IImageDisplay2 Interface

Provides access to the Image Display Interface.

Product Availability

Description

This interface is new at ArcGIS 9.3. It supersedes IImageDisplay.

When To Use

Use IImageDisplay to set the size and resolution for MapServer output. MapServer output can be created using ExportMapImage on IMapServer2 and the following methods on IMapServerLayout: ExportLayout, ExportLegend, ExportNorthArrow and ExportScaleBar.

Furthermore, the follwing methods on MapServer depend on ImageDisplay: ComputeScale, Find, Identify, QueryHyperlinks, ToMapPoints and FromMapPoints. For example, both the Find and Identify methods can be performed for only the visible layers in the map. Layer visibility may be dependent on map scale which, in turn, is dependent on the image display. The methods ToPagePoints and FromPagePoints on MapServerLayout also depend on ImageDisplay.

Members

	Name	Description
	DeviceResolution	The device resolution of the image (dots per inch).
	Height	The height of the image in pixels.
	TransparentColor	Transparent color for image types that support transparent color.
	Width	The width of the image in pixels.

Classes that implement IImageDisplay2

Remarks

Setting 0 for either the height or the width for ExportMapImage output results in an error. An ExportMapImage result needs both height and width to be set. In order to control the size of an exported map image, IMapServerInit2 contains two properties: MaxImageHeight and MaxImageWidth. The default value for these properties is 2048 pixels. See ExportMapImage for more information.

ExportLayout does not require that a size be set for the output. Default values are set by the size of the map document itself. Setting 0 height, width, or both for ExportLayout output results in the default sizes as specified in the original ArcMap document layout being used. A new size will only be set when values other than 0 are set for both height and width. See ExportLayout for more information.

ExportLegend output does not require a size. Not setting height and width will result in a default size based on the number of layers, marker size and length of label or description text. When layers become visible and are added to the legend this size is likely to change. This can cause problems with interactive maps.  To best manage the size of the ExportLegend set either the height or width to the required size and set the other value to 0.

ExportNorthArrow output does not require a size. A default size is calculated based on the size of the NorthArrowMarker symbol. Setting 0 for both the height and the width for ExportNorthArrow output results in a default size that best fits the NorthArrowMarker symbol.

ExportScaleBar output requires a size in pixels. Setting 0 for either the height or the width results in an error.