Visual Basic 2010でCSVファイルを読み取り、グリッドに結果を表示するにはどうすればよいですか?これはとても簡単に聞こえますが、しばらくグーグルで調べてもまだ答えが見つかりません。フォームにDataGridViewがあり、DataGridView1と呼ばれます。データが3列だけのcsvがあり、それらを表示できるようにしたいと考えています。
.Netフレームワークに組み込まれている TextFieldParser クラスを使用します。
Paul Clementによる MSDNフォーラム投稿 からコピーしたコードを次に示します。 CSVを新しいメモリ内DataTableに変換し、DataGridViewをDataTableにバインドします
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
このコードのスニペットを検討してください。必要に応じて、または要件に合わせて変更します。 System.IO
およびSystem.Data.OleDb
のImports
ステートメントが必要です。
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()
このCodeProjectの記事/プロジェクトを考慮してください: LINQ TO CSV 。
.csvファイルの列のような形のカスタムクラスを作成できます。次に、CSVを使用してDataGridViewにバインドします。
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()
For Each line As String In System.IO.File.ReadAllLines("D:\abc.csv")
DataGridView1.Rows.Add(line.Split(","))
Next
これは、OLEDB
プロバイダーを使用して.csv
ファイルからデータを読み取る方法です。
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
これはもう少しエレガントに見える
'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
以下をせよ:
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