问题
I wanted to create a datatable based from a 5 column datatable. Also, I would like to remove the last column (it is an image column).
Basically, what I wanted to have is ( a pseudocode )
datatable = datagridview.datasource
I have tried this, but failed:
Dim dt As New DataTable
dt = TryCast(dgvCarAccidentInjury.DataSource, DataTable)
And this,
Dim dt As New DataTable(dgvCarAccidentInjury.DataSource)
Again I failed.
I saw this on the c# column but I don't know how to convert it to vb.net, maybe this is the solution but I don't know the syntax in VB.
DataTable data = (DataTable)(dgvMyMembers.DataSource);
I can do it by manually looping but is there an easy way like how it is on C#?
EDIT I have set my datagridview's data manually by doing this line of code,
dgvCarAccidentInjury.Rows.Add(New String() {"test1", "test2", "test3", "test4"})
Also, there is a 5th column (an image column), actually it is empty. Sorry I have missed this important point out.
EDIT
the solution for this problem is this, by manually looping.
Dim dt As New DataTable
Dim r As DataRow
dt.Columns.Add("a", Type.GetType("System.String"))
dt.Columns.Add("b", Type.GetType("System.String"))
dt.Columns.Add("c", Type.GetType("System.String"))
dt.Columns.Add("d", Type.GetType("System.String"))
For i = 0 To dgvCarAccidentInjury.Rows.Count - 1
r = dt.NewRow
r("a") = dgvCarAccidentInjury.Item(0, i).Value.ToString
r("b") = dgvCarAccidentInjury.Item(1, i).Value.ToString
r("c") = dgvCarAccidentInjury.Item(2, i).Value.ToString
r("d") = dgvCarAccidentInjury.Item(3, i).Value.ToString
dt.Rows.Add(r)
Next
Other solutions:
Dim dt As New DataTable
dt = TryCast(yourdatagridview.DataSource, DataTable)
回答1:
Your problem is not the casting:
dt = TryCast(dgvMyMembers.DataSource, DataTable)
But your DataSource is NOT a DataTable but an array of String:
dgvCarAccidentInjury.Rows.Add(New String() {"test1", "test2", "test3", "test4"})
So, make sure that your DataGridView was properly connected a DataTable source FIRST, like:
dgvMyMembers.DataSource = dtSourceHere
Probably do it your Form_Load()
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
dgvMyMembers.DataSource = dtSourceHere
End Sub
If you want to add your string to your DataGridView, you are better off creating the DataTable add those strings, like:
Dim dt As New DataTable
dt.Columns.Add("Names", GetType(String))
dt.Rows.Add("test1")
dt.Rows.Add("test2")
dt.Rows.Add("test3")
dt.Rows.Add("test4")
Then make it as the DataSource of your DataGridView:
dgvMyMembers.DataSource = dt
You could do then later on the TryCast() that you desired:
Dim dtNew As New DataTable
dtNew = TryCast(dgvMyMembers.DataSource, DataTable)
回答2:
Dim DtGrid As DataTable
DtGrid = CType(dgrd_WWWH.DataSource, DataTable).Copy()
回答3:
Did you try cloning the table? If you set the DataSource with a DataTable you clone the original. If you have a diff DataSource - it will not work converting the DataSource.
DataTable.Clone
Dim dt As DataTable = originalDt.Clone()
回答4:
--MENU--
Dim login As New LoginClass
login.ShowDialog()
--CONEXION--
Private conec As SqlConnection
Dim stringCon As String = "Data Source= ;Initial Catalog=;Persist Security Info=True;User ID=;Password="
Public ReadOnly Property prConec() As Object
Get
Return conec
End Get
End Property
Public Sub Conectar()
Try
conec = New SqlConnection(stringCon)
If conec.State <> ConnectionState.Open Then
conec.Open()
End If
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
--BUSCAR--
funciones.Conectar()
Dim coman As New SqlCommand("sp_cliente", funciones.prConec)
Dim dt As New DataTable
coman.CommandType = CommandType.StoredProcedure
coman.Parameters.Add("@i_operacion", SqlDbType.Char, 1, ParameterDirection.Input).Value = "B"
dt.Load(coman.ExecuteReader())
grdClientes.DataSource = dt
--INSERTAR--
funciones.Conectar()
Dim coman As New SqlCommand("sp_articulo", funciones.prConec)
coman.CommandType = CommandType.StoredProcedure
coman.Parameters.Add("@i_operacion", SqlDbType.Char, 1, ParameterDirection.Input).Value = "I"
coman.ExecuteNonQuery()
Buscar()
Limpiar()
--COMBO--
Dim dt As New DataTable
dt.Columns.Add("Codigo")
dt.Columns.Add("Descripcion")
Dim dr1 As DataRow = dt.NewRow
dr1.Item("Codigo") = "A"
dr1.Item("Descripcion") = "Activo"
dt.Rows.Add(dr1)
Dim dr2 As DataRow = dt.NewRow
dr2.Item("Codigo") = "I"
dr2.Item("Descripcion") = "Inactivo"
dt.Rows.Add(dr2)
cmbEstado.DataSource = dt
cmbEstado.ValueMember = "Codigo"
cmbEstado.DisplayMember = "Descripcion"
--GRIDVIEW--
--1--
Dim grdFila As DataGridViewRow = grdClientes.CurrentRow
txtCedula.Text = grdFila.Cells(0).Value
--2--
If DataGridProductos.CurrentCell.ColumnIndex = 0 Then
Dim FLstArticulos As New FLstArticulos
FLstArticulos.ShowDialog()
DataGridProductos.CurrentRow.Cells(0).Value = FLstArticulos.PrIdArticulo
End If
--GRIDVIEW.CELLENDEDIT--
If DataGridProductos.CurrentCell.ColumnIndex = 3 Then
Dim precio As New Double
Dim cantidad As New Double
precio = CDbl(grdRow.Cells(2).Value)
cantidad = CDbl(grdRow.Cells(3).Value)
DataGridProductos.CurrentRow.Cells(4).Value = PLTotalFilaItem(cantidad, precio)
PLCargaTotales()
End If
Sub PLCargaTotales()
Dim subTotal As Double
Dim iva As Double
For Each grd As DataGridViewRow In DataGridProductos.Rows
If Not String.IsNullOrEmpty(grd.Cells(4).Value) Then
subTotal = subTotal + CDbl(grd.Cells(4).Value)
End If
Next grd
txtSubtotal.Text = subTotal.ToString
iva = Decimal.Round(subTotal * 0.12)
txtIva.Text = iva.ToString
txtTotalPagar.Text = (subTotal + iva).ToString
End Sub
回答5:
I've tried this method and it works properly.
Dim dt As New DataTable
Dim dc As DataColumn = New DataColumn("MOBILENUMBER")
dc.DataType = System.Type.GetType("System.String")
dc.MaxLength = 15
dt.Columns.Add(dc)
For n As Integer = 0 To dgvMobiles.Rows.Count - 2
dtr = dt.NewRow()
dtr.Item("MOBILENUMBER") = dgvMobiles.Rows(n).Cells(0).Value
dt.Rows.Add(dtr)
Next
Where dgbMobiles is the datagridview which i can enter my contacts mobile numbers.
I hope that is usu
来源：https://stackoverflow.com/questions/20209241/vb-net-datagridview-to-datatable