ListControl

Namespace: Wisej.Web

Assembly: Wisej.Framework (4.1.0.0)

• Control
  • ListControl

Provides a common implementation of members for the ListBox and ComboBox classes.

C#

public class ListControl : Control, IValidation, IModified

VB.NET

Public Class ListControl
    Inherits Control
    Implements IValidation, IModified

Properties

AllowHtml

Boolean: Returns or sets a value indicating that the control can display HTML in the Text property. (Default: False)

AllowSelection

Boolean: Returns a value indicating whether the list enables selection of list items.

BorderStyle

BorderStyle: Returns or sets the type of border that is drawn around the ListControl. (Default: Solid)

DataSource

Object: Returns or sets the data source for this ListControl. (Default: null)

Throws:

• ArgumentException The assigned value does not implement the IList or IListSource interfaces.

DisplayMember

String: Returns or sets the property to display for this ListControl. (Default: "")

FormatInfo

IFormatProvider: Returns or sets the IFormatProvider that provides custom formatting behavior. (Default: null)

FormatString

String: Returns or sets the format-specifier characters that indicate how a value is to be displayed. (Default: "")

FormattingEnabled

Boolean: Returns or sets whether formatting is applied to the DisplayMember property of the ListControl. (Default: False)

IconMember

String: Returns or sets the property to use as the icon for the items in the ListControl. (Default: "")

Invalid

Boolean: Returns or sets a value that indicates that the control is invalid.

InvalidMessage

String: Returns or sets the invalid message that is shown in the invalid tooltip. (Default: "")

Modified

Boolean: Returns or sets a value that indicates that the control has been modified by the user since the control was created or its contents were last set.

PrefetchItems

Int32: Returns or sets the number of items to prefetch outside of the visible area when VirtualScroll is set to true. The default is 0 (disabled). (Default: 0)

SelectedIndex

Int32: When overridden in a derived class, gets or sets the zero-based index of the currently selected item.

SelectedValue

Object: Returns or sets the value of the member property specified by the ValueMember property. (Default: null)

Throws:

• InvalidOperationException The assigned value is null or the empty string ("").

ShowToolTips

Boolean: Returns or sets whether to show tooltips (set using ToolTipMember) for the list items. (Default: False)

ToolTipMember

String: Returns or sets the property to use as the tooltip for the items in the ListControl, when the property ShowToolTips is set to true. (Default: "")

ValueMember

String: Returns or sets the property to use as the actual value for the items in the ListControl. (Default: "")

Throws:

• ArgumentException The specified property cannot be found on the object specified by the DataSource property.

VirtualScroll

Boolean: Enables or disables virtual scrolling for the ListControl. When virtual scrolling is enabled, only the visible items are rendered in the browser allowing the ListControl to host virtually unlimited items without any performance loss. (Default: False)

When VirtualScroll is set to true, all the items must be of the same height, limiting the more flexible HTML rendering available when VirtualScroll is off (default).

Setting the property PrefetchItems to a value greater than 0 allows the virtual view to prefetch the specified number of items outside of the visible area to enable smoother scrolling. Throws:

• InvalidOperationException Horizontal orientation is not supported with virtual scrolling.

Methods

Append(data)

Populates the ListControl from the data appending the items to the existing items.

Parameter	Type	Description
data	Object	The object that contains data for the ListControl to display.

Returns: Int32. Numbers of items appended.

Use this method to fill a ListControl without binding it to the data source.

Dispose(disposing)

Dispose the control.

Parameter	Type	Description
disposing	Boolean	true when this method is called by the application rather than a finalizer.

Fill(data)

Populates the ListControl from the data .

Parameter	Type	Description
data	Object	The object that contains data for the ListControl to display.

Returns: Int32. Numbers of items added.

Use this method to fill a ListControl without binding it to the data source.

FilterItemOnProperty(item)

Retrieves the current value of the ListControl item, if it is a property of an object, given the item.

Parameter	Type	Description
item	Object	The object the ListControl item is bound to.

Returns: Object. The filtered object.

FilterItemOnProperty(item, field)

Returns the current value of the ListControl item, if it is a property of an object given the item and the property name.

Parameter	Type	Description
item	Object	The object the ListControl item is bound to.
field	String	The property name of the item the ListControl is bound to.

Returns: Object. The filtered object.

GetItemIcon(item)

Returns the icon object, either an instance of Image or a String representing the icon name or URL, of the specified item.

Parameter	Type	Description
item	Object	The object from which to get the icon to display for the list item.

Returns: Object. If the IconMember property is not specified, the value returned by GetItemIcon is null. Otherwise, the method returns the object value of the member specified in the IconMember property for the object specified in the item parameter.

GetItemText(item)

Returns the text representation of the specified item.

Parameter	Type	Description
item	Object	The object from which to get the contents to display.

Returns: String. If the DisplayMember property is not specified, the value returned by GetItemText is the value of the item's ToString method. Otherwise, the method returns the string value of the member specified in the DisplayMember property for the object specified in the item parameter.

GetItemToolTip(item)

Returns the tooltip text related to the object.

Parameter	Type	Description
item	Object	The object from which to get the tooltip text to display for the list item.

Returns: String. If the ToolTipMember property is not specified, the value returned by GetItemToolTip is null. Otherwise, the method returns the value of the member specified in the ToolTipMember property for the object specified in the item parameter.

GetItemValue(item)

Returns the value of the member property specified by the ValueMember property.

Parameter	Type	Description
item	Object	The object from which to get the value of the list item.

Returns: Object. If the ValueMember property is not specified, the value returned by GetItemValue is null. Otherwise, the method returns the value of the member specified in the ValueMember property for the object specified in the item parameter.

IsInputKey(keyData)

Handles special input keys, such as PAGE UP, PAGE DOWN, HOME, END, and so on.

Parameter	Type	Description
keyData	Keys	One of the values of Keys.

Returns: Boolean. true if the keyData parameter specifies the End, Home, PageUp, or PageDown key; false if the keyData parameter specifies Alt.

OnBindingContextChanged(e)

Fires the BindingContextChanged event.

Parameter	Type	Description
e	EventArgs	A EventArgs that contains the event data.

OnDataSourceChanged(e)

Fires the DataSourceChanged event.

Parameter	Type	Description
e	EventArgs	A EventArgs that contains the event data.

OnDisplayMemberChanged(e)

Fires the DisplayMemberChanged event.

Parameter	Type	Description
e	EventArgs	A EventArgs that contains the event data.

OnFormat(e)

Raises the Format event.

Parameter	Type	Description
e	ListControlConvertEventArgs	A ListControlConvertEventArgs that contains the event data.

OnFormatInfoChanged(e)

Fires the FormatInfoChanged event.

Parameter	Type	Description
e	EventArgs	A EventArgs that contains the event data.

OnFormatStringChanged(e)

Fires the FormatStringChanged event.

Parameter	Type	Description
e	EventArgs	A EventArgs that contains the event data.

OnFormattingEnabledChanged(e)

Fires the FormattingEnabledChanged event.

Parameter	Type	Description
e	EventArgs	A EventArgs that contains the event data.

OnIconMemberChanged(e)

Fires the IconMemberChanged event.

Parameter	Type	Description
e	EventArgs	A EventArgs that contains the event data.

OnModifiedChanged(e)

Fires the ModifiedChanged event.

Parameter	Type	Description
e	EventArgs	A EventArgs that contains the event data.

OnSelectedIndexChanged(e)

Fires the SelectedValueChanged event.

Parameter	Type	Description
e	EventArgs	A EventArgs that contains the event data.

OnSelectedValueChanged(e)

Fires the SelectedValueChanged event.

Parameter	Type	Description
e	EventArgs	A EventArgs that contains the event data.

OnToolTipMemberChanged(e)

Fires the ToolTipMemberChanged event.

Parameter	Type	Description
e	EventArgs	A EventArgs that contains the event data.

OnValidating(e)

Fires the Validating event.

Parameter	Type	Description
e	CancelEventArgs	A CancelEventArgs that contains the event data.

OnValueMemberChanged(e)

Fires the ValueMemberChanged event.

Parameter	Type	Description
e	EventArgs	A EventArgs that contains the event data.

OnWebRender(config)

Renders the client component.

Parameter	Type	Description
config	Object	Dynamic configuration object.

RefreshItem(index)

When overridden in a derived class, resynchronizes the data of the object at the specified index with the contents of the data source.

Parameter	Type	Description
index	Int32	The zero-based index of the item whose data to refresh.

RefreshItems()

When overridden in a derived class, resynchronizes the item data with the contents of the data source.

RenderItem(item)

Renders the text representation of the specified item. If AllowHtml is set to false, the text is encoded.

Parameter	Type	Description
item	Object	The object from which to get the contents to display.

Returns: Object. If the DisplayMember property is not specified, the value returned by GetItemText is the value of the item's ToString method. Otherwise, the method returns the string value of the member specified in the DisplayMember property for the object specified in the item parameter.

SetItemCore(index, value)

When overridden in a derived class, sets the object with the specified index in the derived class.

Parameter	Type	Description
index	Int32	The array index of the object.
value	Object	The object.

SetItemsCore(items)

When overridden in a derived class, sets the specified array of objects in a collection in the derived class.

Parameter	Type	Description
items	IList	An array of items.

Events

DataSourceChanged

EventHandler Fired when the DataSource changes.

DisplayMemberChanged

EventHandler Fired when the DisplayMember property changes.

Format

ListControlConvertEventHandler Fired when the control is bound to a data value.

FormatInfoChanged

EventHandler Fired when the value of the FormatInfo property changes.

FormatStringChanged

EventHandler Fired when value of the FormatString property changes.

FormattingEnabledChanged

EventHandler Fired when the value of the FormattingEnabled property changes.

IconMemberChanged

EventHandler Fired when the IconMember property changes.

ModifiedChanged

EventHandler Fired when the value of the Modified property has changed.

SelectedValueChanged

EventHandler Fired when the SelectedValue property changes.

ToolTipMemberChanged

EventHandler Fired when the ToolTipMember property changes.

ValueMemberChanged

EventHandler Fired when the ValueMember property changes.

Inherited By

Name	Description
CheckedListBox	Displays a ListBox in which a check box is displayed to the left of each item.
ComboBox	Represents a combo box control.
ListBox	Represents a control to display a list of items.
DataGridViewComboBoxEditingControl	Represents a ComboBox control that can be hosted in a DataGridViewComboBoxCell.
ListViewComboBox	The TreeViewComboBox control represents a UserComboBox control with a ListView as the drop down panel.
TreeViewComboBox	The TreeViewComboBox control represents a UserComboBox control with a TreeView as the drop down panel.
UserComboBox	The UserComboBox control represents a ComboBox control with a custom panel that drops down when the user clicks the down arrow.

Implements

Name	Description
IUserData	Provides access to the UserData and Tag properties associated to the component implementing this interface.
IBindableComponent	Bindable components implement this interface.
IDropTarget	Controls that support drag & drop operations implement this interface.
IModified	Provides access to the Modified property and ModifiedChanged event for controls that implement this interface.
IValidation	Provides access to the validation events and properties property for controls that support validation.
IWisejComponent	All wisej components implement this interface.
IWisejControl	All wisej controls derived from the Control class must implement this interface.
IWisejSerializable	Allows an object to serialize itself.