say I have a Button1 subroutine
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim buttonText As String = Button1.Text
someOtherRoutine(buttonText)
End Sub
I have a lot of such buttons in my main form. They all do the same thing like this. get the text and pass to some other routine. If i have 20 buttons, then i will have 20 such subroutines. Is there a better (or standard way) to do this without creating that many subroutines?
thanks
You can use this one subroutine to handle all of the buttons:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) _
Handles Button1.Click, _
Handles Button2.Click, _
...
Handles Button20.Click
Dim myButton As Button = sender
Dim buttonText As String = myButton.Text
...
End Sub
You can use AddHandler to add the same event handler for every button or you can use a comma separated list in the Handles clause.
Sub EventHandler() Handles Obj.Ev_Event, Obj2.Ev_Event
' Handle the event.
MsgBox("EventHandler caught event.")
EndSub
Related
A noob query I have, is there any way to use a single command to open different forms on different button click events. I have 24 buttons in one form and will use these buttons to open 24 different forms.
So instead of doing it for 24 times as:
Private Sub BtnCh1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnCh1.Click
FormCh1.Show()
End Sub
Private Sub BtnCh2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnCh2.Click
FormCh2.Show()
End Sub
Private Sub BtnCh3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnCh3.Click
FormCh3.Show()
End Sub
Private Sub BtnCh4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnCh4.Click
FormCh4.Show()
End Sub
Can it be done with a single command?
In your form's load event add the forms in a List(Of Form)
Private list As List(Of Form)
Private Sub Me_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Me.Load
list = New List(Of Form)
list.Add(New Form1())
'
'
'
list.Add(New Form24())
End Sub
Set your button's Tag property with the form's index and set them all to use the same click event:
Private Sub btn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn.Click
list(CType(sender, Button).Tag).Show()
End Sub
Attach all the handlers to your method and then branch behaviour based on the Select Case:
Private Sub Button_Click_Handler(sender As Object, e As EventArgs) Handles Button66.Click, Button67.Click, Button68.Click
Dim btn As Button = DirectCast(sender, Button)
Select Case btn.Name
Case Button66.Name
Dim f1 As New Form1
f1.Show()
Case Button67.Name
Dim f2 As New Form2
f2.Show()
Case Button68.Name
Dim f3 As New Form3
f3.Show()
End Select
End Sub
I have 10 panels on my form, and when you hover them, their color changes. I have 10 private subs like so...
Private Sub pnl2_MouseHover(ByVal sender As Object, ByVal e As System.EventArgs) Handles pnl2.MouseHover
pnl2.BackColor = Color.WhiteSmoke
End Sub
This code is repeated for each panel with the only difference being it's name, how can I do this more efficiently? as it is very repetitive.
Add them at the handler statement appending each by a comma. The sender object is the panel in question so cast it to change it's properties.
Private Sub pnl2_MouseHover(ByVal sender As Object, ByVal e As System.EventArgs) Handles pnl2.MouseHover, pnl3.MouseHover 'etc
Dim pnl As Panel = CType(sender, Panel)
pnl.BackColor = Color.WhiteSmoke
End Sub
I am trying to pass a value of a textbox on frmMain to a textbox on frmDepartment. I have tried the following code which I thought would work but it dosen't. I ma a new user to VB and come from a php background where it would have been a simple task of setting a seesion. Can anyone help with this? If you need to see more code, please ask. many thanks
txtDeptCustomer.Text = frmMain.txtCustomerActive.Text
In frmMain, I am getting value like this:
Dim value As Object = UserDataGridView.Rows(e.RowIndex).Cells(0).Value
txtCustomerActive.Text = CType(value, String)
Private Sub btnDepts_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDepts.Click
frmDepartment.Show()
End Sub
Which is showing in frmMain ok.
In frmDepartment I have this code
Private Sub txtDeptCustomer_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtDeptCustomer.TextChanged
'Dim customer As String
txtDeptCustomer.Text = frmMain.txtCustomerActive.Text
End Sub
instead of putting the code within the txtDeptCustomer.TextChanged sub, try putting it within the frmDepartment_load:
Private Sub frmDepartment_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
txtDeptCustomer.Text = frmMain.txtCustomerActive.Text
End Sub
or you could set the frmDepartment text box text on the frmMain button click:
Private Sub btnDepts_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDepts.Click
frmDepartment.txtDeptCustomer.Text = txtCustomerActive.Text
frmDepartment.Show()
End Sub
I have a background worker that calls a form, holding a gif animation. The purpose is to display the animation while process is underway but it should close when the process is done. But it does not close even after completion of the process. Please help.
Thanks
Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
frmAnimation.ShowDialog()
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
BackgroundWorker1.RunWorkerAsync()
Dim sqldatasourceenumerator1 As SqlDataSourceEnumerator = SqlDataSourceEnumerator.Instance
datatable1 = sqldatasourceenumerator1.GetDataSources()
DataGridView1.DataSource = datatable1
'I have tried CancelAsync, but did not work
BackgroundWorker1.CancelAsync()
frmAnimation.Dispose()
End Sub
BackgroundWorkers are intended to actually do the "work" of the background operation, so the main UI thread can continue rendering things onto the screen. I suspect you want the GetDataSources() function call to be done within the BackgroundWorker thread.
Try switching what's in your button click function and what's in the DoWork function of your BackgroundWorker. Specifically, I mean something like this:
Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
Dim sqldatasourceenumerator1 As SqlDataSourceEnumerator = SqlDataSourceEnumerator.Instance
datatable1 = sqldatasourceenumerator1.GetDataSources()
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
BackgroundWorker1.RunWorkerAsync()
frmAnimation.ShowDialog()
End Sub
And in addition, add some code to the RunWorkerCompleted event to handle what should be done upon completion of your background operation.
Private Sub BackgroundWorker1_RunWorkerCompleted(ByVal sender As Object, ByVal e As RunWorkerCompletedEventArgs) Handles BackgroundWorker1.RunWorkerCompleted
DataGridView1.DataSource = datatable1
frmAnimation.Close()
End Sub
You may also want to consider using frmAnimation.Show() instead of frmAnimation.ShowDialog() depending on if you want the procedure to be modal or modeless. You can read more about that here.
I have multiple textbox in a form. How do I know what textbox the cursor currently is?
Trying to do something like this:
If TextBox2.Focus() = True Then
MessageBox.Show("its in two")
ElseIf TextBox3.Focus = True Then
MessageBox.Show("its in three")
End If
But I think its not working.
TextBox.Focus actually assigns the focus to the given textbox. What you're looking for is TextBox.Focused. :)
In fact, all form controls have the Focused property.
I know this already has an accepted answer but I just think this method is a bit easier and should be up here for people who find this through Google or whatever.
Public focussedTextBox As TextBox
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
For Each control As Control In Me.Controls
If control.GetType.Equals(GetType(TextBox)) Then
Dim textBox As TextBox = control
AddHandler textBox.Enter, Sub() focussedTextBox = textBox
End If
Next
End Sub
This way you can then just refer to the focussedTextBox at any time. You should make sure that you check that there is a focussedTextBox before you do however becuase when the application first loads there will not be. You can do this using:
If Not focussedTextBox Is Nothing Then
...
End If
Alternatively, you could set focussedTextBox to a TextBox of your choice on form load, either by setting its value or by focussing the TextBox.
Obviously, it will not work if you are calling your code in a Button_Click because when you click the Button then the focus is itself goes to the Button which you have clicked.
You can do two things:
Make a combined Focus event for all TextBoxes and check its Sender object.
Private Sub TextBox_Focus(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox2.Enter, TextBox3.Enter
Dim currTextBox As TextBox = sender
If currTextBox.Equals(TextBox2) Then
MessageBox.Show("it's in two")
ElseIf currTextBox.Equals(TextBox3) Then
MessageBox.Show("it's in three")
End If
End Sub
OR
Take a global string variable, and set its value at each TextBox_Focus event, then check string value in the button click event.
Dim str As String
Private Sub TextBox2_Focus(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox2.Enter
str = "two"
End Sub
Private Sub TextBox3_Focus(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox3.Enter
str = "three"
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
MessageBox.Show("it's in " & str)
End Sub