Control.DataBindings Vlastnost
Definice
Důležité
Některé informace platí pro předběžně vydaný produkt, který se může zásadně změnit, než ho výrobce nebo autor vydá. Microsoft neposkytuje žádné záruky, výslovné ani předpokládané, týkající se zde uváděných informací.
Získá datové vazby pro ovládací prvek.
public:
property System::Windows::Forms::ControlBindingsCollection ^ DataBindings { System::Windows::Forms::ControlBindingsCollection ^ get(); };
public System.Windows.Forms.ControlBindingsCollection DataBindings { get; }
member this.DataBindings : System.Windows.Forms.ControlBindingsCollection
Public ReadOnly Property DataBindings As ControlBindingsCollection
Hodnota vlastnosti
A ControlBindingsCollection , který obsahuje Binding objekty ovládacího prvku.
Implementuje
Příklady
Následující příklad kódu přidá Binding objekty do ControlBindingsCollection pěti ovládacích prvků: čtyři TextBox ovládací prvky a DateTimePicker ovládací prvek. Tato ControlBindingsCollection vlastnost je přístupná prostřednictvím DataBindings vlastnosti Control třídy.
void 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( gcnew Binding( "Text",ds,"customers.custName" ) );
textBox2->DataBindings->Add( gcnew 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( gcnew 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. */
Binding^ b = gcnew Binding( "Text",ds,"customers.custToOrders.OrderAmount" );
b->Parse += gcnew ConvertEventHandler( this, &Form1::CurrencyStringToDecimal );
b->Format += gcnew ConvertEventHandler( this, &Form1::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" );
BindingManagerBase^ bmText = this->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() );
// Print the count of managed objects, which is 1.
Console::WriteLine( bmText->Count );
// Get the BindingManagerBase for the Customers table.
bmCustomers = this->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() );
Console::WriteLine( bmCustomers->Count );
/* Get the BindingManagerBase for the Orders of the current
customer using a navigation path: TableName.RelationName. */
bmOrders = this->BindingContext[ds, "customers.CustToOrders"];
}
protected void 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. */
Binding b = new Binding
("Text", ds, "customers.custToOrders.OrderAmount");
b.Parse += new ConvertEventHandler(CurrencyStringToDecimal);
b.Format += new ConvertEventHandler(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");
BindingManagerBase bmText = this.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 = this.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 = this.BindingContext[ds, "customers.CustToOrders"];
}
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
Poznámky
DataBindings Použijte vlastnost pro přístup k ControlBindingsCollection. Přidáním Binding objektů do kolekce můžete svázat libovolnou vlastnost ovládacího prvku s vlastností objektu.