Unselect/deselect row in DataGridView on click - vb.net

I'm in the process of migrating VB6 code to VB.NET and we're up to the VS2013 stage, using .NET 4.5.2. In the original code, there are FlexGrids that allow row deletion on double-click and row selection/deselection on single click. I've got double-click going fine, it deletes the row and sets all rows as deselected (because double-clicking the header cell was re-ordering the rows and selecting a row, without a click on the row, and then deleting the now selected row). I don't know if that's relevant, but I've included it just in case.
I've looked here but it doesn't help because this behavior is expected and I don't know if the client will want to hear that everyone has to be re-trained to use the CTRL+click method to deselect. If that's how it must be, then so be it, but I have to try to make this work.
Using the cell click event to do something like this
Private Sub grdSelectedOps_CellClick(sender As Object, e As DataGridViewCellEventArgs) Handles grdSelectedOps.CellClick
If Not grdSelectedOps(e.ColumnIndex, e.RowIndex).Selected Then
grdSelectedOps(grdSelectedOps.CurrentCell.ColumnIndex, grdSelectedOps.CurrentCell.RowIndex).Selected = True
Else
grdSelectedOps(grdSelectedOps.CurrentCell.ColumnIndex, grdSelectedOps.CurrentCell.RowIndex).Selected = False
End If
End Sub
doesn't work, because if you've clicked the cell you've selected it, so it always immediately deselects it. Multi-select is off. Is this possible?

Your Question is answered Here:
Toggle Selection in DataGrid
It is C# so here is the equivalent VB.NET Code is:
REM Keeps track of selection status
Private selectionChanged As Boolean
REM Fires Second
Private Sub dataGridView1_CellClick(sender As Object, e As DataGridViewCellEventArgs)
If Not selectionChanged Then
dataGridView1.ClearSelection()
selectionChanged = True
Else
selectionChanged = False
End If
End Sub
REm Fires first
Private Sub dataGridView1_SelectionChanged(sender As Object, e As EventArgs)
selectionChanged = True
End Sub
You may want to override the DataGrid Control to provide this functionality internally, but that is up to you.

Related

Unchecking a Previously Selected Checkbox when another checkbox is checked

My form has 3 checkboxes available to the User. When the User mistakenly checks one Checkbox and realizes the mistake then checks the correct Checkbox, I need the incorrect checked Checkbox to Uncheck automatically.
I have diligently searched the web but have been unable to find any sites that offer answers for VB 2010. Mostly they provide solutions for HTML, Excel, Java, etc.
Private Sub BeginnerForm_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
StartupForm.Close()
If Me.CheckBox1.Checked Then
Me.CheckBox2.Checked = False
Me.CheckBox3.Checked = False
ElseIf Me.CheckBox2.Checked Then
Me.CheckBox1.Checked = False
Me.CheckBox3.Checked = False
ElseIf Me.CheckBox3.Checked Then
Me.CheckBox1.Checked = False
Me.CheckBox2.Checked = False
End If
End Sub
The results of this code is that it does not uncheck the Checkbox(es). I get no error code, it just does not UNCHECK the Checkbox(es). I have also tried other code entries such as Me.Checkbox2.CheckState.Checked = CheckState.Unchecked to no avail. Trusting you can steer me in the right direction to UNCHECK a Checkbox when another Checkbox is CHECKED.
First of all, as mentioned by daShier, you place the code in the wrong event handler. Since you want to uncheck the other checkboxes when one is being checked, you must put the code in the either Click or CheckChanged event handler of all your checkboxes that take part in this selection logic. I would suggest to put in the CheckChanged event since it will be triggered even when your checkbox check state is changed through code in addition to through mouse or keyboard actions.
' declare variable to keep track of the previous selected checkbox
Dim prevSelectedCheckBox As CheckBox
' all checkboxes to be controlled are handled by this event handler
Private Sub CheckBoxes_CheckedChanged(sender As Object, e As EventArgs) Handles CheckBox1.CheckedChanged, CheckBox2.CheckedChanged, CheckBox3.CheckedChanged
' first, identify which checkbox is triggering this event
Dim this As CheckBox = DirectCast(sender, CheckBox)
' if this event is triggered when this checkbox is being checked
If this.Checked Then
' if there is a checkbox previously selected/checked
If prevSelectedCheckBox IsNot Nothing Then
prevSelectedCheckBox.Checked = False ' uncheck it
End If
' now this checkbox is currently the checked one, save it to the variable
prevSelectedCheckBox = this
' if event is triggered by unchecking this checkbox, and this checkbox is the previously checked checkbox
ElseIf this.Equals(prevSelectedCheckBox) Then
' clear the variable since now, there is no checkbox is being checked
prevSelectedCheckBox = Nothing
End If
End Sub
However, if user can only select one option among the options represented by the checkboxes, you better use radio button instead.
It appears you are processing the code in the wrong handler. You are changing things when closing the form. Try moving the code to the CheckBoxx.CheckedChanged handlers:
Private Sub CheckBox1_CheckedChanged(sender As Object, e As EventArgs) Handles CheckBox1.CheckedChanged
If CheckBox1.Checked Then
CheckBox2.Checked = False
CheckBox3.Checked = False
End Sub
UPDATE: I realize that your original code that I copied and pasted would cause a loop since the changing of the checkbox states would trigger the other routines. It's not necessary since you only need clear the other boxes if the box your user is clicking is checked.
You will need to add similar code to CheckBox2.CheckedChanged and CheckBox3.CheckedChanged as well.
Also, I should point out that you are trying to make checkboxes act as radio buttons. Why not replace the checkbox controls with radio buttons instead so that VB handles the one-only behavior for you?

How to create something similar to google style currency converter with VB.NET

Ok I have a bit of a weird question here. I have a program similar to a currency converter (it performs a mathematical function in order to produce a value to go in another textbox). What I want it to be able to do is identify the last textbox that you edited (there are 4) and then update the rest based on what you have inputted, the user then must be able to change a different textbox to change all of them.
If anyone can get me started on how to do it or even some sample code that would be much appreciated, thanks!
Sorry if I'm not making sense, just have a look at the google currency converter and think that with two more editable boxes.
This might be what you want if I understand you correctly.
In the form class, you have a variable called lastTextBoxChangedName which keeps track of which text box was the last to be edited.
Next there is an event handler which will fire when any of the four TextBoxes are changed. This merely updates lastTextBoxChangedName.
When you have finihed editing a textbox, and tab to the next one or click on something that causes a TextBox to lose input focus, the next event handler executes. This looks at lastTextBoxChangedName to see which was the last edited TextBox and you can insert your update code to replace the comments in the Select Case block.
Public Class Form1
Dim lastTextBoxChangedName As String
Private Sub TextBox_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged, TextBox2.TextChanged, TextBox3.TextChanged, TextBox4.TextChanged
lastTextBoxChangedName = sender.name
End Sub
Private Sub TextBox1_LostFocus(sender As Object, e As EventArgs) Handles TextBox1.LostFocus, TextBox2.LostFocus, TextBox3.LostFocus, TextBox4.LostFocus
updateTextBoxes()
End Sub
Private Sub updateTextBoxes()
Select Case lastTextBoxChangedName
Case "TextBox1"
'do updates appropriate to textbox1 changed
Case "TextBox2"
'do updates appropriate to textbox2 changed
Case "TextBox3"
'do updates appropriate to textbox3 changed
Case "TextBox4"
'do updates appropriate to textbox4 changed
End Select
End Sub
End Class
However, if you already have separate event handlers for each TextBox, don't add that first event handler for TextBox_TextChanged, just add the line ..
lastTextBoxChangedName = sender.name
into each handler.

Show ContextMenuStripItem without clicking off the current cell

I'm using an UltraGrid which has a ContextMenuStrip with 2 items. These are shown when right-clicking an UltraGridCell.
However, in order to show them, the user has to first click off the cell to take it out of edit mode, then right click on it to show the ContextMenuStripItems.
This has become confusing and irritating to the user, so I was wondering if there is any way that it can be changed to show them when right clicking whilst still in edit mode?
I've tried this to take it out of edit mode after a key is pressed, but it doesn't work.
Private Sub ugComm_keyup(sender As Object, e As KeyEventArgs) Handles ugComm.KeyUp
ugComm.UpdateData()
If ugComm.ActiveCell.IsInEditMode = True Then
ugComm.ActiveCell.Row.Update()
End If
End Sub
I also tried something in the MouseClick that was suggested on the Infragistics forums, but again it didn't work.
Is there any way that a user right-clicking a cell that is in edit mode can bring up the ContextMenuStripItems rather than this menu?
The above image shows what is currently show when right-clicking a cell in edit mode (The cell is the bottom right white cell). I don't want this to appear, but the CMS instead.
EDIT
I've tried the suggestions in the current answers, but neither of those worked for me. Possibly because the grids are a slightly older version?
My most recent effort was done with the following code:
Private Sub ugComm_MouseDown(sender As Object, e As MouseEventArgs) Handles ugComm.MouseDown
If e.Button = Windows.Forms.MouseButtons.Right Then
Me.cmCommRate.Show(mouseX, mouseY)
End If
End Sub
But this wasn't triggered until the cell was no longer in edit mode.
NEITHER OF THE ANSWERS BELOW RESOLVE THE ISSUE. STILL NEEDS AN ANSWER
When any cell of the grid enters in edit mode a TextBox is drawn over the cell. The nice part here is this text box is reused for all the cells in the grid. When you right click on the cell in edit mode the default context menu, that comes from MS, shows. What you need to do is get this text box and assign it your context menu strip. You can do this by handling ControlAdded event of the grid like this:
' create a field to store the TextBox
Private cellTextBox As TextBox
Private Sub grid_ControlAdded(sender As Object, e As ControlEventArgs) Handles grid.ControlAdded
' Check if added control is TextBox
If TypeOf e.Control Is TextBox Then
' If added control is TextBox store it in your private field and set its ContextMenuStrip
If Me.cellTextBox Is Nothing Then
Me.cellTextBox = DirectCast(e.Control, TextBox)
Me.cellTextBox.ContextMenuStrip = Me.ctx
End If
End If
End Sub
I have tried to write an event handler for the MouseUp event with this code
Private Sub grid_MouseUp(sender As Object, e as MouseEventArgs) Handles grid.KeyUp
grid.PerformAction(UltraGridAction.ExitEditMode)
grid.ContextMenuStrip.Show()
End Sub
and it works.
The ContextMenuStrip was added in code with this text (as example)
ContextMenuStrip ctx = new ContextMenuStrip()
ctx.Items.Add("Test1")
ctx.Items.Add("Test2")
ctx.Items.Add("Test3")
grid.ContextMenuStrip = ctx

How to make a KeyDown work twice

I am working on a little story type thing in visual basic. Nothing too complicated but i have run into a problem. I am trying to make a pause feature. I have it all working to when i press escape, the form goes into a menu type thing. The only problem is that it only works once. The first press works, but if i hit continue, it continues from where i left off. But if i press it again, nothing happens. Here is the code i am using:
Private Sub Story_KeyDown(sender As Object, e As KeyEventArgs) Handles Me.KeyDown
If e.KeyCode = Keys.Escape Then
Text.Hide()
Background.Hide
ContinueButton.Show
OptionsButton.Show
End If
End Sub
Is there any way for me to make this work more than just once? I am using a KeyDown event in a private sub.
Hope this made sense, but thanks for any help guys!
You're using Form.KeyPreview = true to capture the form keystrokes. I think Text.Hide() or one of Show operations could be the problem such as getting the TabStop's out of order or leaving a gap in the tab sequence.
Try resetting the controls or using SendKeys to reset the tab sequence index (to the approriate a control to have focus), For example, Tab forward and Alt Tab back:
SendKeys.Send("{TAB}");
or
SendKeys.Send("%{TAB}");
Ref:
http://msdn.microsoft.com/en-us/library/system.windows.forms.sendkeys.send(v=vs.110).aspx
Using a class level boolean as toggle should work:
Dim Hide As Boolean = False
Private Sub Story_KeyDown(sender As Object, e As KeyEventArgs) Handles Me.KeyDown
If e.KeyCode = Keys.Escape Then
Hide = Not Hide
If Hide Then
Text.Hide()
Background.Hide
ContinueButton.Show
OptionsButton.Show
Else
Text.Show()
Background.Show
ContinueButton.Hide
OptionsButton.Hide
End If
End Sub
If nothing else helps, you can always have a private class-level variable like _processingKeyDown, set to True at handler start, and then to False when done. The first line in the handler would be:
If _processingKeyDown Then Return

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)