboard, mouse or programmatic)?
Yes, there is and very simple.
Private Sub TextBox2_GotFocus(sender As Object, e As System.EventArgs) Handles TextBox2.GotFocus
TextBox2.Select(0, TextBox2.Text.Length)
End Sub
Public Class MyTextBox
Inherits System.Windows.Forms.TextBox
Private _focused As Boolean
Protected Overrides Sub OnEnter(e As EventArgs)
MyBase.OnEnter(e)
If MouseButtons = MouseButtons.None Then
SelectAll()
_focused = True
End If
End Sub
Protected Overrides Sub OnLeave(e As EventArgs)
MyBase.OnLeave(e)
_focused = False
End Sub
Protected Overrides Sub OnMouseUp(mevent As MouseEventArgs)
MyBase.OnMouseUp(mevent)
If Not _focused Then
If SelectionLength = 0 Then
SelectAll()
End If
_focused = True
End If
End Sub
End Class

Highlight in Listboxes without permitting user selection

Is there a way to highlight an item in a VB.Net listbox without
allowing the user to change selection?
When I set the selection Mode to "NONE" I canĀ“t select an item in the code.
Same when I disable the listbox.
Setting the list box' Enabled property to False works fine:
Public Class Form1
Public Sub New()
InitializeComponent()
ListBox1.Items.AddRange(New String() {"one", "two", "three"})
ListBox1.Enabled = False
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
ListBox1.SelectedIndex = 1
End Sub
End Class