BindingSource.Count 屬性

定義

命名空間:

System.Windows.Forms

組件:

System.Windows.Forms.dll

來源:

BindingSource.cs

取得底層清單中項目的總數，並考慮當前 Filter 值。

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

Int32

底層清單中篩選項目的總數。

實作

Count

屬性

BrowsableAttribute

範例

以下程式碼範例展示了 List、 RemoveAt和 Count 成員。 要執行此範例，將程式碼貼入包含BindingSource一個名為 BindingSource1、 的兩個標籤 label2label1 和 ，以及一個名為 button1的按鈕 的表單中。 將方法 button1_Click 與 Click 事件 button1關聯。 Visual Basic 使用者需要為 System.Data.dll新增參考。

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

該 Count 屬性會得到該屬性所代表 List 的底層清單中項目數量，並會因屬性 Filter 的價值而改變。

另請參閱

• List
• Position
• Current