我有以下代码写入由 10 行分隔的三个等级逗号的 .txt 文件。（每一行看起来像这样，94,57,84，）这段代码可以很好地写入文件，但我不知道如何让它平均分数。我绝对需要它来平均放在文本框中的 30 个分数，但我希望它也能平均每一行。我的 GUI 在我手动运行程序时执行此操作，但在我拉入我制作的文本文件时不会执行此操作。这是我的代码。第一部分将是我编写的代码，第二部分将是我的所有代码。感谢您提供任何有用的建议。
这是直接来自书中的代码。我所做的只是添加两个按钮和最后两个按钮的代码。我还在类之前添加了 Import system IO 和 Dim 文件名的公共 dim 语句作为字符串。它会在没有差异的情况下写入，但是当我调用提交按钮时，它会在“grades(studentCount,0)=Concert.toInt32(test1TestBox.Text) 出现错误，所以我只从底部添加了数组代码行 3、4、5。不过，这给了我一个“0”的平均计算。这是直接来自书中的代码，除了显示和打开按钮代码
Imports System.IO ' using classes from this namespace
Public Class GradeReport
Dim fileName As String ' name of file containing account data
Dim grades(9, 2) As Integer ' stores 10 students' grades on 3 tests
Dim studentCount As Integer = 0 ' number of students entered
' display heading in gradeListBox
Private Sub GradeReport_Load(sender As Object,
e As EventArgs) Handles MyBase.Load
' headings row for gradesListBox
gradesListBox.Items.Add(vbTab & vbTab & "Test 1" & vbTab &
"Test 2" & vbTab & "Test 3" & vbTab & "Average")
End Sub
' process one student's grades
Private Sub submitButton_Click(sender As Object,
e As EventArgs) Handles submitButton.Click
' retrieve the student's grades
grades(studentCount, 0) = Convert.ToInt32(test1TextBox.Text)
grades(studentCount, 1) = Convert.ToInt32(test2TextBox.Text)
grades(studentCount, 2) = Convert.ToInt32(test3TextBox.Text)
' begin creating String containing the student's grades and average
Dim output As String = "Student " & studentCount & vbTab
' append each test grade to the output
For column = 0 To grades.GetUpperBound(1)
' if the Letter RadioButton is checked
If letterRadioButton.Checked = True Then
' append letter grade to the output
output &= vbTab & LetterGrade(grades(studentCount, column))
Else
' append number grade to the output
output &= vbTab & grades(studentCount, column)
End If
Next
' append the student's test average to the output
output &= vbTab & CalculateStudentAverage(studentCount)
gradesListBox.Items.Add(output) ' add output to the ListBox
studentCount += 1 ' update number of students entered
averageLabel.Text = CalculateClassAverage() ' display class average
DisplayBarChart() ' display the current grade distribution
' clear the input TextBoxes and set focus to first TextBox
test1TextBox.Clear()
test2TextBox.Clear()
test3TextBox.Clear()
test1TextBox.Focus()
' limit number of students
If studentCount = grades.GetUpperBound(0) + 1 Then
inputGradesGroupBox.Enabled = False ' disable GroupBox's controls
End If
End Sub ' submitButton_Click
' handles Numeric and Letter RadioButtons' CheckChanged events
Private Sub RadioButton_CheckedChanged(sender As Object,
e As EventArgs) _
Handles numericRadioButton.CheckedChanged,
letterRadioButton.CheckedChanged
' if there are grades to display, call DisplayClassGrades
If studentCount > 0 Then
DisplayClassGrades()
End If
End Sub ' RadioButton_CheckedChanged
' calculates a student's test average
Function CalculateStudentAverage(row As Integer) As String
Dim gradeTotal As Integer = 0 ' student's total grade
' sum the grades for the student
For column = 0 To grades.GetUpperBound(1)
gradeTotal += grades(row, column)
Next
Dim studentAverage As String = String.Empty ' output string
' calculate the student's test average
If letterRadioButton.Checked = True Then
studentAverage =
LetterGrade(gradeTotal / (grades.GetUpperBound(1) + 1))
Else
studentAverage = String.Format("{0:F}",
(gradeTotal / (grades.GetUpperBound(1) + 1)))
End If
Return studentAverage ' return the student's average
End Function ' CalculateStudentAverage
' calculates the class average
Function CalculateClassAverage() As String
Dim classTotal As Integer = 0 ' class's total grade
' loop through all rows that currently contain grades
For row = 0 To studentCount - 1
' loop through all columns
For column = 0 To grades.GetUpperBound(1)
classTotal += grades(row, column) ' add grade to total
Next column
Next row
Dim classAverage As String = String.Empty ' output string
' if the Letter RadioButton is checked, return letter grade
If letterRadioButton.Checked = True Then
classAverage = LetterGrade(classTotal /
(studentCount * (grades.GetUpperBound(1) + 1)))
Else ' return numeric grade
classAverage = String.Format("{0:F}", (classTotal /
(studentCount * (grades.GetUpperBound(1) + 1))))
End If
Return classAverage ' return the class average
End Function ' CalculateClassAverage
' determines a letter grade corresponding to a numeric grade
Function LetterGrade(grade As Double) As String
Dim output As String ' the letter grade to return
' determine the correct letter grade
Select Case grade
Case Is >= 90
output = "A"
Case Is >= 80
output = "B"
Case Is >= 70
output = "C"
Case Is >= 60
output = "D"
Case Else
output = "F"
End Select
Return output ' return the letter grade
End Function ' LetterGrade
' display the grades for all students entered
Sub DisplayClassGrades()
gradesListBox.Items.Clear() ' clear the ListBox
' add the header to the ListBox
gradesListBox.Items.Add(vbTab & vbTab & "Test 1" & vbTab &
"Test 2" & vbTab & "Test 3" & vbTab & "Average")
' loop through all the rows
For row = 0 To studentCount - 1
Dim output As String = "Student " & row & vbTab
' loop through all the columns
For column = 0 To grades.GetUpperBound(1)
If letterRadioButton.Checked = True Then
' add letter grade to output string
output &= vbTab & LetterGrade(grades(row, column))
Else
' add number grade to output string
output &= vbTab & (grades(row, column))
End If
Next column
' add the student's average to the output
output &= vbTab & CalculateStudentAverage(row)
' add the output to the ListBox
gradesListBox.Items.Add(output)
Next row
' update the class average
averageLabel.Text = CalculateClassAverage()
End Sub ' DisplayClassGrades
' display a bar chart of the grade distribution
Sub DisplayBarChart()
barChartListBox.Items.Clear() ' remove current items
' stores frequency of grades in each range of 10 grades
Dim frequency(10) As Integer
' for each grade, increment the appropriate frequency
For row = 0 To studentCount - 1
For column = 0 To grades.GetUpperBound(1)
frequency(grades(row, column) \ 10) += 1
Next column
Next row
' for each grade frequency, display bar of asterisks
For count = 0 To frequency.GetUpperBound(0)
Dim bar As String ' stores the label and bar
' create bar label ( "00-09: ", ..., "90-99: ", "100: " )
If count = 10 Then
bar = String.Format("{0, 5:D}: ", 100)
Else
bar = String.Format("{0, 2:D2}-{1, 2:D2}: ",
count * 10, count * 10 + 9)
End If
' append bar of asterisks
For stars = 1 To frequency(count)
bar &= ("*")
Next
barChartListBox.Items.Add(bar) ' display bar
Next count
End Sub ' DisplayBarChart
Private Sub Open_Click(sender As Object, e As EventArgs) Handles Open.Click
' opens a file in which accounts are stored
Dim result As DialogResult ' stores result of Open dialog
' create dialog box enabling user to open file
Using fileChooser As New OpenFileDialog()
result = fileChooser.ShowDialog()
fileName = fileChooser.FileName ' get specified file name
End Using ' automatic call to fileChooser.Dispose() occurs here
' if user did not click Cancel, enable Buttons
If result <> Windows.Forms.DialogResult.Cancel Then
Display.Enabled = True
End If
End Sub ' OpenToolStripMenuItem_Click
Private Sub Display_Click(sender As Object, e As EventArgs) Handles Display.Click
' display accounts of specified type
Dim fileReader As StreamReader = Nothing
' read and display file information
Try
gradesListBox.Text = "The accounts are:" & vbCrLf
' open file for reading
fileReader = New StreamReader(fileName)
' read file and display lines that match the balance type
Do While Not fileReader.EndOfStream ' while not end of file
Dim line As String = fileReader.ReadLine() ' read line
Dim fields() As String = line.Split(","c) ' split into fields
'Dim fields() As String = line.Split(CChar(","))
' get data from fields array
Dim Test1 As String = fields(0) 'Integer = Convert.ToInt32(fields(0))
Dim Test2 As String = fields(1)
Dim Test3 As String = fields(2)
' If ShouldDisplay(balance, accountType) Then
gradesListBox.Items.Add(vbTab & vbTab & Test1 & vbTab &
Test2 & vbTab & Test3 & vbCrLf)
Loop
Catch ex As IOException
MessageBox.Show("Cannot Read File", "Error",
MessageBoxButtons.OK, MessageBoxIcon.Error)
Finally ' ensure that file gets closed
If fileReader IsNot Nothing Then
Try
fileReader.Close() ' close StreamReader
Catch ex As IOException
MessageBox.Show("Error closing file", "Error",
MessageBoxButtons.OK, MessageBoxIcon.Error)
End Try
End If
End Try
' submitButton.PerformClick
studentCount += 1 ' update number of students entered
averageLabel.Text = CalculateClassAverage() ' display class average
DisplayBarChart() ' display the current grade distribution
End Sub ' submitButton_Click
结束班级'成绩报告