从CSV文件读取仅在Visual Basic中返回一行

Question

I am trying to input a csv file into a Visual Basic Data Grid. But each time I try to call an entry it only reads the first Line, The goal is to read a random line and input the name into the Column.

The CSV File:

Noah,
Liam,
Mason,
Jacob,
William,
Ethan,
James,
Alexander,
Michael,
Benjamin,
Elijah,
Daniel,
Aiden,
Logan,
Matthew,
Lucas,
Jackson,
David,
Oliver,
Jayden,
Joseph,
Gabriel,
Samuel,
Carter,
Anthony,
John,
Dylan,
Luke,
Henry,
Andrew,
Isaac,
Christopher,
Joshua,
Wyatt,
Sebastian,
Owen,
Caleb,
Nathan,
Ryan,
Jack,
Hunter,
Levi,
Christian,
Jaxon,
Julian,
Landon,
Grayson,
Jonathan,
Isaiah,
Charles,
Thomas,
Aaron,
Eli,
Connor,
Jeremiah,
Cameron,
Josiah,
Adrian,
Colton,
Jordan,
Brayden,
Nicholas,
Robert,
Angel,
Hudson,
Lincoln,
Evan,
Dominic,
Austin,
Gavin,
Nolan,
Parker,
Adam,
Chase,
Jace,
Ian,
Cooper,
Easton,
Kevin,
Jose,
Tyler,
Brandon,
Asher,
Jaxson,
Mateo,
Jason,
Ayden,
Zachary,
Carson,
Xavier,
Leo,
Ezra,
Bentley,
Sawyer,
Kayden,
Blake,
Nathaniel,
Ryder,
Theodore,
Elias,
Tristan,
Roman,
Leonardo,
Camden,
Brody,
Luis,
Miles,
Micah,
Vincent,
Justin,
Greyson,
Declan,
Maxwell,
Juan,
Cole,

The Code:

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

    ' Initialize the random-number generator
    DataGridView1.Rows.Clear()

    For ix As Integer = 1 To 115

        Dim intValue As Integer = CInt(Int((5000 * Rnd()) + 1))
        Dim intRandomNumber As Integer
        Dim randomName As String = 0

        intRandomNumber = (100 * Rnd())
        Dim dat(230) As String 'This array holds each item from csv ile
        Dim num As Integer = 0
        Dim c, p, z As Integer
        Dim firstNames(115) As String
        Dim blankSpace(115) As Integer
        Using MyReader As New Microsoft.VisualBasic.FileIO.TextFieldParser("firstNames.txt")
            MyReader.TextFieldType = FileIO.FieldType.Delimited
            MyReader.SetDelimiters(",")
            Dim currentRow As String()

            'This section reads the text file into one array dat()
            While Not MyReader.EndOfData
                Try
                    currentRow = MyReader.ReadFields()
                    For Each currentField In currentRow
                        num = num + 1
                        dat(num) = currentField
                    Next
                    'error reporting
                Catch ex As Microsoft.VisualBasic.FileIO.MalformedLineException
                    MsgBox("Line " & ex.Message & "is not valid and will be skipped.")
                End Try
            End While
            p = 0
            For c = 1 To num Step 2
                p = p + 1
                firstNames(p) = dat(c)
            Next
        End Using
        For c = 1 To p
            DataGridView1.Rows.Add(Format(ix, "00000"), firstNames(c), "", "", "", intValue)
        Next
    Next
End Sub

Answer 1

The following method will return a specified number of random lines from a file:

'Random number generator.
Private rng As New Random

Private Function GetRandomLines(filePath As String, lineCount As Integer) As String()
    Return IO.File.ReadAllLines(filePath).
                   OrderBy(Function(s) rng.NextDouble()).
                   Take(lineCount).
                   ToArray()

End Function

You can call that method and then loop through the results, splitting and loading. If you only want one line rather than multiple then you can just call First or FirstOrDefault and return a String instead of an array.

With regards to splitting the data, it would be preferable to use a TextFieldParser if it might contain quoted field values that contain commas. The problem with that is that you would have to split every line before you could know how many there are, which means redundant work.