如何将 Databound Gridview 转换为 Datatable？

Question

I am trying to add row to my datagridview which is databound

Code:

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
    'Dim Index As Integer
    'Index = DataTable1DataGridView.CurrentCell.RowIndex
    Dim dt As DataTable = DataTable1DataGridView.DataSource
    Dim dr As DataRow = dt.NewRow
    dt.Rows.Add(dr)

End Sub

Error: Unable to cast object of type 'System.Windows.Forms.BindingSource' to type 'System.Data.DataTable'.

Answer 1

here

Dim dt As DataTable = DataTable1DataGridView.DataSource

you have DataSource is object and it points to System.Windows.Forms.BindingSource , not DataTable .

you need to get DataSource of the BindingSource

dim ds as DataSet = 
    DirectCast(DirectCast(DataTable1DataGridView.DataSource, BindingSource).DataSource, DataSet)

Answer 2

You're doing it all wrong. You have a BindingSource for a reason so use it. You don't need to access the DataTable at all. Just use the BindingSource , which you should be able to refer to directly, so you don't need the grid either.

Dim rowView = DirectCast(DataTable1BindingSource.AddNew(), DataRowView)

rowView("SomeColumn") = someValue
DataTable1BindingSource.EndEdit()

When you bind a DataTable , the data actually comes from the DefaultView property, which is a DataView . That's why each item is a DataRowView rather than a DataRow . You can treat a DataRowView just like you do a DataRow in many situations, including this one. If you have a typed DataSet though, you might prefer to use a typed DataRow . In that case, get the DataRow from the Row property of the DataRowView and cast it as the appropriate type:

Dim rowView = DirectCast(DataTable1BindingSource.AddNew(), DataRowView)
Dim row = DirectCast(rowView.Row, DataTable1DataRow)

rowView.SomeColumn = someValue
DataTable1BindingSource.EndEdit()