BindingSource.Count 屬性
定義
public:
virtual property int Count { int get(); };
[System.ComponentModel.Browsable(false)]
public virtual int Count { get; }
[<System.ComponentModel.Browsable(false)>]
member this.Count : int
Public Overridable ReadOnly Property Count As Integer
屬性值
基礎清單中的篩選項目總數。The total number of filtered items in the underlying list.
實作
- 屬性
範例
下列程式碼範例示範 List 、 RemoveAt 和 Count 成員。The following code example demonstrates the List, RemoveAt, and Count members. 若要執行這個範例,請將程式碼貼到包含名 BindingSource 為 BindingSource1
和的兩個標籤的表單中, label1
以及名為的 label2
按鈕 button1
。To run this example, paste the code into a form that contains a BindingSource named BindingSource1
, two labels named label1
and label2
, and a button named button1
. 將 button1_Click
方法與的 Click 事件產生關聯 button1
。Associate the button1_Click
method with the Click event for button1
. Visual Basic 使用者將需要新增 System.Data.dll 的參考。Visual Basic users will need to add a reference to 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
備註
屬性會取得屬性所 Count 表示之基礎清單中的專案數,由 List 屬性的值修改 Filter 。The Count property gets the number of items in the underlying list represented by the List property as modified by the value of the Filter property.