ImageMap Class

This is a derived WebControl class that can be used to render an image map (an image with hyperlink hot spots).

Definition

Namespace: EWSoftware.ImageMaps.Web.Controls
Assembly: EWSoftware.ImageMaps.Web.Controls (in EWSoftware.ImageMaps.Web.Controls.dll) Version: 2023.1.3.0
public class ImageMap : WebControl, IPostBackEventHandler, 
	IImageMap
Inheritance
Object    Control    WebControl    ImageMap
Implements
IImageMap, IPostBackEventHandler

Example

This example demonstrates creating web server ImageMap controls and the various shapes derived from ImageAreaBase.

The control definitions are in the HTML. This shows an example of each image area type and the various actions that can be performed.

Example Control Usage
<%@ Register TagPrefix="ewsi" Namespace="EWSoftware.ImageMaps.Web.Controls"
  Assembly="EWSoftware.ImageMaps.Web.Controls" %>

<ewsi:ImageMap id="imMap" runat="server" ToolTip="A test image"
  ImageUrl="Images/Shapes.jpg" BorderStyle="Solid" BorderWidth="1px">
  <ewsi:ImageAreaPolygon
    ToolTip="Load google.com in search pane"
    NavigateUrl="http://www.google.com" Target="Search"
    Coordinates="150,156,218,256,250,222,244,200,268,188,294,188,258,140,220,144,178,124"
    TabIndex="4" AccessKey="P"></ewsi:ImageAreaPolygon>
  <ewsi:ImageAreaRectangle ToolTip="Go to www.EWoodruff.us"
    Rectangle="15, 16, 149, 93" NavigateUrl="http://www.ewoodruff.us"
    TabIndex="2" AccessKey="R"></ewsi:ImageAreaRectangle>
  <ewsi:ImageAreaRectangle ToolTip="Only displays this tool tip"
    Rectangle="316, 175, 208, 122" Action="None">
    </ewsi:ImageAreaRectangle>
  <ewsi:ImageAreaCircle
    ToolTip="Load Microsoft.com in a new window" CenterPoint="380, 88"
    Radius="60" NavigateUrl="http://www.microsoft.com" Target="Blank"
    TabIndex="3" AccessKey="C"></ewsi:ImageAreaCircle>
  <ewsi:ImageAreaRectangle ToolTip="Execute client-side script"
    Rectangle="12, 202, 134, 46"
    NavigateUrl="javascript: alert('Execute any client-side script');"
    TabIndex="5"></ewsi:ImageAreaRectangle>
  <ewsi:ImageAreaRectangle
    ToolTip="Click to enable/disable the other image map"
    Rectangle="6, 262, 194, 40" TabIndex="6" Action="PostBack"
    AccessKey="D"></ewsi:ImageAreaRectangle>
</ewsi:ImageMap>

<ewsi:ImageMap id="imClickMap" runat="server" ToolTip="Click an area to post back"
  ImageUrl="Images/PostBack.jpg" CausesValidation="True">
  <ewsi:ImageAreaRectangle Rectangle="0,0,20,20" Action="PostBack"
    ToolTip="Area 1" TabIndex="7" AccessKey="1" />
  <ewsi:ImageAreaRectangle Rectangle="80,0,20,20" Action="PostBack"
    ToolTip="Area 2" TabIndex="8" AccessKey="2" />
  <ewsi:ImageAreaRectangle Rectangle="0,80,20,20" Action="PostBack"
    ToolTip="Area 3" TabIndex="9" AccessKey="3" />
  <ewsi:ImageAreaRectangle Rectangle="80,80,20,20" Action="PostBack"
    ToolTip="Area 4" TabIndex="10" AccessKey="4" />
</ewsi:ImageMap>

The code in the code-behind file for the event handlers fired by the image areas that have their Action set to PostBack:

C#
/// <summary>
/// This event is fired by the image area at the bottom of the left-side
/// image map.
/// </summary>
/// <param name="sender">The sender of the event</param>
/// <param name="e">The event arguments</param>
/// <remarks>The parameters are not used and it does not cause validation
/// events to fire.  It is used to enable or disable the right-side image
/// map.</remarks>
protected void imMap_Click(object sender, ImageMapClickEventArgs e)
{
    imClickMap.Enabled = !imClickMap.Enabled;
    lblClickMsg.Text = String.Empty;
    lblEnabledMsg.Text = String.Format(CultureInfo.CurrentCulture, "Image map {0}",
        imClickMap.Enabled ? "enabled" : "disabled");

    // Apply a filter to "gray out" the image map and change the tool tip
    if(!imClickMap.Enabled)
    {
        imClickMap.Style.Add("opacity", ".25");
        imClickMap.Style.Add("filter", "Alpha(Opacity=25)");  // For older browsers
        imClickMap.ToolTip = "Disabled";
    }
    else
    {
        imClickMap.Style.Remove("opacity");
        imClickMap.Style.Remove("filter");
        imClickMap.ToolTip = "Click an area to post back";
    }
}

/// <summary>
/// This event is fired when an area on the right-side image map is clicked
/// </summary>
/// <param name="sender">The sender of the event</param>
/// <param name="e">The event arguments</param>
/// <remarks>It receives the zero based index of the clicked area plus the
/// X,Y coordinates of the clicked point within the area.  This image map
/// also causes validation events to fire.</remarks>
protected void imClickMap_Click(object sender, ImageMapClickEventArgs e)
{
    int clickCount = 0;

    if(Page.IsValid)
    {
        lblClickMsg.Text = String.Format(CultureInfo.CurrentCulture, "Clicked Area #{0}", e.AreaIndex + 1);

        // X and Y are only sent back by browsers that support the
        // event.offsetX and event.offsetY properties.
        if(e.XCoordinate != -1)
            lblClickMsg.Text += String.Format(CultureInfo.CurrentCulture, "<br>At X,Y {0},{1}",
                e.XCoordinate, e.YCoordinate);

        // Track the click count in the Tag property to test view state
        if(imClickMap.Areas[e.AreaIndex].Tag != null)
            clickCount = (int)imClickMap.Areas[e.AreaIndex].Tag;

        clickCount++;

        lblClickMsg.Text += String.Format(CultureInfo.CurrentCulture, "<br>It has been clicked {0} times",
            clickCount);

        imClickMap.Areas[e.AreaIndex].Tag = clickCount;
    }
}

Constructors

ImageMapInitializes a new instance of the ImageMap class

Properties

AccessKeyGets or sets the access key that allows you to quickly navigate to the Web server control.
(Inherited from WebControl)
AdapterGets the browser-specific adapter for the control.
(Inherited from Control)
AppRelativeTemplateSourceDirectoryGets or sets the application-relative virtual directory of the Page or UserControl object that contains this control.
(Inherited from Control)
Areas This returns the collection of areas defined for the image map
AttributesGets the collection of arbitrary attributes (for rendering only) that do not correspond to properties on the control.
(Inherited from WebControl)
BindingContainerGets the control that contains this control's data binding.
(Inherited from Control)
BorderColorGets or sets the border color of the Web control.
(Inherited from WebControl)
BorderStyleGets or sets the border style of the Web server control.
(Inherited from WebControl)
BorderWidthGets or sets the border width of the Web server control.
(Inherited from WebControl)
CausesValidation This property is used to determine whether or not validation occurs when an image map area is clicked
ChildControlsCreatedGets a value that indicates whether the server control's child controls have been created.
(Inherited from Control)
ClientIDGets the control ID for HTML markup that is generated by ASP.NET.
(Inherited from Control)
ClientIDModeGets or sets the algorithm that is used to generate the value of the ClientID property.
(Inherited from Control)
ClientIDSeparatorGets a character value representing the separator character used in the ClientID property.
(Inherited from Control)
ContextGets the HttpContext object associated with the server control for the current Web request.
(Inherited from Control)
ControlsGets a ControlCollection object that represents the child controls for a specified server control in the UI hierarchy.
(Inherited from Control)
ControlStyleGets the style of the Web server control. This property is used primarily by control developers.
(Inherited from WebControl)
ControlStyleCreatedGets a value indicating whether a Style object has been created for the ControlStyle property. This property is primarily used by control developers.
(Inherited from WebControl)
CssClassGets or sets the Cascading Style Sheet (CSS) class rendered by the Web server control on the client.
(Inherited from WebControl)
DataItemContainerGets a reference to the naming container if the naming container implements IDataItemContainer.
(Inherited from Control)
DataKeysContainerGets a reference to the naming container if the naming container implements IDataKeysControl.
(Inherited from Control)
DesignModeGets a value indicating whether a control is being used on a design surface.
(Inherited from Control)
EnabledGets or sets a value indicating whether the Web server control is enabled.
(Inherited from WebControl)
EnableThemingGets or sets a value indicating whether themes apply to this control.
(Inherited from WebControl)
EnableViewStateGets 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)
EventsGets a list of event handler delegates for the control. This property is read-only.
(Inherited from Control)
ForceScriptRegistration This property is used to force registration of the postback script even if it may not be used
FormId This property can be used to specify the form control ID for the page to override the default behavior of OnPreRender(EventArgs).
HasAttributesGets a value indicating whether the control has attributes set.
(Inherited from WebControl)
HasChildViewStateGets a value indicating whether the current server control's child controls have any saved view-state settings.
(Inherited from Control)
IDGets or sets the programmatic identifier assigned to the server control.
(Inherited from Control)
IdSeparatorGets the character used to separate control identifiers.
(Inherited from Control)
ImageAlign Gets or sets the alignment of the image map control in relation to other elements on the web page
ImageMapHeight Gets or sets the height of the image in the image map control in pixels
ImageMapWidth Gets or sets the width of the image in the image map control in pixels
ImageUrl Gets or sets the location of an image to display in the image map control
IsChildControlStateClearedGets a value indicating whether controls contained within this control have control state.
(Inherited from Control)
IsEnabledGets a value indicating whether the control is enabled.
(Inherited from WebControl)
IsTrackingViewStateGets a value that indicates whether the server control is saving changes to its view state.
(Inherited from Control)
IsViewStateEnabledGets a value indicating whether view state is enabled for this control.
(Inherited from Control)
LoadViewStateByIDGets a value indicating whether the control participates in loading its view state by ID instead of index.
(Inherited from Control)
NamingContainerGets a reference to the server control's naming container, which creates a unique namespace for differentiating between server controls with the same ID property value.
(Inherited from Control)
PageGets a reference to the Page instance that contains the server control.
(Inherited from Control)
ParentGets a reference to the server control's parent control in the page control hierarchy.
(Inherited from Control)
RenderingCompatibilityGets a value that specifies the ASP.NET version that rendered HTML will be compatible with.
(Inherited from Control)
SiteGets information about the container that hosts the current control when rendered on a design surface.
(Inherited from Control)
SkinIDGets or sets the skin to apply to the control.
(Inherited from WebControl)
StyleGets a collection of text attributes that will be rendered as a style attribute on the outer tag of the Web server control.
(Inherited from WebControl)
SupportsDisabledAttributeGets a value that indicates whether the control should set the disabled attribute of the rendered HTML element to "disabled" when the control's IsEnabled property is .
(Inherited from WebControl)
TabIndexGets or sets the tab index of the Web server control.
(Inherited from WebControl)
TagKeyGets the HtmlTextWriterTag value that corresponds to this Web server control. This property is used primarily by control developers.
(Inherited from WebControl)
TagNameGets the name of the control tag. This property is used primarily by control developers.
(Inherited from WebControl)
TemplateControlGets or sets a reference to the template that contains this control.
(Inherited from Control)
TemplateSourceDirectoryGets the virtual directory of the Page or UserControl that contains the current server control.
(Inherited from Control)
ToolTip Gets or sets the tool tip text (alternate text) displayed in the image map control when the image is unavailable. Browsers that support the tool tips feature display this text as a tool tip for all undefined areas of the image.
(Overrides WebControlToolTip)
UniqueIDGets the unique, hierarchically qualified identifier for the server control.
(Inherited from Control)
ViewStateGets 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)
ViewStateIgnoresCaseGets a value that indicates whether the StateBag object is case-insensitive.
(Inherited from Control)
ViewStateModeGets or sets the view-state mode of this control.
(Inherited from Control)
VisibleGets or sets a value that indicates whether a server control is rendered as UI on the page.
(Inherited from Control)

Methods

AddAttributesToRender This is overridden to add attributes to the image tag
(Overrides WebControlAddAttributesToRender(HtmlTextWriter))
AddedControlCalled after a child control is added to the Controls collection of the Control object.
(Inherited from Control)
AddParsedSubObjectNotifies 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)
ApplyStyleCopies any nonblank elements of the specified style to the Web control, overwriting any existing style elements of the control. This method is primarily used by control developers.
(Inherited from WebControl)
ApplyStyleSheetSkinApplies the style properties defined in the page style sheet to the control.
(Inherited from Control)
BuildProfileTreeGathers information about the server control and delivers it to the Trace property to be displayed when tracing is enabled for the page.
(Inherited from Control)
ClearCachedClientIDSets the cached ClientID value to .
(Inherited from Control)
ClearChildControlStateDeletes the control-state information for the server control's child controls.
(Inherited from Control)
ClearChildStateDeletes the view-state and control-state information for all the server control's child controls.
(Inherited from Control)
ClearChildViewStateDeletes the view-state information for all the server control's child controls.
(Inherited from Control)
ClearEffectiveClientIDModeSets the ClientIDMode property of the current control instance and of any child controls to Inherit.
(Inherited from Control)
CopyBaseAttributesCopies the properties not encapsulated by the Style object from the specified Web server control to the Web server control that this method is called from. This method is used primarily by control developers.
(Inherited from WebControl)
CreateChildControlsCalled 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)
CreateControlCollectionCreates a new ControlCollection object to hold the child controls (both literal and server) of the server control.
(Inherited from Control)
CreateControlStyleCreates the style object that is used internally by the WebControl class to implement all style related properties. This method is used primarily by control developers.
(Inherited from WebControl)
DataBindBinds 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)
DataBindChildrenBinds a data source to the server control's child controls.
(Inherited from Control)
DisposeEnables a server control to perform final clean up before it is released from memory.
(Inherited from Control)
EnsureChildControlsDetermines whether the server control contains child controls. If it does not, it creates child controls.
(Inherited from Control)
EnsureIDCreates an identifier for controls that do not have an identifier assigned.
(Inherited from Control)
EqualsDetermines whether the specified object is equal to the current object.
(Inherited from Object)
FinalizeAllows 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.
(Inherited from Control)
FindControl(String, Int32)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 {0} Overload method.
(Inherited from Control)
FocusSets input focus to a control.
(Inherited from Control)
GetDesignModeStateGets design-time data for a control.
(Inherited from Control)
GetHashCodeServes as the default hash function.
(Inherited from Object)
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)
GetTypeGets the Type of the current instance.
(Inherited from Object)
GetUniqueIDRelativeToReturns the prefixed portion of the UniqueID property of the specified control.
(Inherited from Control)
HasControlsDetermines if the server control contains any child controls.
(Inherited from Control)
HasEventsReturns a value indicating whether events are registered for the control or any child controls.
(Inherited from Control)
IsLiteralContentDetermines if the server control holds only literal content.
(Inherited from Control)
LoadControlStateRestores control-state information from a previous page request that was saved by the SaveControlState method.
(Inherited from Control)
LoadViewState This is overridden to load view state for the control
(Overrides WebControlLoadViewState(Object))
MapPathSecureRetrieves the physical path that a virtual path, either absolute or relative, maps to.
(Inherited from Control)
MemberwiseCloneCreates a shallow copy of the current Object.
(Inherited from Object)
MergeStyleCopies any nonblank elements of the specified style to the Web control, but will not overwrite any existing style elements of the control. This method is used primarily by control developers.
(Inherited from WebControl)
OnBubbleEventDetermines whether the event for the server control is passed up the page's UI server control hierarchy.
(Inherited from Control)
OnClick This raises the image map Click event
OnDataBindingRaises the DataBinding event.
(Inherited from Control)
OnInitRaises the Init event.
(Inherited from Control)
OnLoadRaises the Load event.
(Inherited from Control)
OnPreRender This is overridden to register the hidden fields used by the postback code if any of the image map areas have their Action set to PostBack. It also registers a script block containing a helper function used in that situation as well.
(Overrides ControlOnPreRender(EventArgs))
OnUnloadRaises the Unload event.
(Inherited from Control)
OpenFileGets a Stream used to read a file.
(Inherited from Control)
RaiseBubbleEventAssigns any sources of the event and its information to the control's parent.
(Inherited from Control)
RaisePostBackEvent This fires the image map Click event if necessary
RemovedControlCalled after a child control is removed from the Controls collection of the Control object.
(Inherited from Control)
Render This is overridden to render the image map HTML
(Overrides WebControlRender(HtmlTextWriter))
RenderBeginTagRenders the HTML opening tag of the control to the specified writer. This method is used primarily by control developers.
(Inherited from WebControl)
RenderChildrenOutputs 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)
RenderContentsRenders the contents of the control to the specified writer. This method is used primarily by control developers.
(Inherited from WebControl)
RenderControl(HtmlTextWriter)Outputs server control content to a provided HtmlTextWriter object and stores tracing information about the control if tracing is enabled.
(Inherited from Control)
RenderControl(HtmlTextWriter, ControlAdapter)Outputs server control content to a provided HtmlTextWriter object using a provided ControlAdapter object.
(Inherited from Control)
RenderEndTagRenders the HTML closing tag of the control into the specified writer. This method is used primarily by control developers.
(Inherited from WebControl)
ResolveAdapterGets the control adapter responsible for rendering the specified control.
(Inherited from Control)
ResolveClientUrlGets a URL that can be used by the browser.
(Inherited from Control)
ResolveUrlConverts a URL into one that is usable on the requesting client.
(Inherited from Control)
SaveControlStateSaves any server control state changes that have occurred since the time the page was posted back to the server.
(Inherited from Control)
SaveViewState This is overridden to save view state for the control
(Overrides WebControlSaveViewState)
SetDesignModeStateSets design-time data for a control.
(Inherited from Control)
SetRenderMethodDelegateAssigns an event handler delegate to render the server control and its content into its parent control.
(Inherited from Control)
ToStringReturns a string that represents the current object.
(Inherited from Object)
TrackViewState This is overridden to track view state for the control
(Overrides WebControlTrackViewState)

Events

Click This event is raised when a hot spot on the image map is clicked
DataBindingOccurs when the server control binds to a data source.
(Inherited from Control)
DisposedOccurs 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)
InitOccurs when the server control is initialized, which is the first step in its lifecycle.
(Inherited from Control)
LoadOccurs when the server control is loaded into the Page object.
(Inherited from Control)
PreRenderOccurs after the Control object is loaded but prior to rendering.
(Inherited from Control)
UnloadOccurs when the server control is unloaded from memory.
(Inherited from Control)

See Also