I have a GroupBox with multiple TextBox controls and I can check to see if any are empty just fine but I'm trying to make my program fill the first empty textbox it finds in the GroupBox.
Code:
Dim empty = From txt In grpbill.Controls.OfType(Of TextBox)()
Where txt.Text.Length = 0
If empty.Any Then
End If
Any ideas?
You're almost there. I'm unsure on how you define first but I've gone off the TabIndex property:
Dim firstEmptyTextBox As TextBox = (From txt In GroupBox1.Controls.OfType(Of TextBox)()
Where txt.Text.Length = 0
Order By txt.TabIndex Ascending).FirstOrDefault()
If firstEmptyTextBox IsNot Nothing Then
firstEmptyTextBox.Text = "Text"
End If
You can use the .FirstOrDefault() method:
Returns the first element of a sequence, or a default value if the sequence contains no elements.
In my example I have three TextBox controls. The first one has the text Not empty whilst the other two have nothing. When I run the code, this is my output:
Here another idea which will also work in cases where all TextBox controls in GroupBox are not empty.
Private Sub SetTextJForFirstEmptyTextBoxIfExists(text As String)
Dim emptyTextBoxes As IEnumerable(Of TextBox)
= grpbill.Controls.
OfType(Of TextBox)().
Where(Function(txtbox) txtbox.Text.Length = 0)
For Each emptyTextBox In emptyTextBoxes
emptyTextBox.Text = text
Exit Sub
Next
End Sub
Related
Sorry this is weird and silly question but I need a solution of this...
I have 30 textboxes named as Txt1,Txt2,Txt3,...,Txt30
I have to fill textbox as Txt1.text = 0 on button click..
Is there any way like On Button Click
Dim i as Integer
For i = 1 to 30 '----- Possible in string but don't know if possible in textboxes
Txt(i).text = 0
Next
Or I have to write all 30 lines like
Txt1.text = 0
...
Txt30.text = 0
I don't know how this question asked, maybe Question improper.
Thanx in Advance...
If the textboxes are all contained in Controls collection of the Form, then it is really easy to loop over them
For Each(t in Me.Controls.OfType(Of TextBox)())
t.Text = "0"
Of course the advantage of this approach is that you don't have to worry if you add other textboxes to your form. They will be found using the foreach loop without having a fixed top limit.
And, if not all of your textboxes should be included in the loop, then you can simply use the Tag property of the textboxes that you want to use. For example, if you set the Tag property to the string "Y", then you can change the foreach loop to find only the controls with the matching Tag property
For Each t in Me.Controls.OfType(Of TextBox)() _
.Where(Function(x) x.Tag = "Y")
t.Text = "0"
The two solutions above works well if all your textboxes are contained in the same container (Form, GroupBox or Panel), instead, if these textboxes are dispersed in different containers (some in a groupbox, others in a panel etc) then you can build a List(Of TextBox) variable filling it with the textboxes instances and use it when the need arise
Dim myTexts = New List(Of TextBox)() From { Txt1, Txt2, Txt3, ....}
And loop over this variable
You can do as Steve said, but if you have other textboxes that you don't want to edit then there is another way:
For i = 1 to 30
dim found = Me.Controls.Find("Txt" & i, True) '<- the True argument is for recursive search
If Not IsNothing(found) AndAlso found.Length > 0 Then
found(0).Text = "0"
End If
Next
If your textboxes are all in the same control, for example GroupBox, you can do GroupBox.Controls.Find saving CPU resources
I have a gridview that contais a textbox in row 0.
I am able to read the textbox with this two instructions:
Dim control As Control = gridview.Rows(0).FindControl("textbox")
Dim valueInTextbox As TextBox = CType(cntrol, TextBox)
My question is, how can I send data to textbox, for example sent the letter "A" to the textbox?. Any suggestion?
I am using this line to try to populate the textbox but my textbox disappear:
gridview.Rows(0).Cells(0).Text = "A"
Thanks.
You can set the text using the following lines:
Dim control As Control = gridview.Rows(0).FindControl("textbox")
If control IsNot Nothing Then
Dim valueInTextbox As TextBox = CType(cntrol, TextBox)
valueInTextbox.Text = "Some Text"
End If
So let's say I have 5 radio buttons on my form.
In my code, I want to check RadioButton3.
I have "RadioButton3" stored in a string variable (RadName)
I can already loop through the controls on the form. How do I go about checking (and actually having the radio button filled in), RadioButton3 when the loop gets to it?
For Each RadioButtn As Control In Me.gbWriteXML.Controls
If (TypeOf RadioButtn Is RadioButton) Then
---code here for checking the radio button---
End If
Next
The .gbWriteXML is a groupbox. Just to avoid any confusion. I was thinking something like:
If RadioButtn.Name = RadName Then
RadName.Checked = True (or .PerformClick for that button)
End If
How can I actually get the control associated with the RadName string, via the control's name?
I need this code to be able to take a radiobutton's name as string hardcoded or entered into the program at runtime, loop until it find the radiobutton with a matching name, then actually taking that radiobutton control, and checking it so it's filled in blue.
Don't loop. Just search for it with Controls.Find() like this:
Dim RadName As String = "RadioButton3"
Dim matches() As Control = Me.Controls.Find(RadName, True)
If matches.Length > 0 AndAlso TypeOf matches(0) Is RadioButton Then
Dim rb As RadioButton = DirectCast(matches(0), RadioButton)
rb.Checked = True
End If
I have a winform that has about 6 comboboxes and 3 textboxes. I also have a button that takes the values of aforementioned controls and inserts them into SQL. Is there a better way, than a bunch of nested if/then statements, to verify that the controls all have values before inserting the data? This gets ugly very fast. I have tried googling this answer, but I get too many ASPx answers. I will entertain any ideas you may have. I am just trying to find a better way to do this. Thanks for any help.
I think its not too hard.
This code shows error message about the first empty textbox or combobox. But you can easily modify to show error message for all empty comboboxes and textboxes if required.
Private Function ValidateMyControls() As Boolean
Dim allComboBoxes() As ComboBox = {ComboBox1, ComboBox2, ComboBox3} ' add all your comboboxes here
Dim allTextBoxes() As TextBox = {TextBox1, TextBox2, TextBox3} ' add all your textboxes here
Dim emptyTB As TextBox = allTextBoxes.Where(Function(f) f.Text = "").FirstOrDefault
Dim emptyCB As ComboBox = allComboBoxes.Where(Function(f) f.SelectedIndex = -1).FirstOrDefault
If emptyTB IsNot Nothing Then
MessageBox.Show("Please fill value in " & emptyTB.Name)
Return False
ElseIf emptyCB IsNot Nothing Then
MessageBox.Show("Please select a value in dropdown " & emptyCB.Name)
Return False
Else
' All set to go!
Return True
End If
End Function
I have multiple TextBox controls Monday that will hold a value. I want to be able to add up all of the Monday textboxes and store that value as monTotal. I am getting an error message that says string cannot be converted to integer.
For i As Integer = 1 To rowCount Step 1
Dim var As Object
var = "txtMonday" & i & ".Text"
monTotal = monTotal + CInt(var)
Next
The way you are attempting to obtain a reference to the text boxes is not idiomatic of VisualBasic .NET.
var = "txtMonday" & i & ".Text" ' this is not a way to obtain a reference to the text box's text
While it would be possible to accomplish something like that using reflection, you'd be much better off refactoring your code to use an array of text boxes.
Since you are probably using Windows Forms you could perhaps implement logic to find the text box control you are interested in on the form using something like this:
' assuming container is the control that contains the text boxes
For Each ctrl In container.Controls
If (ctrl.GetType() Is GetType(TextBox)) Then
If ctrl.Name.StartsWith("txtMonday") Then
Dim txt As TextBox = CType(ctrl, TextBox)
monTotal = monTotal + CInt(txt.Text)
End If
End If
Next
The example above assumes that all the txtMonday.. text boxes are placed inside a control named container. That could be the form itself, or some other panel or table.
If all the textboxes live on the form and there are none being used for other text work you could use this. You could place all the textboxes that contain values your looking for in a separate container and get them like below, but use that control collection.
Dim amount As Double = 0
For Each tb As Textbox In Me.Controls.OfType(Of Textbox)()
amount += Convert.ToDouble(tb.Text)
Next
Dim monTotal as double=0
For Each ctrl As Control In Me.Controls
If TypeOf ctrl Is TextBox AndAlso ctrl.Name.StartsWith("txtMonday") Then
monTotal = monTotal + val(ctrl.Text)
End If
Next