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

要綁定資料的屬性。

propertyType

Type

就是要綁定資料的屬性的 .NET 類型。

expression

String

要評估的資料綁定表達式。

範例

以下程式碼範例建立一個 DataBinding 物件，並將其設為控制集合中 DataBindingCollection 已有的物件，該物件的 propertyName 參數值為 Text。 若集合包含 DataBinding 一個值為 propertyNameText的物件，此程式碼會 Expression 回傳該物件屬性的值。 若不存在此類物件，則回傳空字串（“”）。

// 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