BindingSource Class
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BindingSource Class

 

Encapsulates the data source for a form.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

System.Object
  System.MarshalByRefObject
    System.ComponentModel.Component
      System.Windows.Forms.BindingSource

[ComplexBindingPropertiesAttribute("DataSource", "DataMember")]
public class BindingSource : Component, IBindingListView, IBindingList, 
	IList, ICollection, IEnumerable, ITypedList, ICancelAddNew, 
	ISupportInitializeNotification, ISupportInitialize, ICurrencyManagerProvider

NameDescription
System_CAPS_pubmethodBindingSource()

Initializes a new instance of the BindingSource class to the default property values.

System_CAPS_pubmethodBindingSource(IContainer)

Initializes a new instance of the BindingSource class and adds the BindingSource to the specified container.

System_CAPS_pubmethodBindingSource(Object, String)

Initializes a new instance of the BindingSource class with the specified data source and data member.

NameDescription
System_CAPS_pubpropertyAllowEdit

Gets a value indicating whether items in the underlying list can be edited.

System_CAPS_pubpropertyAllowNew

Gets or sets a value indicating whether the AddNew method can be used to add items to the list.

System_CAPS_pubpropertyAllowRemove

Gets a value indicating whether items can be removed from the underlying list.

System_CAPS_protpropertyCanRaiseEvents

Gets a value indicating whether the component can raise an event.(Inherited from Component.)

System_CAPS_pubpropertyContainer

Gets the IContainer that contains the Component.(Inherited from Component.)

System_CAPS_pubpropertyCount

Gets the total number of items in the underlying list, taking the current Filter value into consideration.

System_CAPS_pubpropertyCurrencyManager

Gets the currency manager associated with this BindingSource.

System_CAPS_pubpropertyCurrent

Gets the current item in the list.

System_CAPS_pubpropertyDataMember

Gets or sets the specific list in the data source to which the connector currently binds to.

System_CAPS_pubpropertyDataSource

Gets or sets the data source that the connector binds to.

System_CAPS_protpropertyDesignMode

Gets a value that indicates whether the Component is currently in design mode.(Inherited from Component.)

System_CAPS_protpropertyEvents

Gets the list of event handlers that are attached to this Component.(Inherited from Component.)

System_CAPS_pubpropertyFilter

Gets or sets the expression used to filter which rows are viewed.

System_CAPS_pubpropertyIsBindingSuspended

Gets a value indicating whether the list binding is suspended.

System_CAPS_pubpropertyIsFixedSize

Gets a value indicating whether the underlying list has a fixed size.

System_CAPS_pubpropertyIsReadOnly

Gets a value indicating whether the underlying list is read-only.

System_CAPS_pubpropertyIsSorted

Gets a value indicating whether the items in the underlying list are sorted.

System_CAPS_pubpropertyIsSynchronized

Gets a value indicating whether access to the collection is synchronized (thread safe).

System_CAPS_pubpropertyItem[Int32]

Gets or sets the list element at the specified index.

System_CAPS_pubpropertyList

Gets the list that the connector is bound to.

System_CAPS_pubpropertyPosition

Gets or sets the index of the current item in the underlying list.

System_CAPS_pubpropertyRaiseListChangedEvents

Gets or sets a value indicating whether ListChanged events should be raised.

System_CAPS_pubpropertySite

Gets or sets the ISite of the Component.(Inherited from Component.)

System_CAPS_pubpropertySort

Gets or sets the column names used for sorting, and the sort order for viewing the rows in the data source.

System_CAPS_pubpropertySortDescriptions

Gets the collection of sort descriptions applied to the data source.

System_CAPS_pubpropertySortDirection

Gets the direction the items in the list are sorted.

System_CAPS_pubpropertySortProperty

This API supports the product infrastructure and is not intended to be used directly from your code. Gets the PropertyDescriptor that is being used for sorting the list.

System_CAPS_pubpropertySupportsAdvancedSorting

Gets a value indicating whether the data source supports multi-column sorting.

System_CAPS_pubpropertySupportsChangeNotification

Gets a value indicating whether the data source supports change notification.

System_CAPS_pubpropertySupportsFiltering

Gets a value indicating whether the data source supports filtering.

System_CAPS_pubpropertySupportsSearching

Gets a value indicating whether the data source supports searching with the Find method.

System_CAPS_pubpropertySupportsSorting

Gets a value indicating whether the data source supports sorting.

System_CAPS_pubpropertySyncRoot

Gets an object that can be used to synchronize access to the underlying list.

NameDescription
System_CAPS_pubmethodAdd(Object)

Adds an existing item to the internal list.

System_CAPS_pubmethodAddNew()

Adds a new item to the underlying list.

System_CAPS_pubmethodApplySort(ListSortDescriptionCollection)

Sorts the data source with the specified sort descriptions.

System_CAPS_pubmethodApplySort(PropertyDescriptor, ListSortDirection)

Sorts the data source using the specified property descriptor and sort direction.

System_CAPS_pubmethodCancelEdit()

Cancels the current edit operation.

System_CAPS_pubmethodClear()

Removes all elements from the list.

System_CAPS_pubmethodContains(Object)

Determines whether an object is an item in the list.

System_CAPS_pubmethodCopyTo(Array, Int32)

Copies the contents of the List to the specified array, starting at the specified index value.

System_CAPS_pubmethodCreateObjRef(Type)

Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object.(Inherited from MarshalByRefObject.)

System_CAPS_pubmethodDispose()

Releases all resources used by the Component.(Inherited from Component.)

System_CAPS_protmethodDispose(Boolean)

Releases the unmanaged resources used by the BindingSource and optionally releases the managed resources. (Overrides Component.Dispose(Boolean).)

System_CAPS_pubmethodEndEdit()

Applies pending changes to the underlying data source.

System_CAPS_pubmethodEquals(Object)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_protmethodFinalize()

Releases unmanaged resources and performs other cleanup operations before the Component is reclaimed by garbage collection.(Inherited from Component.)

System_CAPS_pubmethodFind(PropertyDescriptor, Object)

Searches for the index of the item that has the given property descriptor.

System_CAPS_pubmethodFind(String, Object)

Returns the index of the item in the list with the specified property name and value.

System_CAPS_pubmethodGetEnumerator()

Retrieves an enumerator for the List.

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetItemProperties(PropertyDescriptor[])

Retrieves an array of PropertyDescriptor objects representing the bindable properties of the data source list type.

System_CAPS_pubmethodGetLifetimeService()

Retrieves the current lifetime service object that controls the lifetime policy for this instance.(Inherited from MarshalByRefObject.)

System_CAPS_pubmethodGetListName(PropertyDescriptor[])

Gets the name of the list supplying data for the binding.

System_CAPS_pubmethodGetRelatedCurrencyManager(String)

Gets the related currency manager for the specified data member.

System_CAPS_protmethodGetService(Type)

Returns an object that represents a service provided by the Component or by its Container.(Inherited from Component.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodIndexOf(Object)

Searches for the specified object and returns the index of the first occurrence within the entire list.

System_CAPS_pubmethodInitializeLifetimeService()

Obtains a lifetime service object to control the lifetime policy for this instance.(Inherited from MarshalByRefObject.)

System_CAPS_pubmethodInsert(Int32, Object)

Inserts an item into the list at the specified index.

System_CAPS_protmethodMemberwiseClone()

Creates a shallow copy of the current Object.(Inherited from Object.)

System_CAPS_protmethodMemberwiseClone(Boolean)

Creates a shallow copy of the current MarshalByRefObject object.(Inherited from MarshalByRefObject.)

System_CAPS_pubmethodMoveFirst()

Moves to the first item in the list.

System_CAPS_pubmethodMoveLast()

Moves to the last item in the list.

System_CAPS_pubmethodMoveNext()

Moves to the next item in the list.

System_CAPS_pubmethodMovePrevious()

Moves to the previous item in the list.

System_CAPS_protmethodOnAddingNew(AddingNewEventArgs)

Raises the AddingNew event.

System_CAPS_protmethodOnBindingComplete(BindingCompleteEventArgs)

Raises the BindingComplete event.

System_CAPS_protmethodOnCurrentChanged(EventArgs)

Raises the CurrentChanged event.

System_CAPS_protmethodOnCurrentItemChanged(EventArgs)

Raises the CurrentItemChanged event.

System_CAPS_protmethodOnDataError(BindingManagerDataErrorEventArgs)

Raises the DataError event.

System_CAPS_protmethodOnDataMemberChanged(EventArgs)

Raises the DataMemberChanged event.

System_CAPS_protmethodOnDataSourceChanged(EventArgs)

Raises the DataSourceChanged event.

System_CAPS_protmethodOnListChanged(ListChangedEventArgs)

Raises the ListChanged event.

System_CAPS_protmethodOnPositionChanged(EventArgs)

Raises the PositionChanged event.

System_CAPS_pubmethodRemove(Object)

Removes the specified item from the list.

System_CAPS_pubmethodRemoveAt(Int32)

Removes the item at the specified index in the list.

System_CAPS_pubmethodRemoveCurrent()

Removes the current item from the list.

System_CAPS_pubmethodRemoveFilter()

Removes the filter associated with the BindingSource.

System_CAPS_pubmethodRemoveSort()

Removes the sort associated with the BindingSource.

System_CAPS_pubmethodResetAllowNew()

This API supports the product infrastructure and is not intended to be used directly from your code. Reinitializes the AllowNew property.

System_CAPS_pubmethodResetBindings(Boolean)

Causes a control bound to the BindingSource to reread all the items in the list and refresh their displayed values.

System_CAPS_pubmethodResetCurrentItem()

Causes a control bound to the BindingSource to reread the currently selected item and refresh its displayed value.

System_CAPS_pubmethodResetItem(Int32)

Causes a control bound to the BindingSource to reread the item at the specified index, and refresh its displayed value.

System_CAPS_pubmethodResumeBinding()

Resumes data binding.

System_CAPS_pubmethodSuspendBinding()

Suspends data binding to prevent changes from updating the bound data source.

System_CAPS_pubmethodToString()

Returns a String containing the name of the Component, if any. This method should not be overridden.(Inherited from Component.)

NameDescription
System_CAPS_pubeventAddingNew

Occurs before an item is added to the underlying list.

System_CAPS_pubeventBindingComplete

Occurs when all the clients have been bound to this BindingSource.

System_CAPS_pubeventCurrentChanged

Occurs when the currently bound item changes.

System_CAPS_pubeventCurrentItemChanged

Occurs when a property value of the Current property has changed.

System_CAPS_pubeventDataError

Occurs when a currency-related exception is silently handled by the BindingSource.

System_CAPS_pubeventDataMemberChanged

Occurs when the DataMember property value has changed.

System_CAPS_pubeventDataSourceChanged

Occurs when the DataSource property value has changed.

System_CAPS_pubeventDisposed

Occurs when the component is disposed by a call to the Dispose method. (Inherited from Component.)

System_CAPS_pubeventListChanged

Occurs when the underlying list changes or an item in the list changes.

System_CAPS_pubeventPositionChanged

Occurs after the value of the Position property has changed.

NameDescription
System_CAPS_pubinterfaceSystem_CAPS_priveventISupportInitializeNotification.Initialized

Occurs when the BindingSource is initialized.

System_CAPS_pubinterfaceSystem_CAPS_privmethodIBindingList.AddIndex(PropertyDescriptor)

Adds the PropertyDescriptor to the indexes used for searching.

System_CAPS_pubinterfaceSystem_CAPS_privmethodIBindingList.RemoveIndex(PropertyDescriptor)

Removes the System.ComponentModel.PropertyDescriptor from the indexes used for searching.

System_CAPS_pubinterfaceSystem_CAPS_privmethodICancelAddNew.CancelNew(Int32)

Discards a pending new item from the collection.

System_CAPS_pubinterfaceSystem_CAPS_privmethodICancelAddNew.EndNew(Int32)

Commits a pending new item to the collection.

System_CAPS_pubinterfaceSystem_CAPS_privmethodISupportInitialize.BeginInit()

Signals the BindingSource that initialization is starting.

System_CAPS_pubinterfaceSystem_CAPS_privmethodISupportInitialize.EndInit()

Signals the BindingSource that initialization is complete.

System_CAPS_pubinterfaceSystem_CAPS_privpropertyISupportInitializeNotification.IsInitialized

Gets a value indicating whether the BindingSource is initialized.

NameDescription
System_CAPS_pubmethodAsParallel()

Overloaded. Enables parallelization of a query.(Defined by ParallelEnumerable.)

System_CAPS_pubmethodAsQueryable()

Overloaded. Converts an IEnumerable to an IQueryable.(Defined by Queryable.)

System_CAPS_pubmethodCast<TResult>()

Casts the elements of an IEnumerable to the specified type.(Defined by Enumerable.)

System_CAPS_pubmethodOfType<TResult>()

Filters the elements of an IEnumerable based on a specified type.(Defined by Enumerable.)

The BindingSource component serves many purposes. First, it simplifies binding controls on a form to data by providing currency management, change notification, and other services between Windows Forms controls and data sources. This is accomplished by attaching the BindingSource component to your data source using the DataSource property. For complex binding scenarios you can optionally set the DataMember property to a specific column or list in the data source. You then bind controls to the BindingSource. All further interaction with the data is accomplished with calls to the BindingSource component. For examples on how the BindingSource can simplify the binding process, see How to: Bind Windows Forms Controls to DBNull Database Values and How to: Handle Errors and Exceptions that Occur with Databinding. Navigation and updating of the data source is accomplished through methods such as MoveNext, MoveLast, and Remove. Operations such as sorting and filtering are handled through the Sort and Filter properties. For more information on using sorting and filtering with the BindingSource, see How to: Sort and Filter ADO.NET Data with the Windows Forms BindingSource Component.

In addition, the BindingSource component can act as a strongly typed data source. Typically the type of the underlying data source is fixed through one of the following mechanisms:

  • Use the Add method to add an item to the BindingSource component.

  • Set the DataSource property to a list, single object, or type.

Both of these mechanisms create a strongly-typed list. For more information on how to use the BindingSource to bind to a type, see How to: Bind a Windows Forms Control to a Type. You can also use the BindingSource to bind your controls to a factory object. For more information on how to do this, see How to: Bind a Windows Forms Control to a Factory Object.

System_CAPS_noteNote

Because a BindingSource handles both simple and complex data sources, terminology is problematic. Within this class documentation, the term list refers to a data collection within the hosted data source, and item denotes a single element. When discussing functionality associated with complex data sources, the equivalent terms table and row are used.

BindingSource provides members for accessing the underlying data. The current item can be retrieved through the Current property, and the entire list can be retrieved through the List property. Editing operations are supported on the current item through Current and the RemoveCurrent, EndEdit, CancelEdit and Add and AddNew methods. Although currency management is handled automatically for all underlying data source types, this class exposes a number of events, such as CurrentItemChanged and DataSourceChanged, that allow for customization.

Data sources that are bound to a BindingSource component can also be navigated and managed with the BindingNavigator class, which provides a VCR-like user interface (UI) for navigating items within a list. Although BindingNavigator can be bound to any data source, it was designed to integrate with a BindingSource component through its BindingNavigator.BindingSource property.

The default property for the BindingSource class is DataSource. The default event is CurrentChanged.

System_CAPS_cautionCaution

  Many of the members of the BindingSource class operate on the underlying list represented by the List property and simply refer their operation to the underlying list. Therefore, when the BindingSource is bound to a custom implementation of IList, the exact behavior of these members may differ from the behavior described in the class documentation. For example, the RemoveAt method calls IList.RemoveAt. The BindingSource documentation describes the RemoveAt method with the understanding that the RemoveAt method for the underlying IList is correctly implemented.

The following code example demonstrates a ListBox bound to a BindingSource. The BindingSource is bound to a BindingList<T> that contains a list of fonts.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace BindingSourceExamples
{
    public class Form1 : Form
    {
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.Run(new Form1());
        }

        public Form1()
        {
            this.Load += new EventHandler(Form1_Load);
        }

        private TextBox textBox1;
        private Button button1;
        private ListBox listBox1;

        private BindingSource binding1;
        void Form1_Load(object sender, EventArgs e)
        {
            listBox1 = new ListBox();
            textBox1 = new TextBox();
            binding1 = new BindingSource();
            button1 = new Button();
            listBox1.Location = new Point(140, 25);
            listBox1.Size = new Size(123, 160);
            textBox1.Location = new Point(23, 70);
            textBox1.Size = new Size(100, 20);
            textBox1.Text = "Wingdings";
            button1.Location = new Point(23, 25);
            button1.Size = new Size(75, 23);
            button1.Text = "Search";
            button1.Click += new EventHandler(this.button1_Click);
            this.ClientSize = new Size(292, 266);
            this.Controls.Add(this.button1);
            this.Controls.Add(this.textBox1);
            this.Controls.Add(this.listBox1);

            MyFontList fonts = new MyFontList();
            for (int i = 0; i < FontFamily.Families.Length; i++)
            {
                if (FontFamily.Families[i].IsStyleAvailable(FontStyle.Regular))
                    fonts.Add(new Font(FontFamily.Families[i], 11.0F, FontStyle.Regular));
            }
            binding1.DataSource = fonts;
            listBox1.DataSource = binding1;
            listBox1.DisplayMember = "Name";

        }


        private void button1_Click(object sender, EventArgs e)
        {
            if (binding1.SupportsSearching != true)
                MessageBox.Show("Cannot search the list.");
            else
            {
                int foundIndex = binding1.Find("Name", textBox1.Text);
                if (foundIndex > -1)
                    listBox1.SelectedIndex = foundIndex;
                else
                    MessageBox.Show("Font was not found.");
            }
        }
    }

    public class MyFontList : BindingList<Font>
    {

        protected override bool SupportsSearchingCore
        {
            get { return true; }
        }
        protected override int FindCore(PropertyDescriptor prop, object key)
        {
            // Ignore the prop value and search by family name.
            for (int i = 0; i < Count; ++i)
            {
                if (Items[i].FontFamily.Name.ToLower() == ((string)key).ToLower())
                    return i;

            }
            return -1;
        }


    }

}

.NET Framework
Available since 2.0

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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