DataBinding(String, Type, String) 建構函式

定義

命名空間:

System.Web.UI

組件:

System.Web.dll

初始化 DataBinding 類別的新執行個體。

public:
 DataBinding(System::String ^ propertyName, Type ^ propertyType, System::String ^ expression);

public DataBinding (string propertyName, Type propertyType, string expression);

new System.Web.UI.DataBinding : string * Type * string -> System.Web.UI.DataBinding

Public Sub New (propertyName As String, propertyType As Type, expression As String)

參數

propertyName

String

資料要繫結至的屬性。

propertyType

Type

資料要繫結至的 .NET Framework 屬性型別。

expression

String

要評估的資料繫結運算式。

範例

下列程式碼範例會 DataBinding 建立 物件，並將它設定為 與 控制項集合 DataBindingCollection 中的現有物件相等，其 propertyName 具有 值為 Text 的參數。 如果集合包含 DataBinding 值為 Text 的物件 propertyName ，則此程式碼會傳回物件的 Expression 屬性值。 如果沒有這類物件，它會傳回空字串 (「」) 。

// Create a Text property with accessors that obtain 
// the property value from and set the property value
// to the Text key in the DataBindingCollection class.
public string Text
{
    get
    {
        DataBinding myBinding = DataBindings["Text"];
        if (myBinding != null)
        {
            return myBinding.Expression;
        }
        return String.Empty;
    }
    set
    {

        if ((value == null) || (value.Length == 0))
        {
            DataBindings.Remove("Text");
        }
        else
        {

            DataBinding binding = DataBindings["Text"];

            if (binding == null)
            {
                binding = new DataBinding("Text", typeof(string), value);
            }
            else
            {
                binding.Expression = value;
            }
            // Call the DataBinding constructor, then add
            // the initialized DataBinding object to the 
            // DataBindingCollection for this custom designer.
            DataBinding binding1 = (DataBinding)DataBindings.SyncRoot;
            DataBindings.Add(binding);
            DataBindings.Add(binding1);
        }
        PropertyChanged("Text");
    }
}

' Create a Text property with accessors that obtain 
' the property value from and set the property value
' to the Text key in the DataBindingCollection class.

Public Property [Text]() As String
    Get
        Dim myBinding As DataBinding = DataBindings("Text")
        If Not (myBinding Is Nothing) Then
            Return myBinding.Expression
        End If
        Return String.Empty
    End Get
    Set(ByVal value As String)

        If value Is Nothing OrElse value.Length = 0 Then
            DataBindings.Remove("Text")
        Else

            Dim binding As DataBinding = DataBindings("Text")

            If binding Is Nothing Then
                binding = New DataBinding("Text", GetType(String), value)
            Else
                binding.Expression = value
            End If
            ' Call the DataBinding constructor, then add
            ' the initialized DataBinding object to the 
            ' DataBindingCollection for this custom designer.
            Dim binding1 As DataBinding = CType(DataBindings.SyncRoot, DataBinding)
            DataBindings.Add(binding)
            DataBindings.Add(binding1)
        End If
        PropertyChanged("Text")
    End Set
End Property

另請參閱

• DataBinder