VB.NET Control.DataBindings属性代码示例

Protected Sub BindControls()
    ' Create two Binding objects for the first two TextBox 
    ' controls. The data-bound property for both controls 
    ' is the Text property. The data source is a DataSet 
    ' (ds). The data member is specified by a navigation 
    ' path in the form : TableName.ColumnName. 
    textBox1.DataBindings.Add _
       (New Binding("Text", ds, "customers.custName"))
    textBox2.DataBindings.Add _
       (New Binding("Text", ds, "customers.custID"))
    
    ' Bind the DateTimePicker control by adding a new Binding. 
    ' The data member of the DateTimePicker is specified by a 
    ' navigation path in the form: TableName.RelationName.ColumnName. 
    DateTimePicker1.DataBindings.Add _
       (New Binding("Value", ds, "customers.CustToOrders.OrderDate"))
    
    ' Create a new Binding using the DataSet and a 
    ' navigation path(TableName.RelationName.ColumnName).
    ' Add event delegates for the Parse and Format events to 
    ' the Binding object, and add the object to the third 
    ' TextBox control's BindingsCollection. The delegates 
    ' must be added before adding the Binding to the 
    ' collection; otherwise, no formatting occurs until 
    ' the Current object of the BindingManagerBase for
    ' the data source changes. 
    Dim b As New Binding("Text", ds, "customers.custToOrders.OrderAmount")
    AddHandler b.Parse, AddressOf CurrencyStringToDecimal
    AddHandler b.Format, AddressOf DecimalToCurrencyString
    textBox3.DataBindings.Add(b)
    
    ' Bind the fourth TextBox to the Value of the 
    ' DateTimePicker control. This demonstrates how one control
    ' can be bound to another.
    textBox4.DataBindings.Add("Text", DateTimePicker1, "Value")
    Dim bmText As BindingManagerBase = Me.BindingContext(DateTimePicker1)
    
    ' Print the Type of the BindingManagerBase, which is 
    ' a PropertyManager because the data source
    ' returns only a single property value. 
    Console.WriteLine(bmText.GetType().ToString())
    ' Print the count of managed objects, which is 1.
    Console.WriteLine(bmText.Count)
    
    ' Get the BindingManagerBase for the Customers table. 
    bmCustomers = Me.BindingContext(ds, "Customers")
    ' Print the Type and count of the BindingManagerBase.
    ' Because the data source inherits from IBindingList,
    ' it is a RelatedCurrencyManager (derived from CurrencyManager). 
    Console.WriteLine(bmCustomers.GetType().ToString())
    Console.WriteLine(bmCustomers.Count)
    
    ' Get the BindingManagerBase for the Orders of the current
    ' customer using a navigation path: TableName.RelationName. 
    bmOrders = Me.BindingContext(ds, "customers.CustToOrders")
End Sub