I m new to vb.net & I have a problem that whenever user enters an alphabet he/she will receive message that only numbers are allowed. For this code.... Please help me. I shall be very thankful to you.
Public Class Form1
Private Sub DataGridView1_EditingControlShowing(sender As Object, e As DataGridViewEditingControlShowingEventArgs) Handles DataGridView1.EditingControlShowing
If DataGridView1.CurrentCell.ColumnIndex = 0 Then
Dim combo As ComboBox = CType(e.Control, ComboBox)
If (combo IsNot Nothing) Then
RemoveHandler combo.SelectionChangeCommitted, New EventHandler(AddressOf ComboBox_SelectionChangeCommitted)
AddHandler combo.SelectionChangeCommitted, New EventHandler(AddressOf ComboBox_SelectionChangeCommitted)
End If
End If
End Sub
Private Sub ComboBox_SelectionChangeCommitted(ByVal sender As System.Object, ByVal e As System.EventArgs)
Dim combo As ComboBox = CType(sender, ComboBox)
If combo.SelectedItem = "Item1" Then
DataGridView1.CurrentRow.Cells(1).Value = "KG"
DataGridView1.CurrentRow.Cells(3).Value = "100"
DataGridView1.CurrentRow.Cells(2).Value = "Raw Material"
ElseIf combo.SelectedItem = "Item2" Then
DataGridView1.CurrentRow.Cells(1).Value = "Liter"
DataGridView1.CurrentRow.Cells(3).Value = "47"
DataGridView1.CurrentRow.Cells(2).Value = "Raw Material"
ElseIf combo.SelectedItem = "Item3" Then
DataGridView1.CurrentRow.Cells(1).Value = "Pound"
DataGridView1.CurrentRow.Cells(3).Value = "54"
DataGridView1.CurrentRow.Cells(2).Value = "Raw Material"
End If
End Sub
Private Sub Mul_Button_Click(sender As Object, e As EventArgs) Handles Mul_Button.Click
Dim s As Int16 = Convert.ToInt16(DataGridView1.CurrentRow.Cells(3).Value)
Dim s1 As Int16 = Convert.ToInt16(DataGridView1.CurrentRow.Cells(4).Value)
DataGridView1.CurrentRow.Cells(5).Value = s * s1
End Sub
Private Sub DataGridView1_CellValidated(sender As Object, e As EventArgs) Handles DataGridView1.CellValidated
Dim s As Int16 = Convert.ToInt16(DataGridView1.CurrentRow.Cells(3).Value)
Dim s1 As Int16 = Convert.ToInt16(DataGridView1.CurrentRow.Cells(4).Value)
DataGridView1.CurrentRow.Cells(5).Value = s * s1
If DataGridView1.RowCount > 0 Then
Dim sum As Integer
For index As Integer = 0 To DataGridView1.RowCount - 1
sum += Convert.ToInt32(DataGridView1.Rows(index).Cells(5).Value)
Next
TextBox1.Text = sum
End If
End Sub
Private Sub Add_Button_Click(sender As Object, e As EventArgs) Handles Add_Button.Click
If DataGridView1.RowCount > 0 Then
Dim sum As Integer
For index As Integer = 0 To DataGridView1.RowCount - 1
sum += Convert.ToInt32(DataGridView1.Rows(index).Cells(5).Value)
Next
TextBox1.Text = sum
End If
End Sub
End Class
Either wrap your code that has Convert.ToInt16() calls in them with Try/Catch blocks, or convert them to the Int16.TryParse() approach instead.
For example, this line:
Dim s As Int16 = Convert.ToInt16(DataGridView1.CurrentRow.Cells(3).Value)
Could become:
Dim s As Int16
Dim strValue As String = DataGridView1.CurrentRow.Cells(3).Value
If Int16.TryParse(strValue, s) Then
' ... do something with "s" in here ...
' ... continue with code...
Else
MessageBox.Show(strValue, "Invalid Value")
End If
Related
I'm new at visual basic programming and everything was fine until our topic shifted to arrays. I tried to understand it's code using Java. (Example: method are called functions.. .)
My prof has given us an exercise to create a Quiz program that asks the user more than 5 questions (in textbox) with choices (in buttons) and computes the score at the end (All just in one form). If the user click an a button it will tell if it's right or wrong and then proceed to change the question along with the choices.
*Required: - After the user finish the quiz the score will be displayed and there should be a restart button and all the question will be asked again randomly no pattern. - Try to make functions.
I tried searching the web since yesterday and I still have made no progress at my code.
Public Class Form1
Dim questions(5) As String
Dim answers(5) As String
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'Method/Function for loading the Q&A
loadQsAndAs()
End Sub
Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click
Me.Close()
End Sub
Private Sub loadQsAndAs()
'Questions
questions(0) = "What is 1 + 1?"
questions(1) = "Who is the first man to walk on the Moon?"
questions(2) = "What is the name of the main character in the movie: Yes Man! (2007)"
questions(3) = "If I gave you three apples and you ate two, how many is left?"
questions(4) = "What do you want in your final grade?"
questions(5) = "What is the name of the thing(s) that you use whenever you eat?"
'Answers
answers(0) = "2"
answers(1) = "Neil Armstrong"
answers(2) = "Jim Carrey"
answers(3) = "1"
answers(4) = "A 4.0"
answers(5) = "A Spoon and Fork"
TextBox1.Text = setTheQuestion()
Button1.Text = setTheAnswer1()
Button2.Text = setTheAnswer2()
Button3.Text = setTheAnswer3()
Button4.Text = setTheAnswer4()
End Sub
Private Function setTheQuestion() As String
Dim randomValue As New Random
Dim randomQ As String = ""
Dim i As Integer
Dim index As Integer
For i = 0 To 0
index = randomValue.Next(0, questions.Length)
randomQ &= questions(index)
Next
Return randomQ
End Function
Private Function setTheAnswer1() As String
Dim randomValue As New Random
Dim randomAns As String = ""
Dim i As Integer
Dim index As Integer
For i = 0 To 0
index = randomValue.Next(0, answers.Length)
randomAns &= answers(index)
Next
Return randomAns
End Function
Private Function setTheAnswer2() As String
Dim randomValue As New Random
Dim randomAns As String = ""
Dim i As Integer
Dim index As Integer
For i = 0 To 0
index = randomValue.Next(1, answers.Length)
randomAns &= answers(index)
Next
Return randomAns
End Function
Private Function setTheAnswer3() As String
Dim randomValue As New Random
Dim randomAns As String = ""
Dim i As Integer
Dim index As Integer
For i = 0 To 0
index = randomValue.Next(2, answers.Length)
randomAns &= answers(index)
Next
Return randomAns
End Function
Private Function setTheAnswer4() As String
Dim randomValue As New Random
Dim randomAns As String = ""
Dim i As Integer
Dim index As Integer
For i = 0 To 0
index = randomValue.Next(3, answers.Length)
randomAns &= answers(index)
Next
Return randomAns
End Function
Private Sub Button6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button6.Click
loadQsAndAs()
End Sub
End Class
Public Class Form1
Dim questions As New ArrayList
Dim answers As New ArrayList
Dim dtQAMain As New DataTable
Dim questionsCopy As New ArrayList
Dim alAnsButton As New ArrayList 'arraylist to store all answer button.
Dim totalScore As Integer
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs)
Handles MyBase.Load
'Method/Function for loading the Q&A
alAnsButton.Add(Button1)
alAnsButton.Add(Button2)
alAnsButton.Add(Button3)
alAnsButton.Add(Button4)
loaddtQA()
loadQsAndAs()
End Sub
Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
Handles Button5.Click
Me.Close()
End Sub
Private Sub loaddtQA()
dtQAMain = New DataTable
dtQAMain.Columns.Add("Q")
dtQAMain.Columns.Add("A")
For i = 0 To 5
questions.Add("")
answers.Add("")
Next
'Questions
questions(0) = "What is 1 + 1?"
questions(1) = "Who is the first man to walk on the Moon?"
questions(2) = "What is the name of the main character in the movie: Yes Man!(2007)"
questions(3) = "If I gave you three apples and you ate two, how many is left?"
questions(4) = "What do you want in your final grade?"
questions(5) = "What is the name of the thing(s) that you use whenever you eat?"
'Answers
answers(0) = "2"
answers(1) = "Neil Armstrong"
answers(2) = "Jim Carrey"
answers(3) = "1"
answers(4) = "A 4.0"
answers(5) = "A Spoon and Fork"
For i = 0 To questions.Count - 1
dtQAMain.Rows.Add(questions(i), answers(i)) 'assign QA in table for scoring purpose later
Next
End Sub
Private Sub loadQsAndAs()
Label1.Visible = False
For i = 0 To alAnsButton.Count - 1
alAnsButton(i).visible = True
Next
questionsCopy = New ArrayList
questionsCopy = questions.Clone 'close a copy so we dont effect the actual question copy when randomize and eliminate asked question from arraylist
TextBox1.Text = setTheQuestion()
setTheAnswer()
End Sub
Private Function setTheQuestion() As String
Dim randomValue As New Random
Dim randomQ As String = ""
Dim index As Integer
If questionsCopy.Count <> 0 Then
index = randomValue.Next(0, questionsCopy.Count - 1)
randomQ = questionsCopy(index)
questionsCopy.RemoveAt(index) 'asked question will be remove.
Else ' questions are finished, show the mark
ShowMark()
End If
Return randomQ
End Function
Private Sub setTheAnswer() 'randonmize the answer and assign to button
If TextBox1.Text = "" Then Exit Sub ' if question finish exit sub
Dim randomValue As New Random
Dim NewIndex As Integer
Dim temp As String
Dim answersCopy As ArrayList = answers.Clone
For n = answersCopy.Count - 1 To 0 Step -1
NewIndex = randomValue.Next(0, n + 1)
' Swap them.
temp = answersCopy(n)
answersCopy(n) = answersCopy(NewIndex)
answersCopy(NewIndex) = temp
Next
Dim AnswerRowCheck As Integer = questions.IndexOf(TextBox1.Text)
Dim ActualAnswer As String = dtQAMain.Rows(AnswerRowCheck).Item("A") 'check actual answer
Dim totalRemove As Integer = 0
For i = answersCopy.Count - 1 To 0 Step -1
If totalRemove = 2 Then Exit For
If answersCopy(i) <> dtQAMain.Rows(AnswerRowCheck).Item("A") Then
answersCopy.RemoveAt(i)
totalRemove += 1
End If
Next 'remove 2 of the selection,since only 4 button for answer selection and should not take out the actual answer
For i = 0 To alAnsButton.Count - 1
alAnsButton(i).text = answersCopy(i)
Next
End Sub
Private Sub ShowMark()
For i = 0 To alAnsButton.Count - 1
alAnsButton(i).text = "" 'clear the text, no more input receive from user.
Next
Label1.Visible = True
Label1.Text = totalScore & " out of 6 are correct."
End Sub
Private Sub Button6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button6.Click
totalScore = 0
loadQsAndAs() 'refresh question
End Sub
Private Sub Button4_MouseClick(sender As Object, e As MouseEventArgs) Handles Button4.MouseClick, Button3.MouseClick, Button2.MouseClick, Button1.MouseClick
If sender.text = "" Then Exit Sub
Dim AnswerRowCheck As Integer = questions.IndexOf(TextBox1.Text) 'search question number
If dtQAMain.Rows(AnswerRowCheck).Item("A") = sender.text Then 'checking answer
totalScore += 1
End If
TextBox1.Text = setTheQuestion() 'next question
setTheAnswer()
End Sub
End Class
The code had cover most of the necessary comment which include the idea and how it work. Random() and arraylist are the key for this program to function, just pay more attention on it. Good luck.
How about trying this?
Public Class Form1
Dim questions(5) As String
Dim answers(5) As String
Private Sub loadQsAndAs()
'Questions
questions(0) = "What is 1 + 1?"
questions(1) = "Who is the first man to walk on the Moon?"
questions(2) = "What is the name of the main character in the movie: Yes Man! (2007)"
questions(3) = "If I gave you three apples and you ate two, how many is left?"
questions(4) = "What do you want in your final grade?"
questions(5) = "What is the name of the thing(s) that you use whenever you eat?"
'Answers
answers(0) = "2"
answers(1) = "Neil Armstrong"
answers(2) = "Jim Carrey"
answers(3) = "1"
answers(4) = "A 4.0"
answers(5) = "A Spoon and Fork"
Dim random As New Random
Dim indices = { 0, 1, 2, 3, 4, 5 }.OrderBy(Function (n) random.Next()).ToArray()
Dim question = random.Next(questions.Length - 1)
TextBox1.Text = questions(indices(question))
Button1.Text = answers(indices(0))
Button2.Text = answers(indices(1))
Button3.Text = answers(indices(2))
Button4.Text = answers(indices(3))
End Sub
End Class
That's it. Nice and simple. The key trick is creating a randomize indices array to do the lookups into the questions and answers arrays.
Private Dim rnd As Integer
Private Function setTheQuestion() As String
rnd = (CInt(Math.Ceiling(Rnd() * questions.Length)) + 1)
Return questions(rnd)
End Function
Private Function setTheAnswer1() As String
Return answers(rnd)
End Function
I am creating a student test score application which shows student averages, class averages (I haven't done this part yet) and can search for a particular student which shows up in the text boxes.
Can someone please tell me how to write the test scores and name of student entered into the text boxes to an Excel CSV file?
Also the save button keeps clearing all the enteries to the CSV file when I click on it. If anyone could tell me whats going on there, that would be great.
Imports System.IO
Public Class Form1
Structure Students
Dim StudentName As String
Dim Test1 As Double
Dim Test2 As Double
Dim Test3 As Double
Dim Test4 As Double
Dim Test5 As Double
End Structure
Dim StudentCounter As Integer = 0
Dim MyStudentArray(StudentCounter) As Students
Private Sub LoadDataFromFileToArray()
Dim TextFile As New System.IO.StreamReader(“..\..\StudentDataFile.csv”)
Dim strStudentData As String
strStudentData = TextFile.ReadLine()
Do Until strStudentData Is Nothing
lstAllStudentData.Items.Add(strStudentData)
WriteToArray(strStudentData)
strStudentData = TextFile.ReadLine()
Loop
TextFile.Close()
End Sub
Private Sub WriteToArray(ByVal CurrentLine)
Dim Values() As String = Split(CurrentLine, ",")
ReDim Preserve MyStudentArray(StudentCounter)
MyStudentArray(StudentCounter).StudentName = Values(0)
MyStudentArray(StudentCounter).Test1 = (Values(1))
MyStudentArray(StudentCounter).Test2 = (Values(2))
MyStudentArray(StudentCounter).Test3 = (Values(3))
MyStudentArray(StudentCounter).Test4 = (Values(4))
MyStudentArray(StudentCounter).Test5 = (Values(5))
StudentCounter += 1
End Sub
Private Sub btnAddStudent_Click(sender As Object, e As EventArgs) Handles btnAddStudent.Click
ReDim Preserve MyStudentArray(StudentCounter)
MyStudentArray(StudentCounter).Test1 = CDbl(txtTest1.Text)
MyStudentArray(StudentCounter).Test2 = CDbl(txtTest1.Text)
MyStudentArray(StudentCounter).Test3 = CDbl(txtTest1.Text)
MyStudentArray(StudentCounter).Test4 = CDbl(txtTest1.Text)
MyStudentArray(StudentCounter).Test5 = CDbl(txtTest1.Text)
MyStudentArray(StudentCounter).StudentName = (txtStudentName.Text)
StudentCounter += 1
End Sub
Private Sub CalculateIndividual()
Dim AverageScore As Double = 0
Dim Test1 As Double = CDbl(txtTest1.Text)
Dim Test2 As Double = CDbl(txtTest2.Text)
Dim Test3 As Double = CDbl(txtTest3.Text)
Dim Test4 As Double = CDbl(txtTest4.Text)
Dim Test5 As Double = CDbl(txtTest5.Text)
Dim AverageGrade As String
AverageScore = (Test1 + Test2 + Test3 + Test4 + Test5) / 5
lblScoreOutput.Text = AverageScore
lblScoreOutput.Visible = True
Select Case AverageScore
Case > 90
AverageGrade = "A+"
Case 80 To 90
AverageGrade = "A"
Case 70 To 80
AverageGrade = "B"
Case 60 To 70
AverageGrade = "C"
Case 50 To 60
AverageGrade = "D"
Case 35 To 50
AverageGrade = "E"
Case Else
AverageGrade = "UG"
End Select
lblLetterOutput.Text = AverageGrade
lblLetterOutput.Visible = True
End Sub
Private Sub Form_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
Dim response As MsgBoxResult
response = MsgBox("Do you want to close Student Calculator", MsgBoxStyle.Question + MsgBoxStyle.YesNo, "Confirm")
If response = MsgBoxResult.Yes Then
Me.Dispose()
ElseIf response = MsgBoxResult.No Then
e.Cancel = True
Exit Sub
End If
End Sub
Private Sub btnExit_Click(sender As Object, e As EventArgs) Handles btnExit.Click
Dim response As MsgBoxResult
response = MsgBox("Do you want to close Student Calculator?", MsgBoxStyle.Question + MsgBoxStyle.YesNo, "Confirm")
If response = MsgBoxResult.Yes Then
Me.Dispose()
ElseIf response = MsgBoxResult.No Then
Exit Sub
End If
End Sub
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
lstAllStudentData.Items.Clear()
LoadDataFromFileToArray()
lstAllStudentData.Items.Clear()
LoadDataFromFileToArray()
Dim MySource As New AutoCompleteStringCollection()
For StudentCounter = 0 To StudentCounter - 1
MySource.Add(MyStudentArray(StudentCounter).StudentName)
Next
With txtSearch
.AutoCompleteCustomSource = MySource
.AutoCompleteMode = AutoCompleteMode.SuggestAppend
.AutoCompleteSource = AutoCompleteSource.CustomSource
.Visible = True
Me.Controls.Add(txtSearch)
End With
End Sub
Private Sub lstAllStudentData_SelectedIndexChanged(sender As Object, e As EventArgs) Handles lstAllStudentData.SelectedIndexChanged
txtStudentName.Text = MyStudentArray(lstAllStudentData.SelectedIndex).StudentName
txtTest1.Text = MyStudentArray(lstAllStudentData.SelectedIndex).Test1
txtTest2.Text = MyStudentArray(lstAllStudentData.SelectedIndex).Test2
txtTest3.Text = MyStudentArray(lstAllStudentData.SelectedIndex).Test3
txtTest4.Text = MyStudentArray(lstAllStudentData.SelectedIndex).Test4
txtTest5.Text = MyStudentArray(lstAllStudentData.SelectedIndex).Test5
CalculateIndividual()
End Sub
Private Sub btnSearch_Click(sender As Object, e As EventArgs) Handles btnSearch.Click
Dim SearchField As String = txtSearch.Text
For StudentCounter = 0 To StudentCounter
If rdbStudent.Checked = True Then
If UCase(SearchField) = UCase(MyStudentArray(StudentCounter).StudentName) Then
lstAllStudentData.SelectedIndex = StudentCounter
Exit For
End If
End If
If rdbStudent.Checked = True Then
If UCase(SearchField) = UCase(MyStudentArray(StudentCounter).StudentName) Then
lstAllStudentData.SelectedIndex = StudentCounter
Exit For
End If
End If
Next
End Sub
Private Sub btnSave_Click(sender As Object, e As EventArgs) Handles btnSave.Click
Dim StudentFile As New System.IO.StreamWriter("..\..\StudentDataFile.csv")
For StudentCounter = 0 To MyStudentArray.Length - 1
StudentFile.Write(MyStudentArray(StudentCounter).StudentName)
StudentFile.Write(",")
StudentFile.Write(MyStudentArray(StudentCounter).Test1)
StudentFile.Write(",")
StudentFile.Write(MyStudentArray(StudentCounter).Test3)
StudentFile.Write(",")
StudentFile.Write(MyStudentArray(StudentCounter).Test4)
StudentFile.Write(",")
StudentFile.Write(MyStudentArray(StudentCounter).Test4)
StudentFile.Write(",")
StudentFile.WriteLine(MyStudentArray(StudentCounter).Test5)
Next
StudentFile.Close()
End Sub
End Class
I'm creating database connection in Visual Basic. When user click on "borrow book" it transfer chosen data into table used for lent books. It all works alright, but I need last thing. In my database in lent table I have attribute "End date of lent" and I want fill it everytime when user borrow a book with date today + 1 month (for instance, if now is 19/04/2016, end date will be 19/05/2016). I created method "BorrowTime" for this, but I don't know what I should type into and how can I get value of inserted row into "row". And sorry for horrible look of code and form...
Public Class frm_UserView
Dim BooksSource As New BindingSource
Dim BorrowSource As New BindingSource
Dim BooksView As New DataView
Dim BorrowView As New DataView
Dim ds As New DataSet
Dim Borrow As Byte
Private Sub frm_UserView_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
tmr_Timer.Start()
Me.LoanerBooksTableAdapter.Fill(Me.GMITLibraryDataSet1.LoanerBooks)
Me.BooksTableAdapter.Fill(Me.GMITLibraryDataSet.Books)
BooksSource = dgd_UserBookView.DataSource
BooksView = CType(BooksSource.List, DataView)
ds = BooksView.DataViewManager.DataSet.Clone
BorrowSource.DataSource = ds
BorrowSource.DataMember = "Books"
BorrowView = CType(BorrowSource.List, DataView)
dgd_User_Borrow_View.DataSource = BorrowSource
End Sub
Private Sub btn_Borrow_Click(sender As System.Object, e As System.EventArgs) Handles btn_BorrowBook.Click
Borrow = 1
MoveBooks(dgd_UserBookView, BorrowView, Borrow)
dgd_User_Borrow_View.Sort(dgd_User_Borrow_View.Columns(0), System.ComponentModel.ListSortDirection.Ascending)
BorrowSource.MoveLast()
BorrowSource.MoveLast()
End Sub
Private Sub MoveBooks(ByRef source As DataGridView, ByRef target As DataView, ByRef borrow As Byte)
For i = 0 To source.SelectedRows.Count - 1
Dim numberOfRow As Integer
Dim row As DataRowView
row = target.AddNew()
Dim col As Int16 = 0
For Each cell As DataGridViewCell In source.SelectedRows(i).Cells
row.Item(col) = cell.Value
If borrow = 1 Then
numberOfRow = 0
BorrowTime(numberOfRow, dgd_User_Borrow_View)
End If
col = col + 1
Next
Next
Dim count As Int16 = source.SelectedRows.Count
For i = 0 To count - 1
source.Rows.RemoveAt(source.SelectedRows(0).Index)
Next
End Sub
Private Sub BorrowTime(ByRef row As Integer, ByRef dgd_Table As DataGridView)
'Code for adding date
End Sub
Private Sub btn_ReturnBook_Click(sender As System.Object, e As System.EventArgs) Handles btn_ReturnBook.Click
Borrow = 0
MoveBooks(dgd_User_Borrow_View, BooksView, Borrow)
dgd_UserBookView.Sort(dgd_UserBookView.Columns(0), System.ComponentModel.ListSortDirection.Ascending)
BooksSource.MoveLast()
BooksSource.MoveLast()
End Sub
Private Sub btn_UserLogOut_Click(sender As System.Object, e As System.EventArgs) Handles btn_UserLogOut.Click
frm_Login.Show()
Me.Hide()
End Sub
Private Sub Timer1_Tick(sender As System.Object, e As System.EventArgs) Handles tmr_Timer.Tick
Dim countBooks As Integer
Dim countLent As Integer
countBooks = BooksSource.Count
countLent = BorrowSource.Count
lbl_BookCounter.Text = "There are " + countBooks.ToString + " books"
lbl_BorrowCounter.Text = "You have lent " + countLent.ToString + " books"
End Sub
End Class
I need to put code here:
Private Sub BorrowTime(ByRef row As Integer, ByRef dgd_Table As DataGridView)
'Code for adding date
End Sub
My form
Public Class frm_UserView
Dim BooksSource As New BindingSource
Dim BorrowSource As New BindingSource
Dim BooksView As New DataView
Dim BorrowView As New DataView
Dim ds As New DataSet
Dim Borrow As Byte
Private Sub frm_UserView_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
tmr_Timer.Start()
Me.LoanerBooksTableAdapter.Fill(Me.GMITLibraryDataSet1.LoanerBooks)
Me.BooksTableAdapter.Fill(Me.GMITLibraryDataSet.Books)
BooksSource = dgd_UserBookView.DataSource
BooksView = CType(BooksSource.List, DataView)
ds = BooksView.DataViewManager.DataSet.Clone
BorrowSource.DataSource = ds
BorrowSource.DataMember = "Books"
BorrowView = CType(BorrowSource.List, DataView)
dgd_User_Borrow_View.DataSource = BorrowSource
End Sub
Private Sub btn_Borrow_Click(sender As System.Object, e As System.EventArgs) Handles btn_BorrowBook.Click
Borrow = 1
MoveBooks(dgd_UserBookView, BorrowView, Borrow)
dgd_User_Borrow_View.Sort(dgd_User_Borrow_View.Columns(0), System.ComponentModel.ListSortDirection.Ascending)
BorrowSource.MoveLast()
BorrowSource.MoveLast()
End Sub
Private Sub MoveBooks(ByRef source As DataGridView, ByRef target As DataView, ByRef borrow As Byte)
For i = 0 To source.SelectedRows.Count - 1
Dim numberOfRow As Integer
Dim row As DataRowView
row = target.AddNew()
Dim col As Int16 = 0
For Each cell As DataGridViewCell In source.SelectedRows(i).Cells
row.Item(col) = cell.Value
If borrow = 1 Then
numberOfRow = 0
BorrowTime(numberOfRow, dgd_User_Borrow_View)
End If
col = col + 1
Next
Next
Dim count As Int16 = source.SelectedRows.Count
For i = 0 To count - 1
source.Rows.RemoveAt(source.SelectedRows(0).Index)
Next
End Sub
Private Sub BorrowTime(ByRef row As Integer, ByRef dgd_Table As DataGridView)
'Code for adding date
End Sub
Private Sub btn_ReturnBook_Click(sender As System.Object, e As System.EventArgs) Handles btn_ReturnBook.Click
Borrow = 0
MoveBooks(dgd_User_Borrow_View, BooksView, Borrow)
dgd_UserBookView.Sort(dgd_UserBookView.Columns(0), System.ComponentModel.ListSortDirection.Ascending)
BooksSource.MoveLast()
BooksSource.MoveLast()
End Sub
Private Sub btn_UserLogOut_Click(sender As System.Object, e As System.EventArgs) Handles btn_UserLogOut.Click
frm_Login.Show()
Me.Hide()
End Sub
Private Sub Timer1_Tick(sender As System.Object, e As System.EventArgs) Handles tmr_Timer.Tick
Dim countBooks As Integer
Dim countLent As Integer
countBooks = BooksSource.Count
countLent = BorrowSource.Count
lbl_BookCounter.Text = "There are " + countBooks.ToString + " books"
lbl_BorrowCounter.Text = "You have lent " + countLent.ToString + " books"
End Sub
End Class
I have a problem.
Now program working like this:
Reading binary file bytes. &H1E and &H1F Allowed characters only :A123456789
If in file is B or C or D or E or F....... textbox1 = bad file
That's working. Now I want to add verification in &H10.
Allowed characters only 26
If other characters textbox1 = bad file
Imports System.IO
Imports System.IO.SeekOrigin
Public Class Form1
Dim charactersAllowed As String = "A123456789"
Dim swap As String = "26"
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim OFD As New OpenFileDialog
Dim fullFile() As Byte
With OFD
.Filter = "Binary files (*.bin)|*.bin"
End With
If OFD.ShowDialog = Windows.Forms.DialogResult.OK Then
fullFile = File.ReadAllBytes(OFD.FileName)
TextBox1.AppendText(fullFile(&H1E).ToString("X2") & " ")
TextBox1.AppendText(fullFile(&H1F).ToString("X2"))
TextBox4.AppendText(fullFile(&H10).ToString("X2"))
End If
Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
Dim theText As String = TextBox1.Text
Dim Letter As String
Dim SelectionIndex As Integer = TextBox1.SelectionStart
Dim Change As Integer
For x As Integer = 0 To TextBox1.Text.Length - 1
Letter = TextBox1.Text.Substring(x, 1)
If charactersAllowed.Contains(Letter) = False Then
theText = theText.Replace(Letter, String.Empty)
Change = 1
End If
Next
TextBox1.Text = theText
TextBox1.Select(SelectionIndex - Change, 0)
End Sub
Private Sub TextBox4_TextChanged(sender As Object, e As EventArgs) Handles TextBox4.TextAlignChanged
Dim check As String = TextBox4.Text
Dim check2 As String
Dim check3 As Integer = TextBox4.SelectionStart
Dim check4 As Integer
For x As Integer = 0 To TextBox4.Text.Length - 1
check2 = TextBox4.Text.Substring(x, 1)
If swap.Contains(check2) = False Then
check = check.Replace(check2, String.Empty)
check4 = 1
End If
Next
TextBox1.Text = check
TextBox1.Select(check3 - check4, 0)
End Sub
Hard to decode, but an obvious approach is to prevent editing when the byte has the wrong value:
If OFD.ShowDialog = Windows.Forms.DialogResult.OK Then
fullFile = File.ReadAllBytes(OFD.FileName)
If fullFile(&H10) <> 26 Then
TextBox1.Text = "Bad file"
TextBox1.Enabled = False
TextBox4.Enabled = False
Else
TextBox1.Enabled = True
TextBox4.Enabled = True
'' etc...
End If
End If
The TabLoad() function doesn't seem to be working on clicking of this dynamic button. The aim of this button click event is that it deletes text from a text file and loads the form again.
Below is the complete code. The TabLoad() function is in the NextDelbtn_Click sub at the end.
Also any suggestion regarding change of code is appreciated.
Imports System.IO
Public Class Form1
Dim str As String
Dim FILE_NAME As String = "D:\1.txt"
Dim file_exists As Boolean = File.Exists(FILE_NAME)
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
If TextBox1.Text = "" Then
MsgBox("Please enter text that you want to save", MsgBoxStyle.Information, "TOCC Error")
Else
str = TextBox1.Text
Dim fs As FileStream = Nothing
If (Not File.Exists(FILE_NAME)) Then
fs = File.Create(FILE_NAME)
Using fs
End Using
End If
If File.Exists(FILE_NAME) Then
Dim sw As StreamWriter
sw = File.AppendText(FILE_NAME)
sw.WriteLine(str)
sw.Flush()
sw.Close()
TabLoad()
TextBox1.Text = ""
End If
End If
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
TabControl1.SelectedIndex = TabControl1.TabIndex + 1
End Sub
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
TabLoad()
End Sub
Private Sub Nextbtn_Click(sender As Object, e As EventArgs)
Dim s As String = DirectCast(DirectCast(sender, Button).Tag, Label).Text
Clipboard.SetText(s)
End Sub
Private Sub TabLoad()
Dim i As Integer = 1
For Each line As String In System.IO.File.ReadAllLines(FILE_NAME)
Dim NextLabel As New Label
Dim Nextbtn As New Button
Dim NextDelbtn As New Button
NextLabel.Text = line
Nextbtn.Text = "Copy"
NextDelbtn.Text = "Delete"
NextLabel.Height = 22
Nextbtn.Width = 55
Nextbtn.Height = 22
NextDelbtn.Width = 55
NextDelbtn.Height = 22
Nextbtn.BackColor = Color.WhiteSmoke
NextLabel.Tag = Nextbtn
Nextbtn.Tag = NextLabel
NextDelbtn.Tag = NextLabel
NextDelbtn.BackColor = Color.WhiteSmoke
NextLabel.BackColor = Color.Yellow
TabPage2.Controls.Add(NextLabel)
TabPage2.Controls.Add(Nextbtn)
TabPage2.Controls.Add(NextDelbtn)
NextLabel.Location = New Point(10, 10 * i + ((i - 1) * NextLabel.Height))
Nextbtn.Location = New Point(120, 10 * i + ((i - 1) * Nextbtn.Height))
NextDelbtn.Location = New Point(180, 10 * i + ((i - 1) * NextDelbtn.Height))
AddHandler Nextbtn.Click, AddressOf Me.Nextbtn_Click
AddHandler NextDelbtn.Click, AddressOf Me.NextDelbtn_Click
i += 1
Next
File.WriteAllLines(FILE_NAME,
File.ReadAllLines(FILE_NAME).Where(Function(y) y <> String.Empty))
End Sub
Private Sub NextDelbtn_Click(sender As Object, e As EventArgs)
Dim btn As Button = CType(sender, Button)
Dim s As String = (btn.Tag).Text
Dim lines() As String = IO.File.ReadAllLines(FILE_NAME)
Using sw As New IO.StreamWriter(FILE_NAME)
For Each line As String In lines
If line = s Then
line = ""
End If
sw.WriteLine(line)
Next
sw.Flush()
sw.Close()
TabLoad()
End Using
End Sub
End Class
Your problem appears to be that you're initializing new controls but you're not changing the controls on the form or even creating a new form.