BindingsCollection 類別

定義

命名空間:

System.Windows.Forms

組件:

System.Windows.Forms.dll

來源:

BindingsCollection.cs

代表一組 Binding 對照項的物件集合。

public ref class BindingsCollection : System::Windows::Forms::BaseCollection

public class BindingsCollection : System.Windows.Forms.BaseCollection

type BindingsCollection = class
    inherit BaseCollection

Public Class BindingsCollection
Inherits BaseCollection

繼承

Object

MarshalByRefObject

BaseCollection

BindingsCollection

衍生

System.Windows.Forms.ControlBindingsCollection

範例

以下範例將 Text 控制項的屬性 TextBox 綁定到資料庫中的欄位。

private:
   void BindTextBoxControl()
   {
      DataSet^ myDataSet = gcnew DataSet;
      /* Insert code to populate the DataSet with tables, 
      columns, and data. */

      // Creates a new Binding object. 
      Binding^ myBinding = gcnew Binding(
         "Text",myDataSet,"customers.custToOrders.OrderAmount" );
      
      // Adds event delegates for the Parse and Format events.
      myBinding->Parse += gcnew ConvertEventHandler( this, &Form1::CurrencyToDecimal );
      myBinding->Format += gcnew ConvertEventHandler( this, &Form1::DecimalToCurrency );
      
      // Adds the new Binding to the BindingsCollection.
      text1->DataBindings->Add( myBinding );
   }

   void DecimalToCurrency( Object^ /*sender*/, ConvertEventArgs^ cevent )
   {
      /* This method is the Format event handler. Whenever the 
      control displays a new value, the value is converted from 
      its native Decimal type to a string. The ToString method 
      then formats the value as a Currency, by using the 
      formatting character "c". */
      cevent->Value = safe_cast<Decimal ^>(cevent->Value)->ToString(  "c" );
   }

   void CurrencyToDecimal( Object^ /*sender*/, ConvertEventArgs^ cevent )
   {
      /* This method is the Parse event handler. The Parse event 
      occurs whenever the displayed value changes. The static 
      Parse method of the Decimal structure converts the 
      string back to its native Decimal type. */
      cevent->Value = Decimal::Parse( cevent->Value->ToString(),
         NumberStyles::Currency, nullptr );
   }

private void BindTextBoxControl()
{
   DataSet myDataSet = new DataSet();
   /* Insert code to populate the DataSet with tables, 
   columns, and data. */

   // Creates a new Binding object. 
   Binding myBinding = new Binding
   ("Text", myDataSet, "customers.custToOrders.OrderAmount");

   // Adds event delegates for the Parse and Format events.
   myBinding.Parse += new ConvertEventHandler(CurrencyToDecimal);
   myBinding.Format += new ConvertEventHandler(DecimalToCurrency);

   // Adds the new Binding to the BindingsCollection.
   text1.DataBindings.Add(myBinding);
}

private void DecimalToCurrency(object sender, 
   ConvertEventArgs cevent)
{
   /* This method is the Format event handler. Whenever the 
   control displays a new value, the value is converted from 
   its native Decimal type to a string. The ToString method 
   then formats the value as a Currency, by using the 
   formatting character "c". */
   cevent.Value = ((decimal) cevent.Value).ToString("c");
}

private void CurrencyToDecimal(object sender, 
   ConvertEventArgs cevent)
{   
   /* This method is the Parse event handler. The Parse event 
   occurs whenever the displayed value changes. The static 
   Parse method of the Decimal structure converts the 
   string back to its native Decimal type. */
   cevent.Value = Decimal.Parse(cevent.Value.ToString(),
   NumberStyles.Currency, null);
}

Private Sub BindTextBoxControl()
   Dim myDataSet As New DataSet()
   ' Insert code to populate the DataSet with tables, columns, and data.

   ' Creates a new Binding object. 
   Dim myBinding As New Binding("Text", myDataSet, _
   "customers.custToOrders.OrderAmount")
   
   ' Adds event delegates for the Parse and Format events.
   AddHandler myBinding.Parse, AddressOf CurrencyToDecimal
   AddHandler myBinding.Format, AddressOf DecimalToCurrency
     
   ' Adds the new Binding to the BindingsCollection.
   text1.DataBindings.Add(myBinding)
End Sub 
    
Private Sub DecimalToCurrency(sender As Object, _
   cevent As ConvertEventArgs)
   ' This method is the Format event handler. Whenever the
   ' control displays a new value, the value is converted from
   ' its native Decimal type to a string. The ToString method
   ' then formats the value as a Currency, by using the
   ' formatting character "c". 
   cevent.Value = CDec(cevent.Value).ToString("c")
End Sub 
    
Private Sub CurrencyToDecimal(sender As Object, _
cevent As ConvertEventArgs)
   ' This method is the Parse event handler. The Parse event
   ' occurs whenever the displayed value changes. The static
   ' Parse method of the Decimal structure converts the 
   ' string back to its native Decimal type. 
   cevent.Value = Decimal.Parse(cevent.Value.ToString(), _
   NumberStyles.Currency, nothing)
   End Sub

備註

簡單的資料綁定是透過在 . 中加入 Binding 物件 BindingsCollection來完成的。 任何繼承自類別的Control物件都可以透過該DataBindings屬性存取。BindingsCollection 有關支援資料綁定的 Windows 控制項清單，請參見該 Binding 類別。

屬性

名稱	Description
Count	取得集合中總裝訂數量。
IsReadOnly	會獲得一個值，表示該集合是否為唯讀。 (繼承來源 BaseCollection)
IsSynchronized	會取得一個值，表示存取是否 ICollection 同步。 (繼承來源 BaseCollection)
Item[Int32]	在指定的索引處得到 。Binding
List	將綁定放在集合裡作為物件。
SyncRoot	取得一個物件，可用來同步存取 BaseCollection。 (繼承來源 BaseCollection)

方法

名稱	Description
Add(Binding)	將指定的綁定加入集合。
AddCore(Binding)	為收藏增添 a Binding 。
Clear()	清除束縛物品的集合。
ClearCore()	清除任何成員的收藏。
CopyTo(Array, Int32)	將目前一維Array中的所有元素從指定的目的Array索引開始，複製到指定的一維Array。 (繼承來源 BaseCollection)
GetEnumerator()	取得能夠遍歷集合成員的物件。 (繼承來源 BaseCollection)
OnCollectionChanged(CollectionChangeEventArgs)	引發 CollectionChanged 事件。
OnCollectionChanging(CollectionChangeEventArgs)	引發 CollectionChanging 事件。
Remove(Binding)	從集合中刪除指定的綁定。
RemoveAt(Int32)	在指定索引處刪除集合中的綁定。
RemoveCore(Binding)	將指定的 Binding 資料從集合中移除。
ShouldSerializeMyAll()	會得到一個值，指示該集合是否應該序列化。

事件

名稱	Description
CollectionChanged	發生於集合已變更時。
CollectionChanging	當收款即將變動時，會發生這種情況。

另請參閱

• CurrencyManager