Question

我正在尝试将csv文件输入到Visual Basic数据网格中。但是每次我尝试调用一个条目时它只读取第一行，目标是读取一个随机行并将名称输入到列中。

CSV文件：

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,

守则：

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

以下方法将从文件中返回指定数量的随机行：

'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

您可以调用该方法，然后遍历结果，拆分和加载。如果您只想要一行而不是多行，那么您只需拨打First或FirstOrDefault并返回String而不是数组。

关于拆分数据，如果它可能包含包含逗号的带引号的字段值，最好使用TextFieldParser。问题在于你必须先拆分每一行才能知道有多少行，这意味着多余的工作。

从CSV文件读取只返回Visual Basic中的一行

1 个答案: