如何:在代码中创建绑定
此示例演示如何在代码中创建和设置 Binding。
示例
FrameworkElement 类和 FrameworkContentElement 类都公开 SetBinding 方法。 如果您要绑定一个继承这些类之一的元素,则可以直接调用 SetBinding 方法。
下面的示例创建一个名为 MyData 的类,该类包含一个名为 MyDataProperty 的属性。
Public Class MyData
Implements INotifyPropertyChanged
' Events
Public Event PropertyChanged As PropertyChangedEventHandler _
Implements INotifyPropertyChanged.PropertyChanged
' Methods
Public Sub New()
End Sub
Public Sub New(ByVal dateTime As DateTime)
Me.MyDataProperty = ("Last bound time was " & dateTime.ToLongTimeString)
End Sub
Private Sub OnPropertyChanged(ByVal info As String)
RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(info))
End Sub
' Properties
Public Property MyDataProperty As String
Get
Return Me._myDataProperty
End Get
Set(ByVal value As String)
Me._myDataProperty = value
Me.OnPropertyChanged("MyDataProperty")
End Set
End Property
' Fields
Private _myDataProperty As String
End Class
public class MyData : INotifyPropertyChanged
{
private string myDataProperty;
public MyData() { }
public MyData(DateTime dateTime)
{
myDataProperty = "Last bound time was " + dateTime.ToLongTimeString();
}
public String MyDataProperty
{
get { return myDataProperty; }
set
{
myDataProperty = value;
OnPropertyChanged("MyDataProperty");
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string info)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(info));
}
}
}
下面的示例演示如何创建绑定对象以设置绑定源。 该示例使用 SetBinding 将 myText(它是一个 TextBlock 控件)的 Text 属性绑定到 MyDataProperty。
Dim data1 As New MyData(DateTime.Now)
Dim binding1 As New Binding("MyDataProperty")
binding1.Source = data1
Me.myText.SetBinding(TextBlock.TextProperty, binding1)
//make a new source
MyData myDataObject = new MyData(DateTime.Now);
Binding myBinding = new Binding("MyDataProperty");
myBinding.Source = myDataObject;
myText.SetBinding(TextBlock.TextProperty, myBinding);
有关完整代码示例,请参见Creating a Binding in Code Sample。
您可以使用 BindingOperations 类的 SetBinding 静态方法,而不是调用 SetBinding。 下面的示例调用 BindingOperations.SetBinding(而不是 FrameworkElement.SetBinding),以将 myText 绑定到 myDataProperty。
Dim myDataObject As New MyData(DateTime.Now)
Dim myBinding As New Binding("MyDataProperty")
myBinding.Source = myDataObject
BindingOperations.SetBinding(myText, TextBlock.TextProperty, myBinding)
//make a new source
MyData myDataObject = new MyData(DateTime.Now);
Binding myBinding = new Binding("MyDataProperty");
myBinding.Source = myDataObject;
BindingOperations.SetBinding(myText, TextBlock.TextProperty, myBinding);