BindingSource.RemoveAt(Int32) Metode
Definisi
Penting
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Menghapus item pada indeks yang ditentukan dalam daftar.
public:
virtual void RemoveAt(int index);
public virtual void RemoveAt (int index);
abstract member RemoveAt : int -> unit
override this.RemoveAt : int -> unit
Public Overridable Sub RemoveAt (index As Integer)
Parameter
- index
- Int32
Indeks berbasis nol dari item yang akan dihapus.
Penerapan
Pengecualian
index
kurang dari nol atau lebih besar dari Count nilai properti .
Daftar yang mendasar yang diwakili oleh List properti bersifat baca-saja atau memiliki ukuran tetap.
Contoh
Contoh kode berikut menunjukkan Listanggota , , RemoveAtdan Count . Untuk menjalankan contoh ini, tempelkan kode ke dalam formulir yang berisi BindingSource bernama BindingSource1
, dua label bernama label1
dan label2
, dan tombol bernama button1
. Kaitkan button1_Click
metode dengan Click peristiwa untuk button1
. Pengguna Visual Basic perlu menambahkan referensi ke System.Data.dll.
private void button1_Click(object sender, EventArgs e)
{
// Create the connection string, data adapter and data table.
SqlConnection connectionString =
new SqlConnection("Initial Catalog=Northwind;" +
"Data Source=localhost;Integrated Security=SSPI;");
SqlDataAdapter customersTableAdapter =
new SqlDataAdapter("Select * from Customers", connectionString);
DataTable customerTable = new DataTable();
// Fill the adapter with the contents of the customer table.
customersTableAdapter.Fill(customerTable);
// Set data source for BindingSource1.
BindingSource1.DataSource = customerTable;
// Set the label text to the number of items in the collection before
// an item is removed.
label1.Text = "Starting count: " + BindingSource1.Count.ToString();
// Access the List property and remove an item.
BindingSource1.List.RemoveAt(4);
// Remove an item directly from the BindingSource.
// This is equivalent to the previous line of code.
BindingSource1.RemoveAt(4);
// Show the new count.
label2.Text = "Count after removal: " + BindingSource1.Count.ToString();
}
Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) _
Handles button1.Click
' Create the connection string, data adapter and data table.
Dim connectionString As New SqlConnection("Initial Catalog=Northwind;" & _
"Data Source=localhost;Integrated Security=SSPI;")
Dim customersTableAdapter As New SqlDataAdapter("Select * from Customers", _
connectionString)
Dim customerTable As New DataTable()
' Fill the adapter with the contents of the customer table.
customersTableAdapter.Fill(customerTable)
' Set data source for BindingSource1.
BindingSource1.DataSource = customerTable
' Set the label text to the number of items in the collection before
' an item is removed.
label1.Text = "Starting count: " + BindingSource1.Count.ToString()
' Access the List property and remove an item.
BindingSource1.List.RemoveAt(4)
' Remove an item directly from the BindingSource.
' This is equivalent to the previous line of code.
BindingSource1.RemoveAt(4)
' Show the new count.
label2.Text = "Count after removal: " + BindingSource1.Count.ToString()
End Sub
End Class
Keterangan
Kedua kondisi ini masing-masing dapat diuji dengan IsFixedSize properti dan IsReadOnly .
Metode ini meningkatkan ListChanged peristiwa.