I have wanted to ask my problem.
I make 3 buttons, button 1, 2 and 3. so when I click one button automatic button changes color. I'm using code like this
For Each ctrl As Control In frm.Controls
If ctrl = button Then
ctrl.backcolor = color.red
End If
Next
but still error. please help me
The right code would be:
For Each ctrl As Control In frm.Controls
If TypeOf ctrl Is Button Then
DirectCast(ctrl,Button).BackColor = Color.Red
End If
Next
Use following code :
For Each ctrl As Control In Controls
If TypeOf ctrl Is Button Then
ctrl.BackColor = Color.Red
End If
Next
What you are doing wrong is compare an instance with a type. What you need to do is compare Type of an instance to another Type.
This isn't the best way. Have a look at the below option.
Sub buttons_click(sender as Object, e as event) Handles button1.Click,
_ button2.Click,
_ button3.Click
sender.backcolor = color.red
End Sub
Sorry if the syntax is a bit off, it's a while since i've done vb.
Hope this helps.
Related
Public Class Form1
Dim controlNames() As String = {"Tea", "Cola", "Coffee", "Orange", "Water", "VanillaCone", "VanillaShake", "StrawberryShake", "ChocolateMilkshake", "Fries", "Salad", "Hamburger", "OnionRings", "ChickenSalad", "FishSandwich", "CheeseSandwich", "ChickenSandwich"}
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
For Each ctrl As Control In Me.Panel2.Controls
If TypeOf ctrl Is TextBox Then
ctrl.Enabled = False
End If
Next
End Sub
Private Sub Timer1_Tick(sender As Object, e As EventArgs)
For i = 0 To 16
For Each ctrl As Control In Me.Panel2.Controls
If TypeOf ctrl Is CheckBox Then
If ctrl.Name = "chk" & controlNames(i) Then
If DirectCast(ctrl, CheckBox).CheckState = CheckState.Checked Then
If TypeOf ctrl Is TextBox Then
If ctrl.Name = "txt" & controlNames(i) Then
ctrl.Enabled = True
End If
End If
End If
End If
End If
Next
Next
End Sub
I have a VB.NET assignment and I am attempting to enable textboxes based on whether or not the checkbox with the same name was checked.
This is my code so far and it obviously doesn't work. What I want to do essentially:
All textboxes start as disabled. Then, textboxes only get enabled if the corresponding checkboxes are checked. For example, if chkTea is checked, then it enables txtTea.
I am aware I can copy paste something like "if chkTea = checked then txt.tea = enabled". I do not want to do this as this seems like a poor way to go about this. I want to know if I can do something like my barely readable code shows.
If you're renaming all your controls to something different to the default name with a number, this code should work just fine.
You dont need a timer, it just fires when any of the CheckBoxes have their state changed.
In the example code, I've created a CheckedChanged handler and set it to handle some of the CheckBoxes (You'll want to add all those you want to handle). If you click on any of these CheckBoxes, the handler will fire. The handler then passes which checkbox has been changed to the SyncTextBoxWithCheckBoxState method. This then finds the matching textbox using the FindMatchingCheckBox method and sets the .Enabled state of the Text box to the same as the .Checked state of the CheckBox
Private Sub chkTea_CheckedChanged(sender As Object, e As EventArgs) Handles chkTea.CheckedChanged, chkCoffee.CheckedChanged, chkCola.CheckedChanged, chkOrange.CheckedChanged, chkTea.CheckedChanged, chkVanillaCone.CheckedChanged, chkVanillaCone.CheckedChanged, chkWater.CheckedChanged
SyncTextBoxWithCheckBoxState(CType(sender, CheckBox))
End Sub
Private Sub SyncTextBoxWithCheckBoxState(chkBox As CheckBox)
Dim txtBox As TextBox = FindMatchingTextBox(chkBox)
txtBox.Enabled = chkBox.Checked
End Sub
Private Function FindMatchingTextBox(chkbox As CheckBox) As TextBox
For Each ctrl As Control In Panel2.Controls
If ctrl.GetType Is GetType(TextBox) And ctrl.Name.Contains(chkbox.Name.Substring(3)) Then
Return CType(ctrl, TextBox)
End If
Next
Return Nothing
End Function
EDIT
To have the code target more than one panel, add all the checkboxes you want to detect to the event handler like before, and in the FindMatchingTextBox method, just add another loop around the existing one to loop through each panel. Like so ..
Private Function FindMatchingTextBox(chkbox As CheckBox) As TextBox
'This is the new loop which loops through the two panels. It's
'a bit quick and dirty, but it works
For Each pnl As Panel In New Panel() {Panel2, Panel3}
'In this line note that the reference to Panel2 now refers to pnl
For Each ctrl As Control In pnl.Controls
If ctrl.GetType Is GetType(TextBox) And ctrl.Name.Contains(chkbox.Name.Substring(3)) Then
Return CType(ctrl, TextBox)
End If
Next
'End point of the new loop
Next
Return Nothing
End Function
After you've looped through each checkbox, you are only concerned with that checkbox, so when you find the correct checkbox, you need to then RELOOP back through all the controls on the form checking if they are the corresponding textbox.
Something like the below should work, or at the very least start you off down the right path:
Dim controlNames() As String = {"Tea", "Cola", "Coffee", "Orange", "Water", "VanillaCone", "VanillaShake", "StrawberryShake", "ChocolateMilkshake", "Fries", "Salad", "Hamburger", "OnionRings", "ChickenSalad", "FishSandwich", "CheeseSandwich", "ChickenSandwich"}
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
For Each ctrl As Control In Me.Panel2.Controls
If TypeOf ctrl Is TextBox Then
ctrl.Enabled = False
End If
Next
End Sub
Private Sub Timer1_Tick(sender As Object, e As EventArgs)
For i = 0 To 16
For Each ctrl As Control In Me.Panel2.Controls
If TypeOf ctrl Is CheckBox Then
If ctrl.Name = "chk" & controlNames(i) Then
If DirectCast(ctrl, CheckBox).CheckState = CheckState.Checked Then
For Each ctrl As Control In Me.Panel2.Controls
If TypeOf ctrl Is TextBox Then
If ctrl.Name = "txt" & controlNames(i) Then
ctrl.Enabled = True
End If
End If
Next
End If
End If
End If
Next
Next
End Sub
I created a simple TableLayoutPanel (6 by 6) with buttons in each cell. I have a click handler that executes whenever any of the button is pressed (in my case, change color of the button from red to green)
see eg.
But now I need to change the color of the button next to the button i clicked (eg. When I click on button 2 3, the button 3 3 will also change color).
Any ideas?
You can cast the Sender argument on the click handler to a Control and then use that to determine the clicked control's position. Then you can use that position to compute you adject controls and retrieve a reference to them.
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim ctrl As Control = TryCast(sender, Control)
If ctrl IsNot Nothing Then
Dim pos As TableLayoutPanelCellPosition = TableLayoutPanel1.GetCellPosition(ctrl)
If pos.Row < (TableLayoutPanel1.RowCount - 1) Then
Dim nextCtrl As Control = TableLayoutPanel1.GetControlFromPosition(pos.Column, pos.Row + 1)
If nextCtrl IsNot Nothing Then
' do something with nextCtrl
nextCtrl.BackColor = Color.Red
End If
End If
End If
End Sub
I have a datagridview as such:
With DataGridView1
.SelectionMode = DataGridViewSelectionMode.FullRowSelect
.ReadOnly = True
.AllowUserToAddRows = True
.MultiSelect = False
.EditMode = DataGridViewEditMode.EditProgrammatically
End With
When I do Ctrl + Click on last row my datagridview lost wanted functionality.
Sometimes select a row sometimes deselect and those little black triangle always jumps one row to lower.
I think this may be built in functionality for adding new data to grid.
Since I need my own Ctrl + Click on last row is there any chance to turn off those built in functionality so last row can behave as any other?
I am not sure about what you mean with a special functionality when Ctrl+Clicking on a cell. But if what you want is a code being triggered when a cell is clicked and Ctrl is pressed, you can rely on the CellMouseClick event:
Private Sub DataGridView1_CellMouseClick(sender As Object, e As System.Windows.Forms.DataGridViewCellMouseEventArgs) Handles DataGridView1.CellMouseClick
If (Control.ModifierKeys = Keys.Control) Then
MessageBox.Show("CTRL & Click")
End If
End Sub
What would be the syntax to check inside a visual basic form panel for checkboxes and find which are checked? I understand how I Could use a for loop and an if statement, but I'm confused as to the syntax to check for each checkbox. for example:
Dim i As Integer
For i = 1 To 10
'Here is where my code would go.
'I could have ten checkboxes named in sequence (cb1, cb2, etc),
'but how could I put i inside the name to test each checkbox?
Next
You need to loop through the Controls collection of the control that has the Checkbox's added to it. Each Control object has a Controls collection. I would prefer a For Each loop in this scenario so I get the Control right away without having to get it using the Controls index If your CheckBoxes are added to the Panel directly, the easiest way to do it would be..
For Each ctrl As var In panel.Controls
If TypeOf ctrl Is CheckBox AndAlso DirectCast(ctrl, CheckBox).IsChecked Then
'Do Something
End If
Next
I'm not very familiar with the VB.Net syntax, but in psudo-code:
ForEach CheckBox in ControlContainer
DoSomething
Next
If you have all of your CheckBox controls in a single container - e.g. a Panel - then the above code would iterate each control that is a CheckBox.
Try this :
Protected Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
If CheckBoxList1.Text = "" Then
do/display something
Exit Sub
Else
For Each item As ListItem In CheckBoxList1.Items
If item.Selected Then
do/display something
End If
Next
End If
End Sub
I have multiple textboxes which I want them to perform the same thing upon clicking them. By default I can use the handles textbox1.click for 1 single textbox as shown below but I am not sure how to do handle multiples of them. Of course I can write a handler for every single textbox but I have about 50 of them. I am sure there must be a more efficient way. Please advice. Thanks.
Sub TextBox1_click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.Click
If Button9.Text = "Make Changes" Then
If TextBox2.Text <> "" Then
Frm_Cine1.Show()
Frm_Cine1.chooseCine(ComboBox1.SelectedItem)
Else
MsgBox("Please check input!")
Exit Sub
End If
End If
End Sub
why don't you create a customizable textbox?
If Button9.Text = "Make Changes" Then
If TextBox2.Text <> "" Then
These two lines are going to be same for all those 50 buttons?
If yes, then I think you can assign same event handler to each of the button's click event.
Other way is, create one private method which takes one string as an argument and returns boolean value depending on whether your string is blank or not and call this method from all the 50 button's click event.
Thanks for all your advices, I am not sure if this is what you guys are suggesting but apparently it is how I wanted it to work:
Sub TextBoxs_click(ByVal sender As System.Object, ByVal e As System.EventArgs) _
Handles TextBox2.Click, TextBox3.Click, TextBox4.Click 'This part is disturbing if I have 50 textboxes...
'For Each obj As Control In Panel2.Controls
If sender.GetType.ToString = "System.Windows.Forms.TextBox" Then
Dim txtbox As TextBox = sender
textbox_verification(txtbox)
End If
'Next
End Sub
Sub textbox_verification(ByVal txtbox As TextBox)
If Button9.Text = "Make Changes" Then
If txtbox.Text <> "" Then
Frm_Cine1.Show()
Frm_Cine1.chooseCine(ComboBox1.SelectedItem, "FILE1-->This should be a variable")
Else
MsgBox("Please check timings input!")
Exit Sub
End If
End If
End Sub
If you indeed need to use the same click handler for multiple test boxes, you can use the AddHandler command to associate the click event of each test box with the handler routine, as shown:
AddHandler TextBoxX.Click AddressOf TextBox1_Click
You will need to add this statement to your program (maybe in the form load routine) once for each text box you want to handle. (Using the name of each text box in place of the "TextBoxX" in the above code.)