I have a user control in my project and I want when I click on a button to add this user control to a form, but if the user control is already in the form I want to show it.
This the code I wrote so far:
Using GstAbonnement As New GestionAbonnement
GstAbonnement.Dock = DockStyle.Fill
Me.Controls.Add(GstAbonnement)
End Using
How can I test if the user control is already in the form or not ?
With your current code, that control will never be found in the form because the Using...End Using syntax with dispose of the control.
Try changing it to this:
Dim GstAbonnement As New GestionAbonnement
GstAbonnement.Name = "gestionAbonnement1"
GstAbonnement.Dock = DockStyle.Fill
Me.Controls.Add(GstAbonnement)
Notice I supplied a name for the control.
Now you can simply check the key if the control was in the collection or not:
If Me.Controls.ContainsKey("gestionAbonnement1") Then
Me.Controls("gestionAbonnement1").Visible = True
Me.Controls("gestionAbonnement1").BringToFront()
MessageBox.Show("Found!")
End If
You can use Form.Controls.Find to search for a specific control on a form. It also accepts a property to enable searching sub-controls (e.g. panels, groupboxes) which may contain the control.
You can use Form.Controls.Find as Su Sha said.
OR
You can loop through the Form.Controls to find the control with the specific name.
I'd prefer Form.Controls.Find function, its more safe and easier.
Related
I have a TextBox nested inside a TabControl.
Form->TabControl1->TabPage1->TabControl2->TabpPage2->GroupBox->TextBox
When the TabPage1, TabPage2 is selected, so the TextBox is visible to the user all the TextBoxEvents works OK, but when the user selects another TabPage it doesn't work.
I have a timer that send data periodically to know if an external device is present on a specific virtual COM port.
When the external device answer I put that data in that TextBox and set a global flag(boolean) to let the rest of the program that a device is present.
I'm processing the received data on a Private Sub and changing that TextBox with a Lambda expression like this
Me.Invoke(Sub()
Me.VersionFirmwareTxt.Text = RespX.Substring(5)
End Sub)
You can access the TextBox by name from anywhere whether it is visible or not, via casting (CType), and update its text value using the syntax:
'(from within the same Form, e.g., Form1)
CType(TabControl1.TabPages(1).Controls("VersionFirmwareTxt"), TextBox).Text = RespX.Substring(5)
'(from a different Form)
CType(Form1.TabControl1.TabPages(1).Controls("VersionFirmwareTxt"), TextBox).Text = RespX.Substring(5)
If you dynamically added the TextBox to the controls of the parent (TabPage), you will know exactly where the TextBox is located, since you would have already used, e.g.:
TabControl1.TabPages(1).Controls.Add(VersionFirmwareTxt)
Whereas if you manually added the TextBox to the TabPage, you also know the parent control.
I would really appreciate your advice on the following:
I'm working on Windows forms using VB.NET (even though the language is irrelevant to the question at hand).
I've got a main form and wish to call out another one, however depending on a given variable I need the text on some of the new form's elements to change as well as disable some of its controls.
There are two ways I see of doing it:
Send a parameter from the main form and have some logic on the second form to deal with everything on load.
Main Form:
dim newform as new frmcalculate(byval type as string)
New Form:
public sub getexplanation(byval type as string)
select type
case "Sum"
lblexplanation.text = "this is a sum"
case "Subtraction"
lblexplanation.text = "this is a subtraction"
End sub
Set exactly what I want on the main form before calling the new form.
i.e:
dim newform as new frmcalculate()
newform.lblexplanation.text = "This is a sum"
I hope I've managed to explain it correctly.
I'm still new at this especially getting the formats right on Stackoverflow.
In the first approach the code is best managed and organized for further editing. So each form has it own code.
It is not best practice to use second approach. (Editing a form designer from another one)
I have 4 checkboxes but we need to restrict selection to just a single one, meaning if you check the first, the other 3 will go unchecked. I know we could use ActiveX radio buttons but we'd prefer to avoid ActiveX if possible, plus with check boxes we have more control over the layout.
I've set the name of the checkbox appropriately to Check1:
And then I've put this very basic script into the Visual Basic section:
Private Sub Check1_Click()
Check1.Enabled = True
Check2.Enabled = False
Check3.Enabled = False
Check4.Enabled = False
End Sub
But unfortunately checking the first box doesn't uncheck the next 3.
Any ideas please? Thank you!
If these are Content Controls, as you indicate, then they do not have a CLICK event. Nor can they be identified by VBA by their Title property. The code you show us is for ActiveX controls, which you say you don't want to use...
Working with content control events is not as simple and intuitive as with ActiveX controls. Similar to form fields, Content Controls only have "editing" events that trigger on the user entering and exiting the content control. These events are available in the ThisDocument module, in the Document category.
The same ContentControlOnExit event triggers for ALL content controls in the document, so you need a Select Case or If conditional to query the ContentControl argument in order to know which content control was exited.
In order to address the other checkboxes you need to use the Document.SelectContentControlsByTitle (or ...ByTag) method which returns an array of all content controls with that title (or tag).
If you really want to emulate a "click" event then you need to insert a Custom XML Part in the document with nodes linked to the content controls. When the user changes the state of the control the ContentControlBeforeStoreUpdate event will trigger, letting you take action.
The property you need is Value, not Enabled.
The purpose of property Enabled is to prevent a control from being changed by user.
Additionaly, you need to prevent it from the events cascade. It means that when you change programatically the value of Check2, this will trigger Private Sub Check2_Click() and so on.
In order to make it work you should change your code like that:
Private Sub Check1_Click()
If Check1.Value Then
Check1.Value = True
Check2.Value = False
Check3.Value = False
Check4.Value = False
End If
End Sub
and similarly for the other check boxes.
For your purpose radio buttons will be better choice. Radio buttons have built-in functionality to uncheck currently selected button if other one is checked.
What I am trying to achieve is for a combo box (Combo_sf) selection to dictate the form in the subform control (sf_record) I have about 10 forms, their names are in the combo box data. I am new to VBA and am not sure if my approach is right:
Private Sub Combo_sf_AfterUpdate()
Dim strLoadTable As String
strLoadTable = "Form." & Me.Combo_sf.Value
MsgBox strLoadTable
Forms![frm_Mnu_Manage Configuration Settings]!sf_record.Form.SourceObject = strLoadTable
End Sub
I have placed this in the combobox's after update event but when I make my selection nothing happens in the form. Am I approaching this right or would another way work better?
Your approach should work. I put a combo box named cbxSubform on my main form and added one line of code to its AfterUpdate() event handler...
Private Sub cbxSubform_AfterUpdate()
Me.mySubform.SourceObject = Me.cbxSubform.Value
End Sub
...and changing the selection in the combo box switches the subforms immediately. Are you sure that the AfterUpdate() code for your combo box is actually firing? (You could add a MsgBox or a Debug.Print to check.)
It could be this line which is tripping you up:
strLoadTable = "Form." & Me.Combo_sf.Value
What is your form object called? If your form is called Form.myTableName it could be the . that is throwing it out, try setting it to a form without a dot in its name.
In this line, it seems the code attempts to change the SourceObject property of a Form object.
Forms![frm_Mnu_Manage Configuration Settings]!sf_record.Form.SourceObject = strLoadTable
However, SourceObject is a property of a subform control, not the form contained in that control. So if the subform control is named sf_record, do it this way.
Forms![frm_Mnu_Manage Configuration Settings]!sf_record.SourceObject = strLoadTable
Also, if the after update procedure runs from [frm_Mnu_Manage Configuration Settings], you can use Me to refer to the form.
Me!sf_record.SourceObject = strLoadTable
Finally, if Me.Combo_sf.Value is the name of a form, you don't need to prefix its name with "Form.". It worked either way in my test, but I would just leave off "Form.".
strLoadTable = Me.Combo_sf.Value
How to make a form always stay on top of another form.
Also both form's enabled property must be true
I don't wanna make use of topmost property.
Edit 1 :
Another similar question in C# says you can use Form.Owner Property to do the trick , how to make use of this property ?
Edit 2 : The Owner Property works fine untill I try to open it the second time.
This is the error message I get
I believe you need the frm.ShowDialog() instead of frm.Show()
frm is the other form you need to show over your current form and instead of using Show, this will make it as a dialog form over your current form (however you won't be able to select the parent form or the form behind it unless you close the frm form
EDIT
To enable edit on both forms
Form2 frm = new Form2();
frm.Owner = this;
frm.Show();
Hope this helps you out.