HierarchicalDataSourceControl Class
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Provides a base class for data source controls that represent hierarchical data.
Assembly: System.Web (in System.Web.dll)
System.Web.UI.Control
System.Web.UI.HierarchicalDataSourceControl
System.Web.UI.WebControls.SiteMapDataSource
System.Web.UI.WebControls.XmlDataSource
Name | Description | |
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![]() | HierarchicalDataSourceControl() | Initializes a new instance of the HierarchicalDataSourceControl class. |
Name | Description | |
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![]() | Adapter | Gets the browser-specific adapter for the control.(Inherited from Control.) |
![]() | AppRelativeTemplateSourceDirectory | Gets or sets the application-relative virtual directory of the Page or UserControl object that contains this control.(Inherited from Control.) |
![]() | BindingContainer | This API supports the product infrastructure and is not intended to be used directly from your code. Gets the control that contains this control's data binding.(Inherited from Control.) |
![]() | ChildControlsCreated | Gets a value that indicates whether the server control's child controls have been created.(Inherited from Control.) |
![]() | ClientID | Gets the server control identifier generated by ASP.NET.(Overrides Control.ClientID.) |
![]() | ClientIDMode | This property is not used for data source controls.(Overrides Control.ClientIDMode.) |
![]() | ClientIDSeparator | |
![]() | Context | Gets the HttpContext object associated with the server control for the current Web request.(Inherited from Control.) |
![]() | Controls | Gets a ControlCollection object that represents the child controls for a specified server control in the UI hierarchy.(Overrides Control.Controls.) |
![]() | DataItemContainer | Gets a reference to the naming container if the naming container implements IDataItemContainer.(Inherited from Control.) |
![]() | DataKeysContainer | Gets a reference to the naming container if the naming container implements IDataKeysControl.(Inherited from Control.) |
![]() | DesignMode | Gets a value indicating whether a control is being used on a design surface.(Inherited from Control.) |
![]() | EnableTheming | Gets a value indicating whether this control supports themes.(Overrides Control.EnableTheming.) |
![]() | EnableViewState | Gets or sets a value indicating whether the server control persists its view state, and the view state of any child controls it contains, to the requesting client.(Inherited from Control.) |
![]() | Events | Gets a list of event handler delegates for the control. This property is read-only.(Inherited from Control.) |
![]() | HasChildViewState | Gets a value indicating whether the current server control's child controls have any saved view-state settings.(Inherited from Control.) |
![]() | ID | Gets or sets the programmatic identifier assigned to the server control.(Inherited from Control.) |
![]() | IdSeparator | This API supports the product infrastructure and is not intended to be used directly from your code. Gets the character used to separate control identifiers.(Inherited from Control.) |
![]() | IsChildControlStateCleared | Gets a value indicating whether controls contained within this control have control state.(Inherited from Control.) |
![]() | IsTrackingViewState | Gets a value that indicates whether the server control is saving changes to its view state.(Inherited from Control.) |
![]() | IsViewStateEnabled | Gets a value indicating whether view state is enabled for this control.(Inherited from Control.) |
![]() | LoadViewStateByID | |
![]() | NamingContainer | Gets a reference to the server control's naming container, which creates a unique namespace for differentiating between server controls with the same Control.ID property value.(Inherited from Control.) |
![]() | Page | |
![]() | Parent | Gets a reference to the server control's parent control in the page control hierarchy.(Inherited from Control.) |
![]() | RenderingCompatibility | Gets a value that specifies the ASP.NET version that rendered HTML will be compatible with.(Inherited from Control.) |
![]() | Site | Gets information about the container that hosts the current control when rendered on a design surface.(Inherited from Control.) |
![]() | SkinID | Gets or sets the skin to apply to the HierarchicalDataSourceControl control.(Overrides Control.SkinID.) |
![]() | TemplateControl | Gets or sets a reference to the template that contains this control. (Inherited from Control.) |
![]() | TemplateSourceDirectory | Gets the virtual directory of the Page or UserControl that contains the current server control.(Inherited from Control.) |
![]() | UniqueID | Gets the unique, hierarchically qualified identifier for the server control.(Inherited from Control.) |
![]() | ValidateRequestMode | Gets or sets a value that indicates whether the control checks client input from the browser for potentially dangerous values.(Inherited from Control.) |
![]() | ViewState | Gets a dictionary of state information that allows you to save and restore the view state of a server control across multiple requests for the same page.(Inherited from Control.) |
![]() | ViewStateIgnoresCase | |
![]() | ViewStateMode | Gets or sets the view-state mode of this control.(Inherited from Control.) |
![]() | Visible | Gets or sets a value indicating whether the control is visually displayed.(Overrides Control.Visible.) |
Name | Description | |
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![]() | AddedControl(Control, Int32) | |
![]() | AddParsedSubObject(Object) | Notifies the server control that an element, either XML or HTML, was parsed, and adds the element to the server control's ControlCollection object.(Inherited from Control.) |
![]() | ApplyStyleSheetSkin(Page) | Applies the style properties that are defined in the page style sheet to the control.(Overrides Control.ApplyStyleSheetSkin(Page).) |
![]() | BeginRenderTracing(TextWriter, Object) | Begins design-time tracing of rendering data.(Inherited from Control.) |
![]() | BuildProfileTree(String, Boolean) | |
![]() | ClearCachedClientID() | |
![]() | ClearChildControlState() | Deletes the control-state information for the server control's child controls. (Inherited from Control.) |
![]() | ClearChildState() | Deletes the view-state and control-state information for all the server control's child controls.(Inherited from Control.) |
![]() | ClearChildViewState() | Deletes the view-state information for all the server control's child controls.(Inherited from Control.) |
![]() | ClearEffectiveClientIDMode() | This API supports the product infrastructure and is not intended to be used directly from your code. Sets the ClientIDMode property of the current control instance and of any child controls to Inherit.(Inherited from Control.) |
![]() | CreateChildControls() | Called by the ASP.NET page framework to notify server controls that use composition-based implementation to create any child controls they contain in preparation for posting back or rendering.(Inherited from Control.) |
![]() | CreateControlCollection() | Creates a new ControlCollection object to hold the child controls (both literal and server) of the server control.(Overrides Control.CreateControlCollection().) |
![]() | DataBind() | Binds a data source to the invoked server control and all its child controls.(Inherited from Control.) |
![]() | DataBind(Boolean) | Binds a data source to the invoked server control and all its child controls with an option to raise the DataBinding event. (Inherited from Control.) |
![]() | DataBindChildren() | Binds a data source to the server control's child controls.(Inherited from Control.) |
![]() | Dispose() | Enables a server control to perform final clean up before it is released from memory.(Inherited from Control.) |
![]() | EndRenderTracing(TextWriter, Object) | Ends design-time tracing of rendering data.(Inherited from Control.) |
![]() | EnsureChildControls() | Determines whether the server control contains child controls. If it does not, it creates child controls.(Inherited from Control.) |
![]() | EnsureID() | Creates an identifier for controls that do not have an identifier assigned.(Inherited from Control.) |
![]() | Equals(Object) | Determines whether the specified object is equal to the current object.(Inherited from Object.) |
![]() | Finalize() | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.) |
![]() | FindControl(String) | Searches the current naming container for a server control with the specified id parameter.(Overrides Control.FindControl(String).) |
![]() | FindControl(String, Int32) | This API supports the product infrastructure and is not intended to be used directly from your code. Searches the current naming container for a server control with the specified id and an integer, specified in the pathOffset parameter, which aids in the search. You should not override this version of the FindControl method.(Inherited from Control.) |
![]() | Focus() | Sets input focus to the control.(Overrides Control.Focus().) |
![]() | GetDesignModeState() | This API supports the product infrastructure and is not intended to be used directly from your code. Gets design-time data for a control.(Inherited from Control.) |
![]() | GetHashCode() | Serves as the default hash function. (Inherited from Object.) |
![]() | GetHierarchicalView(String) | Gets the view helper object for the IHierarchicalDataSource interface for the specified path. |
![]() | GetRouteUrl(Object) | Gets the URL that corresponds to a set of route parameters.(Inherited from Control.) |
![]() | GetRouteUrl(RouteValueDictionary) | Gets the URL that corresponds to a set of route parameters.(Inherited from Control.) |
![]() | GetRouteUrl(String, Object) | Gets the URL that corresponds to a set of route parameters and a route name.(Inherited from Control.) |
![]() | GetRouteUrl(String, RouteValueDictionary) | Gets the URL that corresponds to a set of route parameters and a route name.(Inherited from Control.) |
![]() | GetType() | |
![]() | GetUniqueIDRelativeTo(Control) | |
![]() | HasControls() | Determines if the server control contains any child controls.(Overrides Control.HasControls().) |
![]() | HasEvents() | Returns a value indicating whether events are registered for the control or any child controls.(Inherited from Control.) |
![]() | IsLiteralContent() | This API supports the product infrastructure and is not intended to be used directly from your code. Determines if the server control holds only literal content.(Inherited from Control.) |
![]() | LoadControlState(Object) | Restores control-state information from a previous page request that was saved by the SaveControlState method.(Inherited from Control.) |
![]() | LoadViewState(Object) | Restores view-state information from a previous page request that was saved by the SaveViewState method.(Inherited from Control.) |
![]() | MapPathSecure(String) | Retrieves the physical path that a virtual path, either absolute or relative, maps to.(Inherited from Control.) |
![]() | MemberwiseClone() | |
![]() | OnBubbleEvent(Object, EventArgs) | Determines whether the event for the server control is passed up the page's UI server control hierarchy.(Inherited from Control.) |
![]() | OnDataBinding(EventArgs) | Raises the DataBinding event.(Inherited from Control.) |
![]() | OnDataSourceChanged(EventArgs) | Raises the DataSourceChanged event. |
![]() | OnInit(EventArgs) | |
![]() | OnLoad(EventArgs) | |
![]() | OnPreRender(EventArgs) | |
![]() | OnUnload(EventArgs) | |
![]() | OpenFile(String) | |
![]() | RaiseBubbleEvent(Object, EventArgs) | Assigns any sources of the event and its information to the control's parent.(Inherited from Control.) |
![]() | RemovedControl(Control) | |
![]() | Render(HtmlTextWriter) | Sends server control content to a provided HtmlTextWriter object, which writes the content to be rendered on the client.(Inherited from Control.) |
![]() | RenderChildren(HtmlTextWriter) | Outputs the content of a server control's children to a provided HtmlTextWriter object, which writes the content to be rendered on the client.(Inherited from Control.) |
![]() | RenderControl(HtmlTextWriter) | Outputs server control content to a provided HtmlTextWriter object and stores tracing information about the control if tracing is enabled.(Overrides Control.RenderControl(HtmlTextWriter).) |
![]() | RenderControl(HtmlTextWriter, ControlAdapter) | Outputs server control content to a provided HtmlTextWriter object using a provided ControlAdapter object.(Inherited from Control.) |
![]() | ResolveAdapter() | Gets the control adapter responsible for rendering the specified control.(Inherited from Control.) |
![]() | ResolveClientUrl(String) | Gets a URL that can be used by the browser.(Inherited from Control.) |
![]() | ResolveUrl(String) | Converts a URL into one that is usable on the requesting client.(Inherited from Control.) |
![]() | SaveControlState() | Saves any server control state changes that have occurred since the time the page was posted back to the server.(Inherited from Control.) |
![]() | SaveViewState() | Saves any server control view-state changes that have occurred since the time the page was posted back to the server.(Inherited from Control.) |
![]() | SetDesignModeState(IDictionary) | Sets design-time data for a control.(Inherited from Control.) |
![]() | SetRenderMethodDelegate(RenderMethod) | This API supports the product infrastructure and is not intended to be used directly from your code. Assigns an event handler delegate to render the server control and its content into its parent control.(Inherited from Control.) |
![]() | SetTraceData(Object, Object) | Sets trace data for design-time tracing of rendering data, using the trace data key and the trace data value.(Inherited from Control.) |
![]() | SetTraceData(Object, Object, Object) | Sets trace data for design-time tracing of rendering data, using the traced object, the trace data key, and the trace data value.(Inherited from Control.) |
![]() | ToString() | Returns a string that represents the current object.(Inherited from Object.) |
![]() | TrackViewState() | Causes tracking of view-state changes to the server control so they can be stored in the server control's StateBag object. This object is accessible through the Control.ViewState property.(Inherited from Control.) |
Name | Description | |
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![]() | DataBinding | Occurs when the server control binds to a data source.(Inherited from Control.) |
![]() | Disposed | Occurs when a server control is released from memory, which is the last stage of the server control lifecycle when an ASP.NET page is requested.(Inherited from Control.) |
![]() | Init | Occurs when the server control is initialized, which is the first step in its lifecycle.(Inherited from Control.) |
![]() | Load | |
![]() | PreRender | |
![]() | Unload | Occurs when the server control is unloaded from memory.(Inherited from Control.) |
Name | Description | |
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![]() ![]() | IHierarchicalDataSource.DataSourceChanged | This API supports the product infrastructure and is not intended to be used directly from your code. Occurs when the HierarchicalDataSourceControl has changed in some way that affects data-bound controls. |
![]() ![]() | IControlDesignerAccessor.GetDesignModeState() | For a description of this member, see IControlDesignerAccessor.GetDesignModeState.(Inherited from Control.) |
![]() ![]() | IControlDesignerAccessor.SetDesignModeState(IDictionary) | For a description of this member, see IControlDesignerAccessor.SetDesignModeState. (Inherited from Control.) |
![]() ![]() | IControlDesignerAccessor.SetOwnerControl(Control) | This API supports the product infrastructure and is not intended to be used directly from your code. For a description of this member, see IControlDesignerAccessor.SetOwnerControl. (Inherited from Control.) |
![]() ![]() | IHierarchicalDataSource.GetHierarchicalView(String) | This API supports the product infrastructure and is not intended to be used directly from your code. Gets the view helper object for the IHierarchicalDataSource interface for the specified path. |
![]() ![]() | IParserAccessor.AddParsedSubObject(Object) | For a description of this member, see IParserAccessor.AddParsedSubObject. (Inherited from Control.) |
![]() ![]() | IControlBuilderAccessor.ControlBuilder | For a description of this member, see IControlBuilderAccessor.ControlBuilder. (Inherited from Control.) |
![]() ![]() | IControlDesignerAccessor.UserData | For a description of this member, see IControlDesignerAccessor.UserData. (Inherited from Control.) |
![]() ![]() | IDataBindingsAccessor.DataBindings | For a description of this member, see IDataBindingsAccessor.DataBindings. (Inherited from Control.) |
![]() ![]() | IDataBindingsAccessor.HasDataBindings | For a description of this member, see IDataBindingsAccessor.HasDataBindings. (Inherited from Control.) |
![]() ![]() | IExpressionsAccessor.Expressions | For a description of this member, see IExpressionsAccessor.Expressions. (Inherited from Control.) |
![]() ![]() | IExpressionsAccessor.HasExpressions | For a description of this member, see IExpressionsAccessor.HasExpressions. (Inherited from Control.) |
Name | Description | |
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![]() | FindDataSourceControl() | Returns the data source that is associated with the data control for the specified control.(Defined by DynamicDataExtensions.) |
![]() | FindFieldTemplate(String) | Returns the field template for the specified column in the specified control's naming container.(Defined by DynamicDataExtensions.) |
![]() | FindMetaTable() | Returns the metatable object for the containing data control.(Defined by DynamicDataExtensions.) |
ASP.NET supports a controls data-binding architecture that enables Web server controls to bind to data and present it in a consistent fashion. Web server controls that bind to data are called data-bound controls, and the classes that facilitate binding are called data source controls. Data source controls can represent any data source: a file, a stream, a relational database, a business object, and so on. Data source controls present data in a consistent way to data-bound controls, regardless of the source or format of the underlying data.
Data source controls that represent hierarchical data derive from the HierarchicalDataSourceControl class, while data source controls that represent lists or tables of data derive from the DataSourceControl class. The HierarchicalDataSourceControl class is the base implementation of the IHierarchicalDataSource interface, which defines a single method to retrieve hierarchical data source view objects associated with the data source control, GetHierarchicalView.
You can think of a data source control as the combination of the HierarchicalDataSourceControl object and its associated views on the underlying data, called data source view objects. While data source controls that represent tabular data are typically associated with only one named view, the HierarchicalDataSourceControl class supports a data source view for each level of hierarchical data that the data source control represents. The level of hierarchical data is identified by a unique hierarchical path, passed to the GetHierarchicalView method in the viewPath parameter. Each HierarchicalDataSourceView object defines the capabilities of a data source control for the hierarchical level represented, and performs operations such as insert, update, delete, and sort.
Web server controls that derive from the HierarchicalDataBoundControl class, such as TreeView, use hierarchical data source controls to bind to hierarchical data.
Data source controls are implemented as controls to enable declarative persistence and to optionally permit participation in state management. Data source controls have no visual rendering, and therefore do not support themes.
The following code example demonstrates how to extend the abstract HierarchicalDataSourceControl class and the HierarchicalDataSourceView class, and implement the IHierarchicalEnumerable and IHierarchyData interfaces to create a hierarchical data source control that retrieves file system information. The FileSystemDataSource control enables Web server controls to bind to FileSystemInfo objects and display basic file system information. The FileSystemDataSource class in the example provides the implementation of the GetHierarchicalView method, which retrieves a FileSystemDataSourceView object. The FileSystemDataSourceView object retrieves the data from the underlying data storage, in this case the file system information on the Web server. For security purposes, file system information is displayed only if the data source control is being used in a localhost, authenticated scenario, and only starts with the virtual directory that the Web Forms page using the data source control resides in. Finally, two classes that implement IHierarchicalEnumerable and IHierarchyData are provided to wrap the FileSystemInfo objects that FileSystemDataSource uses.
Imports System Imports System.Collections Imports System.IO Imports System.Runtime.InteropServices Imports System.Security.Permissions Imports System.Web Imports System.Web.UI Imports System.Web.UI.WebControls Namespace Samples.AspNet Public Class FileSystemDataSource Inherits HierarchicalDataSourceControl Public Sub New() End Sub Private view As FileSystemDataSourceView = Nothing Protected Overrides Function GetHierarchicalView( _ ByVal viewPath As String) As HierarchicalDataSourceView view = New FileSystemDataSourceView(viewPath) Return view End Function End Class Public Class FileSystemDataSourceView Inherits HierarchicalDataSourceView Private _viewPath As String Public Sub New(ByVal viewPath As String) Dim currentRequest As HttpRequest = HttpContext.Current.Request If viewPath = "" Then _viewPath = currentRequest.MapPath(currentRequest.ApplicationPath) Else _viewPath = Path.Combine(currentRequest.MapPath(currentRequest.ApplicationPath), viewPath) End If End Sub 'NewNew ' Starting with the rootNode, recursively build a list of ' FileSystemInfo nodes, create FileSystemHierarchyData ' objects, add them all to the FileSystemHierarchicalEnumerable, ' and return the list. Public Overrides Function [Select]() As IHierarchicalEnumerable Dim currentRequest As HttpRequest = HttpContext.Current.Request ' SECURITY: There are many security issues that can be raised ' SECURITY: by exposing the file system structure of a Web server ' SECURITY: to an anonymous user in a limited trust scenario such as ' SECURITY: a Web page served on an intranet or the Internet. ' SECURITY: For this reason, the FileSystemDataSource only ' SECURITY: shows data when the HttpRequest is received ' SECURITY: from a local Web server. In addition, the data source ' SECURITY: does not display data to anonymous users. If currentRequest.IsAuthenticated AndAlso _ (currentRequest.UserHostAddress = "127.0.0.1" OrElse _ currentRequest.UserHostAddress = "::1") Then Dim rootDirectory As New DirectoryInfo(_viewPath) Dim fshe As New FileSystemHierarchicalEnumerable() Dim fsi As FileSystemInfo For Each fsi In rootDirectory.GetFileSystemInfos() fshe.Add(New FileSystemHierarchyData(fsi)) Next fsi Return fshe Else Throw New NotSupportedException( _ "The FileSystemDataSource only " + _ "presents data in an authenticated, localhost context.") End If End Function 'SelectSelect End Class 'FileSystemDataSourceView Public Class FileSystemHierarchicalEnumerable Inherits ArrayList Implements IHierarchicalEnumerable Public Sub New() End Sub Public Overridable Function GetHierarchyData( _ ByVal enumeratedItem As Object) As IHierarchyData _ Implements IHierarchicalEnumerable.GetHierarchyData Return CType(enumeratedItem, IHierarchyData) End Function End Class Public Class FileSystemHierarchyData Implements IHierarchyData Public Sub New(ByVal obj As FileSystemInfo) fileSystemObject = obj End Sub Private fileSystemObject As FileSystemInfo = Nothing Public Overrides Function ToString() As String Return fileSystemObject.Name End Function ' IHierarchyData implementation. Public Overridable ReadOnly Property HasChildren() As Boolean _ Implements IHierarchyData.HasChildren Get If GetType(DirectoryInfo) Is fileSystemObject.GetType() Then Dim temp As DirectoryInfo = _ CType(fileSystemObject, DirectoryInfo) Return temp.GetFileSystemInfos().Length > 0 Else Return False End If End Get End Property ' DirectoryInfo returns the OriginalPath, while FileInfo returns ' a fully qualified path. Public Overridable ReadOnly Property Path() As String _ Implements IHierarchyData.Path Get Return fileSystemObject.ToString() End Get End Property Public Overridable ReadOnly Property Item() As Object _ Implements IHierarchyData.Item Get Return fileSystemObject End Get End Property Public Overridable ReadOnly Property Type() As String _ Implements IHierarchyData.Type Get Return "FileSystemData" End Get End Property Public Overridable Function GetChildren() _ As IHierarchicalEnumerable _ Implements IHierarchyData.GetChildren Dim children As New FileSystemHierarchicalEnumerable() If GetType(DirectoryInfo) Is fileSystemObject.GetType() Then Dim temp As DirectoryInfo = _ CType(fileSystemObject, DirectoryInfo) Dim fsi As FileSystemInfo For Each fsi In temp.GetFileSystemInfos() children.Add(New FileSystemHierarchyData(fsi)) Next fsi End If Return children End Function 'GetChildren Public Overridable Function GetParent() As IHierarchyData _ Implements IHierarchyData.GetParent Dim parentContainer As New FileSystemHierarchicalEnumerable() If GetType(DirectoryInfo) Is fileSystemObject.GetType() Then Dim temp As DirectoryInfo = _ CType(fileSystemObject, DirectoryInfo) Return New FileSystemHierarchyData(temp.Parent) ElseIf GetType(FileInfo) Is fileSystemObject.GetType() Then Dim temp As FileInfo = CType(fileSystemObject, FileInfo) Return New FileSystemHierarchyData(temp.Directory) End If ' If FileSystemObj is any other kind of FileSystemInfo, ignore it. Return Nothing End Function 'GetParent End Class 'FileSystemHierarchyData End Namespace
The following code example demonstrates how to declaratively bind a TreeView control to file system data using the FileSystemDataSource example.
<%@ Page Language="VB" %> <%@ Register Tagprefix="aspSample" Namespace="Samples.AspNet" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server"> <title>ASP.NET Example</title> </head> <body> <form id="form1" runat="server"> <asp:treeview id="TreeView1" runat="server" datasourceid="FileSystemDataSource1" /> <aspSample:filesystemdatasource id = "FileSystemDataSource1" runat = "server" /> </form> </body> </html>
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.