如何在 Visual Basic 2010 中读取 CSV 文件并在网格中显示结果？

Question

如何在 Visual Basic 2010 中读取 CSV 文件并在网格中显示结果？这听起来很简单，但谷歌搜索了一段时间后我仍然找不到答案。我在表单上有 DataGridView，它称为 DataGridView1。我有一个只有 3 列数据的 CSV 文件，我希望能够显示它们。

Answer 1

使用 .Net 中内置的 TextFieldParser 类框架。

以下是从 MSDN 论坛帖子复制的一些代码保罗·克莱门特著。它将 CSV 转换为新的内存中 DataTable，然后将 DataGridView 绑定到 DataTable

    Dim TextFileReader As New Microsoft.VisualBasic.FileIO.TextFieldParser("C:\Documents and Settings\...\My Documents\My Database\Text\SemiColonDelimited.txt")

    TextFileReader.TextFieldType = FileIO.FieldType.Delimited
    TextFileReader.SetDelimiters(";")

    Dim TextFileTable As DataTable = Nothing

    Dim Column As DataColumn
    Dim Row As DataRow
    Dim UpperBound As Int32
    Dim ColumnCount As Int32
    Dim CurrentRow As String()

    While Not TextFileReader.EndOfData
        Try
            CurrentRow = TextFileReader.ReadFields()
            If Not CurrentRow Is Nothing Then
                ''# Check if DataTable has been created
                If TextFileTable Is Nothing Then
                    TextFileTable = New DataTable("TextFileTable")
                    ''# Get number of columns
                    UpperBound = CurrentRow.GetUpperBound(0)
                    ''# Create new DataTable
                    For ColumnCount = 0 To UpperBound
                        Column = New DataColumn()
                        Column.DataType = System.Type.GetType("System.String")
                        Column.ColumnName = "Column" & ColumnCount
                        Column.Caption = "Column" & ColumnCount
                        Column.ReadOnly = True
                        Column.Unique = False
                        TextFileTable.Columns.Add(Column)
                    Next
                End If
                Row = TextFileTable.NewRow
                For ColumnCount = 0 To UpperBound
                    Row("Column" & ColumnCount) = CurrentRow(ColumnCount).ToString
                Next
                TextFileTable.Rows.Add(Row)
            End If
        Catch ex As _
        Microsoft.VisualBasic.FileIO.MalformedLineException
            MsgBox("Line " & ex.Message & _
            "is not valid and will be skipped.")
        End Try
    End While
    TextFileReader.Dispose()
    frmMain.DataGrid1.DataSource = TextFileTable

Answer 2

考虑这段代码。根据您认为合适或满足您的要求进行修改。您需要为 System.IO 和 System.Data.OleDb 提供 Imports 语句。

Dim fi As New FileInfo("c:\foo.csv")
Dim connectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Extended Properties=Text;Data Source=" & fi.DirectoryName

Dim conn As New OleDbConnection(connectionString)
conn.Open()

'the SELECT statement is important here, 
'and requires some formatting to pull dates and deal with headers with spaces.
Dim cmdSelect As New OleDbCommand("SELECT Foo, Bar, FORMAT(""SomeDate"",'YYYY/MM/DD') AS SomeDate, ""SOME MULTI WORD COL"", FROM " & fi.Name, conn)

Dim adapter1 As New OleDbDataAdapter
adapter1.SelectCommand = cmdSelect

Dim ds As New DataSet
adapter1.Fill(ds, "DATA")

myDataGridView.DataSource = ds.Tables(0).DefaultView 
myDataGridView.DataBind
conn.Close()

Answer 3

考虑这篇 CodeProject 文章/项目：LINQ TO CSV。

它将使您能够创建形状类似于 .csv 文件的列的自定义类。然后，您将使用 CSV 并绑定到您的 DataGridView。

Dim cc As new CsvContext()
Dim inputFileDescription As New CsvFileDescription() With { _
    .SeparatorChar = ","C, _
    .FirstLineHasColumnNames = True _
}

Dim products As IEnumerable(Of Product) = _
     cc.Read(Of Product)("products.csv", inputFileDescription)

' query from CSV, load into a new class of your own   
Dim productsByName = From p In products
    Select New CustomDisplayClass With _
       {.Name = p.Name, .SomeDate = p.SomeDate, .Price = p.Price}, _        
    Order By p.Name


myDataGridView1.DataSource = products
myDataGridView1.DataBind()

Answer 4

For Each line As String In System.IO.File.ReadAllLines("D:\abc.csv")
    DataGridView1.Rows.Add(line.Split(","))
Next

Answer 5

这看起来更优雅一点

'populate DT from .csv file

 Dim items = (From line In IO.File.ReadAllLines("C:YourData.csv") _
 Select Array.ConvertAll(line.Split(","c), Function(v) _ 
 v.ToString.TrimStart(""" ".ToCharArray).TrimEnd(""" ".ToCharArray))).ToArray

Dim Your_DT As New DataTable
For x As Integer = 0 To items(0).GetUpperBound(0)
Your_DT.Columns.Add()
Next

For Each a In items
Dim dr As DataRow = Your_DT.NewRow
dr.ItemArray = a
Your_DT.Rows.Add(dr)
Next

Your_DataGrid.DataSource = Your_DT           

Answer 6

这是您使用 OLEDB 提供程序从 .csv 文件读取数据的方法。

  If OpenFileDialog1.ShowDialog(Me) = DialogResult.OK Then
        Try
            Dim fi As New FileInfo(OpenFileDialog1.FileName)
            Dim sConnectionStringz As String = "Provider=Microsoft.Jet.OLEDB.4.0;Extended Properties=Text;Data Source=" & fi.DirectoryName
            Dim objConn As New OleDbConnection(sConnectionStringz)
            objConn.Open()
            'DataGridView1.TabIndex = 1
            Dim objCmdSelect As New OleDbCommand("SELECT * FROM " & fi.Name, objConn)
            Dim objAdapter1 As New OleDbDataAdapter
            objAdapter1.SelectCommand = objCmdSelect
            Dim objDataset1 As New DataSet
            objAdapter1.Fill(objDataset1)

            '--objAdapter1.Update(objDataset1) '--updating
            DataGridView1.DataSource = objDataset1.Tables(0).DefaultView
        Catch ex as Exception
           MsgBox("Error: " + ex.Message)
        Finally
            objConn.Close()
        End Try
    End If

Answer 7

执行以下操作：

Dim dataTable1 As New DataTable
                dataTable1.Columns.Add("FECHA")
                dataTable1.Columns.Add("TT")
                dataTable1.Columns.Add("DESCRIPCION")
                dataTable1.Columns.Add("No. DOC")
                dataTable1.Columns.Add("DEBE")
                dataTable1.Columns.Add("HABER")
                dataTable1.Columns.Add("SALDO")

For Each line As String In System.IO.File.ReadAllLines(objetos.url)
                    dataTable1.Rows.Add(line.Split(","))
                Next