I'm able to use the code below to check whether or not a user inputs a string in a datagridview cell. If the user inputs a string a message pops up to tell them "only numeric entries are allowed". This is exactly what I want my code to do. However if I try to use this code in a column of data populated with numbers I get an error message that says "error happened, parsing commit". If anyone is able to figure out what the issue is here I would greatly appreciate it!
If (e.ColumnIndex = 3) Then 'checking numeric value for column 3 only
Dim value As String = DataGridView1.Rows(e.RowIndex).Cells(e.ColumnIndex).Value
For Each c As Char In value
If Not Char.IsDigit(c) Then
MessageBox.Show("Please Enter numeric Value")
DataGridView1.Rows(e.RowIndex).Cells(e.ColumnIndex).Value = 3 'This will set the defaultvalue of the datagrid cell in question to the value of "3"
Exit Sub
End If
Next
End If
This solution not only checks for non-integer values it also works for every column populated with numbers for the entire datagridview. Also if the user inputs a non-integer if will supply a default value for the datagridviewcell, this default value is the previous number.
Private Sub DataGridView1_DataError(ByVal sender As Object, _
ByVal e As DataGridViewDataErrorEventArgs) _
Handles DataGridView1.DataError
If StrComp(e.Exception.Message, "Input string was not in a correct format.") = 0 Then
MessageBox.Show("Please Enter a numeric Value")
'This will change the number back to original
DataGridView1.Rows(e.RowIndex).Cells(e.ColumnIndex).Value = " "
End If
End Sub
Do this in cellvalidating event ...
If (e.ColumnIndex = 3) Then 'checking numeric value for column 3 only
If Not Isnumeric(e.Formatted.Value) Then
MessageBox.Show("Please Enter numeric Value")
DataGridView1.Rows(e.RowIndex).Cells(e.ColumnIndex).Value = 3 'This will set the defaultvalue of the datagrid cell in question to the value of "3"
Exit Sub
End If
End If
Related
I'm using VB.NET for a small project. I have a DataGridView with some rows and columns.
I want to send amounts inside a specific row & column. For this purpose I'm using a ComboBox to select the receiver, but I cant manage to select the specific row & column for the amount.
Here is a photo of the form:
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I managed to add the receivers inside the ComboBox and to add an amount, but in all rows.
This is code (it auto generates the rows for now).
Public Class Form1
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim rowId As Integer = Me.DataGridView1.Rows.Add()
Dim row As DataGridViewRow = Me.DataGridView1.Rows(rowId)
row.Cells("Column1").Value = "UNITED BANK"
row.Cells("Column2").Value = "1000"
row.Cells("Column3").Value = "ExampleInfo"
Dim rowId2 As Integer = Me.DataGridView1.Rows.Add()
Dim row2 As DataGridViewRow = Me.DataGridView1.Rows(rowId2)
row2.Cells("Column1").Value = "FREE BANK"
row2.Cells("Column2").Value = "2000"
row2.Cells("Column3").Value = "ExampleInfo"
Dim bolAdd As Boolean = False
Dim strValue As String
For Each myRow As DataGridViewRow In Me.DataGridView1.Rows
bolAdd = True
strValue = myRow.Cells("Column1").Value
For Each myItem As String In Me.ComboBox1.Items
If myItem = strValue Then bolAdd = False
Next
If bolAdd AndAlso Not (strValue Is Nothing) Then Me.ComboBox1.Items.Add(strValue)
Next
If Me.ComboBox1.SelectedIndex = -1 Then
Me.ComboBox1.SelectedIndex = 0
End If
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
For Each rowX As DataGridViewRow In Me.DataGridView1.Rows
rowX.Cells(1).Value = Val(rowX.Cells(1).Value) + Val(TextBox1.Text)
Next
End Sub
End Class
With this code, I'm able to add an amount, but to all rows.
I want to add an amount only to the row I selected in the ComboBox.
Your current code in the Button1_Click event is adding the amount from the text box to ALL the rows in the grid regardless of “what” value is selected in the combo box.
From what you describe, you want the amount from the text box to be added to rows that “match” the value in the combo box. The current code is never checking this, so the value from the text box is added to all the rows in the grid.
Therefore, the code needs to check to see if the value in Column1 "Receiver" “matches” the value in the combo box. If it DOES match, then add the value from the text box to the current value in Column2 "USD."
It is unclear if there may be more rows in the grid that have the same Column1 "Receiver" value and if you want to update those values also. I am assuming that there will only be ONE row in the grid that “matches” the value in the combo box. Therefore, once we find this value and add the amount, then we are done and the code will return without looping through the rest of the rows in the grid.
So is what you need to do is alter the code in the button click event to do this checking as described above.
There are a lot of checks we need to make. We need to check that the combo box has a value to compare to. Also, before we check ANY cell value, we need to make sure the cells value is not null BEFORE we try and call the cell's Value ToString method.
In addition, the cell MAY have a value, however, it may not be a number, so we have to check and make sure the value in the cell is an actual number and the same would apply to the text box.
So, walking through the code below would go something like…
If (Int32.TryParse(TextBox1.Text, addedValue)) … checks to see if
the text box amount is a valid number.
If (Not String.IsNullOrEmpty(targetComboValue)) … checks to make
sure the combo box value is not empty.
Then we start the loop through all the rows in the grid.
If (Not rowX.IsNewRow) … checks to see if the row is the “new” row
which we will ignore this “new” row.
If (rowX.Cells("Column1").Value IsNot Nothing) … checks to make
sure the “Receiver” cell is not null
If (rowX.Cells("Column1").Value.ToString() = targetComboValue) …
checks to see if the “Receiver” cells value matches the value in the
combo box.
If (rowX.Cells("Column2").Value IsNot Nothing) … check to make sure
the “USD” cell is not null.
And Finally,…
If (Int32.TryParse(rowX.Cells("Column2").Value.ToString(), currentValue)) … check to see if the value in the “USD” cell is a valid number.
If all these checks succeed then add the value from the text box to the current value in the “USD” cell.
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim targetComboValue = ComboBox1.SelectedItem
Dim addedValue As Int32
Dim currentValue As Int32
If (Int32.TryParse(TextBox1.Text, addedValue)) Then
If (Not String.IsNullOrEmpty(targetComboValue)) Then
For Each rowX As DataGridViewRow In Me.DataGridView1.Rows
If (Not rowX.IsNewRow) Then
If (rowX.Cells("Column1").Value IsNot Nothing) Then
If (rowX.Cells("Column1").Value.ToString() = targetComboValue) Then
If (rowX.Cells("Column2").Value IsNot Nothing) Then
If (Int32.TryParse(rowX.Cells("Column2").Value.ToString(), currentValue)) Then
rowX.Cells("Column2").Value = currentValue + addedValue
Return
End If
End If
End If
End If
End If
Next
End If
End If
End Sub
I hope this makes sense.
You can edit the desired row just by using a syntax as follow:
Me.DataGridView1.Rows(1).Cells(2).Value = "your string"
So if you want to select corresponding to your combo index :
Dim myId As Integer = Me.ComboBox1.SelectedIndex
Me.DataGridView1.Rows(myId).Cells(2).Value = "your string"
But this assuming that the count of combo and DataGridView are same.
If not you should think about to add an id Column in your DataGridView ...
If you mean something else please explain, I will edit.
I am new to Visual Basic programming. I'm using a multi-line textbox to accept only numerical inputs from the users.
I need to remove any white space before adding it to my listbox. For example like ( 8) becomes 8 when added into the listbox and I shouldn't let the user proceed if there is no input or only whitespace as an input. Thank you in advance :)
For i As Integer = 0 To Val(TxtInput.Lines.Count) - 1
If TxtInput.Lines(i) = "" Then 'Ignores newline inputs
'Placeholder Comment
ElseIf IsNumeric(TxtInput.Lines(i)) Then 'Tests for Numbers
Temp.LbInput.Items.Add(TxtInput.Lines(i))
Temp.Show()
Else
MsgBox("Your input must only be in numbers, check for invalid inputs!", 1, "Error")
Temp.LbInput.Items.Clear()
Return
End If
Next
This is the kind of thing linq-to-objects was made for:
Dim result = TxtInput.Lines.
Select(Function(line) line.Trim).
Where(Function(line) Not String.IsNullOrWhitespace(line) AndAlso IsNumeric(line)).
Select(Function(line) Val(line))
You can also do this:
Dim lines = TxtInput.Lines.Select(Function(line) line.Trim)
If lines.Any(Function(line) Not IsNumeric(line)) Then
MsgBox("Your input must only be in numbers, check for invalid inputs!", 1, "Error")
Exit Sub
Else
Dim result = lines.Where(Function(line) Not String.IsNullOrWhitespace(line)).
Select(Function(line) Val(line))
'Do more with "result" here
End If
Just store the trimmed line into a variable
For i As Integer = 0 To TxtInput.Lines.Count - 1
Dim line As String = TxtInput.Lines(i).Trim() '<======================
If line = "" Then 'Ignores newline inputs
'Placeholder Comment
ElseIf IsNumeric(line) Then 'Tests for Numbers
Temp.LbInput.Items.Add(line)
Temp.Show()
Else
MsgBox("Your input must only be in numbers, check for invalid inputs!", 1, "Error")
Temp.LbInput.Items.Clear()
Return
End If
Next
Also, TxtInput.Lines.Count is an Integer already. No need to convert with Val, which, by the way, converts it into a Double.
Note that you can add items of any type to the ListBox, so you could as well convert the line into the desired type. I don't know if you need Integer or Double. Let's assume that you only want integer numbers. then you can change the code to
If TxtInput.Lines.Count = 0 Then
MsgBox("You have not entered anything. Please enter a number!", 1, "Error")
Else
For i As Integer = 0 To TxtInput.Lines.Count - 1
Dim line As String = TxtInput.Lines(i).Trim()
Dim number As Integer
If line = "" Then
MsgBox("Your input is empty. Please enter some numbers!", 1, "Error")
ElseIf Integer.TryParse(line, number) Then 'Tests for Numbers
Temp.LbInput.Items.Add(number)
Temp.Show()
Else
MsgBox("Please enter only valid numbers!", 1, "Error")
Temp.LbInput.Items.Clear()
Return
End If
Next
End If
(Code changed according to your comments.)
If you want doubles, just declare number as Double and convert with Double.TryParse(line, number).
This code is from a subroutine that checks if a text box entry fits the criteria specified (an integer between 1 and 100).
The first IF statement should check if it is not a numerical entry. If it is not numerical then the contents of the text box should be set blank so that a number can be entered.
The second IF statement should check if the number is larger than 100. If it is then the contents of the text box should be set blank so that an appropriate number can be entered.
The Third IF statement should check if the number is smaller than 1. If it is then the contents of the text box should be set blank so that an appropriate number can be entered.
Finally the contents of the box should be set as the variable.
I initially programmed the first IF statement on its own and it worked. But upon adding the others my program would crash when I typed anything into the text box and the error was as stated in my title. I have looked at multiple solutions and have found nothing for almost 2 days that fixed the problem.
Any suggestions would be appreciated.
Public Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles NumQTextBoxInput.TextChanged
'Check if input is numeric
If Not IsNumeric(NumQTextBoxInput.Text) Then NumQTextBoxInput.Text = ""
If (NumQTextBoxInput.Text > 100) Then
NumQTextBoxInput.Text = ""
End If
If (NumQTextBoxInput.Text < 1) Then
NumQTextBoxInput.Text = ""
End If
ArchwayComputingExamCreator.GlobalVariables.NumOfQuestions = NumQTextBoxInput.Text
'Setting the variable to the contense
End Sub
You should always use the appropriate parse function when accepting text for numbers.
Public Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles NumQTextBoxInput.TextChanged
Dim Value as integer
If Not Integer.TryParse(NumQTextBoxInput.text, Value) OrElse Value < 1 OrElse Value > 100 Then NumQTextBoxInput.Text = ""
... no idea if the archway bit is really what you wanted so left that out ....
End Sub
In this operation:
If Not IsNumeric(NumQTextBoxInput.Text) Then NumQTextBoxInput.Text = ""
Any time the input is not numeric, you set it to a value which is still not numeric. So any numeric comparison will fail:
If (NumQTextBoxInput.Text > 100)
Maybe you meant to set the value to some numeric default?:
If Not IsNumeric(NumQTextBoxInput.Text) Then NumQTextBoxInput.Text = "0"
Or just exit the method entirely when it's not numeric?:
If Not IsNumeric(NumQTextBoxInput.Text) Then
NumQTextBoxInput.Text = ""
Return
End If
Or perhaps something else? However you modify your logic, the point is that you can't perform numeric comparisons on non-numeric strings.
I'm trying to allow only alphanumeric input in my datagridview column. Is there a way to allow alphanumeric input and also prevent the user from entering negative numbers or leaving the cell blank? If anyone has any suggestions or answers I would greatly appreciate it! :) Here is my code below. I already have the negative and blank cell validation working, but its not allowing me to input non-numeric input.
If (e.ColumnIndex = 0) Then 'checking value for column 1 only
Dim cellData = DataGridView1.Rows(e.RowIndex).Cells(e.ColumnIndex).Value
If cellData Is Nothing OrElse IsDBNull(cellData) OrElse cellData.ToString = String.Empty Then ' This will prevent any blank cells
MessageBox.Show("Name Cannot Be Empty")
DataGridView1.Rows(e.RowIndex).Cells(e.ColumnIndex).Value = "Object" ' This is a default value that I want to supply after the message box
ElseIf cellData < 0 Then
MessageBox.Show("Negative Numbers Not Allowed") 'This prevents negative numbers
DataGridView1.Rows(e.RowIndex).Cells(e.ColumnIndex).Value = "Object"
Exit Sub ' Again this a default value I want supplied back to the datagridivewcell
End If
End If
So my code works, except when I enter any type of non-numeric character the program stops and exits.
Try using TryParse like this:
If (e.ColumnIndex = 0) Then 'checking value for column 1 only
Dim cellValue As Integer
If (Int32.TryParse(DataGridView1.Rows(e.RowIndex).Cells(e.ColumnIndex).Value, cellValue)) Then
If cellValue < 0 Then
MessageBox.Show("Negative Numbers Not Allowed") 'This prevents negative numbers
DataGridView1.Rows(e.RowIndex).Cells(e.ColumnIndex).Value = "Object"
Exit Sub ' Again this a default value I want supplied back to the datagridivewcell
End If
Else
Dim testValue As String = DataGridView1.Rows(e.RowIndex).Cells(e.ColumnIndex).Value
If (String.IsNullOrEmpty(testValue)) Then
MessageBox.Show("Name Cannot Be Empty")
DataGridView1.Rows(e.RowIndex).Cells(e.ColumnIndex).Value = "Object" ' This is a default value that I want to supply after the message box
End If
End If
End If
NOTE: I tried using concat() method, join method and even tried to
insert just text(which turned out editable) but none of them worked as
I wanted. I was thinking if substring method will work but I only have
basic idea of how substring works. I want the letter "N" to be
inserted into the text box when form loads and when the user enters
4digits(OrderNo2.text) which should be joined so that it can be saved
together when I clicked on save button.
Please help guys. Thanks
Private Sub btnAddOrder_Click(ByVal sender As System.Object, ByVal e
As System.EventArgs) Handles btnAddOrder.Click
isNewRow = True
Dim newRow As DataRow = dsOrders.Tables("Orders").NewRow
Try
If txtOrderNo2.Text.Length = 5 Then
newRow.Item("OrderNo") = txtOrderNo2.Text
If cbo_Product.SelectedIndex <> -1 Then
newRow.Item("Product") = cbo_Product.Text
newRow.Item("Price") = txtPrice2.Text
If txtQuantity.Text <> "" Then
newRow.Item("Quantity") = txtQuantity.Text
newRow.Item("CustomerNo") = txtCustomerNo2.Text
dsOrders.Tables("Orders").Rows.Add(newRow)
'determine row index of new row
rowIndex = dsOrders.Tables("Orders").Rows.Count - 1
'save changes back to the database
daOrders.Update(dsOrders, "Orders")
Else
MessageBox.Show("Please enter the quantity", "Missing Quantity", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
End If
Else
MessageBox.Show("Please choose the product", "Missing Price", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
End If
Else
MessageBox.Show("Order Number must be 5 digits long!", "Missing Order Number", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
End If
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
Used a MaskedTextBox instead of a regular TextBox. You can then set the Mask property to "N0000", which will only allow the user to enter 4 digits following the 'N', and will not let the user edit the 'N'. The Text property will give you the displayed text, including the 'N'.
Try just allowing only digits in the textbox with a max lenght of 4.
Then if the user clicks on the submit button just get the value of the input and place the N infront of it.
You will always have a length of 4 + your character("N") is 5.
That way you should be able to fix it.
You can also try using a regex. to see if it contains the N and numbers from 0-9.
only if it starts with the character N followed by 4 numberic characters it will be a valid input.
This would be your regex then.
^(N?[0-9]{4})$
Hope this can be of any use to you