I have a listbox which gradually gets populated with orders as the program is used. However, I want to open a separate form when any item within the listbox is double clicked.
handles lstbox.selectedindexchanged
Isn't what I'm looking for and neither is:
handles lstbox.doubleclick
As they just run whenever any index is clicked once or anywhere on the control is double clicked, respectively.
Any ideas?
Nothing built-in on the WinForms ListBox control, so use the MouseDoubleClick event to simulate it:
Private Sub ListBox1_MouseDoubleClick(sender As Object, e As MouseEventArgs) Handles ListBox1.MouseDoubleClick
Dim index As Integer = ListBox1.IndexFromPoint(e.Location)
If index > -1 AndAlso index = ListBox1.SelectedIndex Then
MessageBox.Show(ListBox1.SelectedItem.ToString)
End If
End Sub
Related
I've just starting using ListView control in VS2019.
I'm sure there's a simple solution, but I can't figure out how to set the focus on the control like I can with most other controls.
I want the ListView to be focused when the form loads, and then I want to programmatically focus an item in the ListView.
I know how to focus a particular item using ListView1.FocusedItem.Index, but I can't focus the actual control.
I have tried both ListView1.Select() and ListView1.Focus() but these seem to do nothing.
What am I missing!?
Thanks
EDIT
As pointed out below, the control is actually focused using ListView1.Select() it's just not focused in the same way I'd expect, for example, a ListBox to be focused - ie, with a particular item in the list highlighted.
How would you best focus the ListView and highlight a particular item?
I have tried this in a command button on the form, but it doesn't do anything. Though it works correctly AFTER I click an Item in the ListView.
ListView1.Select()
If (ListView1.SelectedItems.Count > 0) Then
ListView1.Items(4).Selected = True
End If
listview1.focus()
For I as Integer = 0 to ListView1.Items.Count - 1
If ListView1.Items(i).Text = "youritemtexthere" then
ListView1.Items(i).Selected = true
End If
End For
or if you have the index but not a known text just do:
listview1.focus()
ListView1.Items(index).Selected = true
ListView1.Select works, you probably just don't see that the ListView has focus. You can verify this by checking the GotFocus and LostFocus events on the ListView:
Private Sub ListView1_GotFocus(sender As Object, e As EventArgs) Handles ListView1.GotFocus
Me.Text = "Got Focus"
End Sub
Private Sub ListView1_LostFocus(sender As Object, e As EventArgs) Handles ListView1.LostFocus
Me.Text = "Lost Focus"
End Sub
This simply updates your Form's title to "Got Focus" or "Lost Focus". You can force the focus in your Form Load event:
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
ListView1.Items.Add("a")
ListView1.Items.Add("b")
ListView1.Items.Add("c")
ListView1.Select()
End Sub
In my program (Winforms), i use usercontrols as pages. I do this in the following way:
I have a panel on my Form1 in which i load usercontrols, on these usercontrols are my actual controls (buttons, labels, checkboxes etc). So actually i'm using the user controls as "sub" pages in my form.
The usercontrols are declared at the start of runtime, so they are "live" when i load them into the panel. This has allways worked fine, untill i ran into a problem yesterday.
Yesterday I used a datagridview on one of those usercontrols and during the ParentChanged of this control i call a Sub which changes the backcollor of this data grid view. (The sub itself is a public sub which is located in a module)
Like this:
Private Sub Init_ParentChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.ParentChanged
GetRecipe(RecipeDGV, "Bla")
End Sub
Public Sub GetRecipe(ByVal Data As DataGridView, ByVal RecipeID As String)
For r As Integer = 0 To Recipe_Mem.Rows.Count - 1
For c As Integer = 0 To Recipe_Mem.Columns.Count - 1
Data(c, r).Style.BackColor = getPresetColorByID(CInt(Data(c, r).Value))
Data(c, r).ToolTipText = getPresetNameByID(CInt(Data(c, r).Value))
NEXT
NEXT
End Sub
When i run my program, i can see that my dgv gets the data from the database (which happens in the same Sub). But there is no color change in the cells.
Now, something i've noticed is that when i add a button to the user control, and use the click event of this button to call the same sub for the coloring, it does work).
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
GetRecipe(RecipeDGV, "Bla")
End Sub
Any idea why this works on a button click event, but it doesn't in the usercontrol parent changed event? it looks like during the parent changed event there is some kind of repaint event of the dgv. how do i solve this?
Have you tried wrapping the gridview in an ajax control ( with triggers on the ParentChanged event?
I'm a little puzzled by the "RecipeID" argument being passed as it isn't used.
Good day everyone.
I need your help in this project I am into (a Visual Basic program with no database.) It just contains a Datagridview, a Textbox, and three buttons (an "Add" Button, a "Edit" and an "Update" Button).
1 . Is there any way (like using "for loop") to automatically assign DataGridView1.Item("item location") to the one edited and be updated?
2 . Or is it possible to just click an item in the Datagridview then it will be edited at that without passing it to a Textbox, and to be updated at that.
The DataGridViewCellEventArgs variable (e in the method stub the designer will generate for you) of the double click event of the cell has RowIndex and ColumnIndex properties which refer to the position of the cell you clicked.
Save those (in a class variable possibly or a local one if that's all you need) and then refer to them when you update the cell in your DataGridView, possibly like this MyDataGridView.Item(e.ColumnIndex, e.RowIndex) or MyDataGridView.Rows(e.RowIndex).Cells(e.ColumnIndex) where e is the variable from the double click event handler.
For you cell double click event you could have something like this:
Private Sub DataGridView1_CellDoubleClick(sender As Object, e As DataGridViewCellEventArgs) Handles DataGridView1.CellDoubleClick
Using myEditor As New frmCellEditor(Me.DataGridView1.Item(e.ColumnIndex, e.RowIndex).Value)
If myEditor.ShowDialog() = DialogResult.OK Then
Me.DataGridView1.Item(e.ColumnIndex, e.RowIndex).Value = myEditor.NewCellValue
End If
End Using
End Sub
This will call a new instance of your editor and get a value from you. For the purpose of this demo I have made a form like this:
Public Class frmCellEditor
Public NewCellValue As Integer
Public Sub New(ByVal CurrentCellValue As Object)
InitializeComponent()
Me.TextBox1.Text = CStr(CurrentCellValue)
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Me.NewCellValue = CInt(Me.TextBox1.Text)
Me.DialogResult = DialogResult.OK
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
Call Me.Close()
End Sub
End Class
Which just has two buttons (Button1 = OK, Button2 = Cancel). When you click OK, it just returns the value 1 which then gets set as the value of the cell.
This is a VERY simplistic example, but it should provide you the basics of what you are trying to do.
UPDATE:
I updated the code for the editor interface so it will include handling for passing the value back and forth from the form with your datagridview.
In your project, make a new form called frmCellEditor. This forms has to have two buttons and a textbox (Make sure that the programmatic names match!). Replace the code with the code listed above. You will have to add Imports System.Windows.Forms above the class as well.
Amend the event handler for the cell double click event of your datagrid to pass the cell value when frmCellEditor is constructed (the line going ... New frmCellEditor(...).
How many columns does your DataGridView has?
Based on how you populate your DataGridView, I'll assume only 1.
Declare this on top of your form
Dim i as Integer
On your btnUpdate_Click Event (Just combine your Edit and Update button into One)
SELECT CASE btnUpdate.Text
Case "Update"
With DataGridView1
'Check if there is a selected row
If .SelectedRows.Count = 0 Then
Msgbox "No Row Selected for Update"
Exit Sub
End If
i = .CurrentRow.Index 'Remember the Row Position
Textbox1.Text = .item(0 ,i).value 'Pass the Value to the textbox
.Enabled = False 'Disable DataGridView to prevent users from clicking other row while updating.
btnUpdate.Text = "Save"
End With
Case Else 'Save
DatagridView1.Item(0,i).Value = Textbox1.Text
btnUpdate.Text = "Update"
END SELECT
Thanks for those who contributed to finding answers for this thread. I have not used your solutions for now (maybe some other time). After some research, I've found an answer for problem 2 (more user friendly at that):
2 . Or is it possible to just click an item in the Datagridview then
it will be edited at that without passing it to a Textbox, and to be
updated at that.
Here's what i did:
in Private Sub Form1_Load, just add:
yourDataGridView.EditMode = DataGridViewEditMode.EditOnEnter
in Private Sub yourDataGridView_(whatever event here: DoubleCellClick, CellContentClick, etc.) add:
DataGridView1(e.ColumnIndex, e.RowIndex).[ReadOnly] = False
DataGridView1.BeginEdit(False)
I have a windows form project with a main form. There is a textbox leave event that opens a new form. In that new forms load event i have a combobox item loop that populates the combobox items. It works perfectly fine if run on the main form but doesnt work on the second form. Why doesn't the comboboxes on the secondary form populate when that form is opened via a textbox_leave event from the main form?
this is the leave event
Private Sub tbChartTitle_Leave(sender As Object, e As System.EventArgs) Handles tbChartTitle.Leave
If Not tbChartTitle.Text = Nothing Then
frmTitleAttributes.Show()
End If
End Sub
This is the code that populates one of the comboboxes on the second form (it works if run on a combobox on the main form)
Private Sub frmTitleAttributes_Load(sender As Object, e As System.EventArgs) Handles Me.Load
InitializeComponent()
AddFonts()
End Sub
Private Sub AddFonts()
' Get the installed fonts collection.
Dim allFonts As New Drawing.Text.InstalledFontCollection
' Get an array of the system's font familiies.
Dim fontFamilies() As FontFamily = allFonts.Families
' Display the font families.
For i As Integer = 0 To fontFamilies.Length - 1
cbxTitleFonts.Items.Add(fontFamilies(i).Name)
Next
End Sub
make sure that the Load handler is hit after you show your form (use break point)
also you can try to call it in the Shown event
Private Sub frmTitleAttributes_Shown(sender as Object, e as EventArgs) _
Handles frmTitleAttributes.Shown
AddFonts()
End Sub
I created a groupbox and then populate it with buttons during runtime. I also created a button, say Button1 to loop through the groupbox and delete those buttons. Here's my code
for Button1:
Public Sub removeControls()
For Each ctrl As Control In GroupBox1.Controls
GroupBox1.Controls.Remove(ctrl)
ctrl.Dispose()
Next
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
removeControls()
End Sub
When executed, it only removes some of the controls inside the GroupBox1, not all. Can you explain what is missing in my code to make it work? Thanks.
When you delete controls in a For Each loop, you're actually modifying the collection that you're trying to loop through. When you remove the first item in the collection, the second item moves up to become the first. But now, when you reach the second index of your loop, the third item is in its place. You've effectively skipped removing the second item, and only removed the first and third. And so on through the entire loop.
Instead, you need to loop through the controls in reverse order and remove the item at each index. By starting to removing items from the end, you won't affect the order or position of the items.
So, just change your method to the following:
Public Sub RemoveControls()
For i As Integer = (GroupBox1.Controls.Count - 1) To 0 Step -1
Dim ctrl As Control = GroupBox1.Controls(i)
GroupBox1.Controls.Remove(ctrl)
ctrl.Dispose()
Next i
End Sub
You are changing the collection as you are itterating through it, and that should not be done.
Rather use something like
For i As Integer = GroupBox1.Controls.Count - 1 To 0 Step -1
Dim ctrl As Control = GroupBox1.Controls(i)
GroupBox1.Controls.Remove(ctrl)
ctrl.Dispose()
Next