vb.net ComboBox Text Changing When Left - vb.net

I'm having an issue with my ComboBoxes whereby if I type into it to get a value & then tab out the Text changes to the first item in the list with the first letter typed.
I have:
AutoCompleteMode set to SuggestAppend
AutoCompleteSource set to ListItems
DropDownStyle set to DropDownList
I add the items for the ComboBox in the Load event of the Form the ComboBox is on.
e.g. the below is code from a Load event where I populate a ComboBox that I have set up as below.
`Me.ComboBox1.Text = ""
Me.ComboBox1.Items.Add("a")
Me.ComboBox1.Items.Add("aaa")
Me.ComboBox1.Items.Add("combo")
Me.ComboBox1.Items.Add("combobox")
Me.ComboBox1.Items.Add("combobox test")
Me.ComboBox1.Items.Add("common")
Me.ComboBox1.Items.Add("common dialog")`
After running the code, if I select the ComboBox1 & type in common - common is selected in ComboBox1 but if I leave ComboBox1 the Text reverts to combo.
It gets a bit stranger as if I user the below code in the ComboBox1_Leave event procedure it throws common:
MsgBox(ComboBox1.Text)
I've also tried assigning the value of Text to a string in the ComboBox1_KeyUp event procedure & then assign that to ComboBox1.Text in the ComboBox1_Leave event procedure but that doesn't do anything.
If I put a the above MsgBox code before assigning the strings value to ComboBox1.Text then the Text value does revert to Common but this is isn't a practical solution.
I've also noticed that if I hit Enter before hitting tab it retains the correct value but again I'm don't think this is a particularly practical solution.
Does anyone have any idea what's going on here & how I can fix it?

It is absolutely necessary to have the DropDownStyle set to DropDownList?
Because if you set DropDownStyle to DropDown the selected value will be retained when you press tab or lose the focus.
If it's absolutely necessary to have it that way, you could try this.
Public Class Form2
Dim selectedTextForCombo As String = ""
Private Sub Form2_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
Me.ComboBox1.Text = ""
Me.ComboBox1.Items.Add("a")
Me.ComboBox1.Items.Add("aaa")
Me.ComboBox1.Items.Add("combo")
Me.ComboBox1.Items.Add("combobox")
Me.ComboBox1.Items.Add("combobox test")
Me.ComboBox1.Items.Add("common")
Me.ComboBox1.Items.Add("common dialog")
End Sub
Private Sub ComboBox1_LostFocus(sender As Object, e As System.EventArgs) Handles ComboBox1.LostFocus
ComboBox1.SelectedItem = selectedTextForCombo
'This is just for a visualization of your issue
'Label1.Text = selectedTextForCombo
End Sub
Private Sub ComboBox1_SelectedIndexChanged(sender As System.Object, e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged
selectedTextForCombo = ComboBox1.Text
'This is just for a visualization of your issue
'Label1.Text = selectedTextForCombo
End Sub
End Class
Warning:
This example works with the tab action.
If the users writes something that doesn't exist like "commun" the
selected value will end up being the visually selected value, in this
case: "common"

Related

parse value from datagrid to button name

I'm building a form that has many buttons, all buttons do the same thing: add 1 every time they are clicked. Every pressed button is sent to a datagridview along with the time they are pressed. Datagrid values look like this:
a_1_serv (button name), 18:05:00(time).
Sometimes I want to delete the last row. Everything works fine so far.
When I delete the last row, I want to change the text of the button (a_1_serv).
I can parse the dgv value (a_1_serv) to a variable but I can't bind it to the appropriate button name so I can control it.
Is there a way to do it?
Don't store your program state in your UI
Create a data structure to hold the information, and let the DataGridView be a "view", not treating it as a variable. You will save yourself headaches vs using the UI as a variable.
That said, create a class to represent your information
Public Class Data
Public Sub New(button As Button, time As DateTime)
Me.Button = button
Me.Time = time
End Sub
<System.ComponentModel.Browsable(False)>
Public Property Button As Button
Public ReadOnly Property Text As String
Get
Return Button.Name
End Get
End Property
Public Property Time As DateTime
End Class
And your code can manipulate the data in a variable off the UI. Bind the data to the DataGridView for display.
Private datas As New List(Of Data)()
Private Sub Button_Click(sender As Object, e As EventArgs) Handles Button1.Click, Button2.Click, Button3.Click, Button4.Click
addButton(DirectCast(sender, Button))
End Sub
Private Sub RemoveLastButton_Click(sender As Object, e As EventArgs) Handles RemoveLastButton.Click
removeLast()
End Sub
Private Sub addButton(b As Button)
datas.Add(New Data(b, DateTime.Now))
bindData()
End Sub
Private Sub removeLast()
Dim b = datas.Last.Button
b.Text = "new text" ' change to whatever
datas.RemoveAt(datas.Count - 1)
bindData()
End Sub
Private Sub bindData()
DataGridView1.DataSource = Nothing
DataGridView1.DataSource = datas
End Sub
This does exactly what you stated but there may be inconsistency in these two bits of information you provided: a_1_serv (button name) and I want to change the text of the button .... This changes the button text but not the name. The name is displayed in the grid. You can change the data class to display the text or whatever. But the point is this approach will keep your data off the UI and you won't need to look up the control by name anymore.

Visual Basic - Displaying a combo box entry over a textbox

to keep it short and simple, I am attempting to display a number selected through a combo box on a second form through a label.
Here are the bits that are relevant to the issue I am having:
for i = 1 To 31
cmb_days.Items.Add(i)
next
' Populating combo box
days = cmb_days.text
frm_result.lbl_renting = "Renting for " & days & " Days"
I have tried using other variants such as cmb_days.selecteditem to no avail
I am also kinda having issues with like telling my code to do things with whatever number is actually selected in the combo box, idk I am veryyyyy new
That looks more or less correct.. But the question is where your call to update the label occurs in your code...
This is a minimal working example, with just a ComboBox on a form:
Public Class Form1
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
For i = 1 To 31
ComboBox1.Items.Add(i)
Next
End Sub
Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
Me.Text = ComboBox1.Text
End Sub
End Class
The update of the label (in this case the text of the form, but it works exactly the same with a label on a different form) occurs in the SelectedIndexChanged event of ComboBox1.
If you copied your code straight from the project, you haven't had time to select anything yet, so the Text property will be empty.

vb.net add values from listbox to textbox via drag&drop AND via double click

I'm struggling with some functionality I want to use on my Windows form.
( Just for info, this is for an AutoDesk Inventor AddIn. )
This is my form layout.
The current workflow
The top 4 list-boxes are filled with available parameter names. The user chooses the parameter(s) he/she wants to use and drags and drops it into one of the driving parameter text-boxes ( marked with the <1> label ).
The code that relates to the drag and drop operations
Private Sub lstTemp_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) _
Handles lbModelParameters.MouseDown,
lbUserParameters.MouseDown,
lbReferenceParameters.MouseDown,
lbLinkedParameters.MouseDown
' In order to access a specific item in a listbox.itemcollection, you must think of it
' as an array of data or a collection and access it in the same manner by always
' letting VB know which item you intend to use by identifying it with its index location
' within the collection. And this is better than taking up basket weaving :-)
lbModelParameters.DoDragDrop(sender.Items(sender.SelectedIndex()).ToString, DragDropEffects.Move)
End Sub
Private Sub txtTemp_DragEnter(ByVal sender As Object, ByVal e As System.Windows.Forms.DragEventArgs) _
Handles tbParameter1.DragEnter,
tbParameter2.DragEnter,
tbParameter3.DragEnter,
tbParameter4.DragEnter,
tbParameter5.DragEnter
'Check the format of the incoming data and accept it if the destination control is able to handle
' the data format
'Data verification
If e.Data().GetDataPresent(DataFormats.Text) Then
e.Effect() = DragDropEffects.Move
Else
e.Effect() = DragDropEffects.None
End If
End Sub
Private Sub txtTemp_DragDrop(ByVal sender As Object, ByVal e As System.Windows.Forms.DragEventArgs) _
Handles tbParameter1.DragDrop,
tbParameter2.DragDrop,
tbParameter3.DragDrop,
tbParameter4.DragDrop,
tbParameter5.DragDrop
'This procedure receives the dragged data once it passes the data verification handled by the DragEnter method
'Drops the data onto the destination control
sender.Text() = e.Data().GetData(DataFormats.Text).ToString()
End Sub
New functionality
Now I would like to decrease the user mouse movement for ergonomic reasons and speed. But I would also like to keep to the drag and drop functionality. As it can overwrite a value that has already been added by the user.
I would like to be able to DoubleClick a item in the listbox, and that item should be added to the first empty textbox. I named my textboxes with a number so it's easy to loop over them all to check if it's empty.
I tried doing it with this code, but my double click event never gets fired. It always goes to the drag and drop. How do you do handle this, that the double click gets fired instead of drag drop?
Private Sub ParameterAddDoubleClick(sender As Object, e As EventArgs) _
Handles lbModelParameters.DoubleClick,
lbUserParameters.DoubleClick,
lbReferenceParameters.DoubleClick,
lbLinkedParameters.DoubleClick
Dim oControl As Windows.Forms.ListBox
oControl = DirectCast(sender, Windows.Forms.ListBox)
' Add line in likedparameters listbox
If oControl.SelectedIndex <> -1 Then
' Loop trough all the controls to see if one is empty
' if it's empty add parameter, else go to next
' if all textboxes are used do nothing.
For i = 1 To 6
Dim oTextbox As Windows.Forms.TextBox =
CType(gbDrivingParameters.Controls("tbParameter" & i),
Windows.Forms.TextBox)
If oTextbox.TextLength = 0 Then
' Add the sender item into the linked listbox
oTextbox.Text = oControl.Items.Item(oControl.SelectedIndex)
End If
Next
End If
End Sub
I hope my question is clear, and well prepared. If there is additional information needed, please let me know in a comment.
Mousedown triggers the DoDragDrop, wich stops the doubleclick-event from firing.
To identify if a user doubleclicks or wants to perform a dragdrop, consider the following:
Private Sub ListBox1_MouseDown(sender As Object, e As MouseEventArgs) Handles ListBox1.MouseDown
' Determine whether we are performing a drag operation OR a double click
If e.Clicks = 1 Then
TextBox1.Text = "mousedown"
Else
TextBox1.Text = "dblclick"
End If
End Sub

Edit Update DatagridView VB.Net (No Database)

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)

Issue detecting checkbox state in DataGridView

I have a DataGridView control in a .Net application that contains a checkbox column. I would like for the user to be able to edit the checkboxes. The issue that I am running into is that I cannot detect the state of the checkbox after the user checks it.
If the checkbox was originally checked, then it will return checked as soon as the DataGridViewCheckBoxCell gets focus. But, if I click on the checkbox again and unchecks it, then it still returns checked. From that point on, it will always return checked regardless of the actual state of the checkbox until it looses focus and gains it again.
Likewise, if the checkbox was originally unchecked, then when it gets focus it will return unchecked in the click event regardless of what the state of the checkbox actually is.
Here is my code.
Private Sub grdTemplates_CellContentClick(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles grdTemplates.CellContentClick
Dim strValue As String = ""
Try
If Me.grdTemplates.Columns(e.ColumnIndex).Name = "colCurrentTemplate" Then
'The user clicked on the checkbox column
strValue = Me.grdTemplates.Item(e.ColumnIndex, e.RowIndex).Value
'THIS VALUE NEVER CHANGES WHILE THE DataGridViewCheckBoxCell HAS FOCUS
Me.lblTemplates.Text = strValue
End If
Catch ex As Exception
HandleError(ex.ToString)
End Try
End Sub
Thanks in advance,
Mike
Include this in your code:
Sub dataGridView1_CurrentCellDirtyStateChanged(ByVal sender As Object, ByVal e As EventArgs) Handles dataGridView1.CurrentCellDirtyStateChanged
If dataGridView1.IsCurrentCellDirty Then
dataGridView1.CommitEdit(DataGridViewDataErrorContexts.Commit)
End If
End Sub
Source: http://msdn.microsoft.com/en-us/library/system.windows.forms.datagridview.currentcelldirtystatechanged.aspx