Method IdentifyGraphicsOverlayAsync

IdentifyGraphicsOverlayAsync(GraphicsOverlay, Point, Double, Boolean)

Identifies the topmost graphic in the specified graphics overlay, at the given screen point.

Declaration

public async Task<IdentifyGraphicsOverlayResult> IdentifyGraphicsOverlayAsync(GraphicsOverlay graphicsOverlay, Point screenPoint, double tolerance, bool returnPopupsOnly)

Parameters

Type	Name	Description
GraphicsOverlay	graphicsOverlay	The graphics overlay in which to identify the graphic.
System.Windows.Point	screenPoint	The screen coordinates to identify the graphic.
System.Double	tolerance	A radius in device-independent pixels (DIP) that specifies how precise the identify operation should be.
System.Boolean	returnPopupsOnly	`true` includes only popups in the identify results. An error is returned if the layer does not have popups. `false` includes both geoelements and popups in the identify results.

Returns

Type	Description
System.Threading.Tasks.Task<IdentifyGraphicsOverlayResult>	A task that represents the asynchronous identify operation on the specified graphics overlay. The value of the TResult parameter contains a read-only collection of Graphic

Remarks

As locations from user gestures are not always accurate to the exact pixel, you can define a tolerance for the identify operation. The tolerance parameter sets the radius of a circle, centered at the specified coordinates, in device-independent pixels (DIP). If the tolerance value is 0, identify performs the test at the specified coordinates. If it is greater than 0, identify tests inside the circle. For touch displays a value of 22 is recommended to cover an average finger tap. The maximum allowed value is 100 DIPs.

The returnPopupsOnly parameter controls which properties are populated in the IdentifyGraphicsOverlayResult instance. If returnPopupsOnly is true, Popups is populated. If the overlay does not have popups an error is returned. If returnPopupsOnly is false, Graphics and Popups are populated, if the overlay has popups.

Exceptions

Type	Condition
System.ArgumentNullException	graphicsOverlay

Applies to

Platforms and versions

Target	Versions
.NET Windows	100.13 - 200.5
.NET Framework	100.0 - 200.5

IdentifyGraphicsOverlayAsync(GraphicsOverlay, Point, Double, Boolean, Int64)

Identifies a limited number of graphics in the specified graphics overlay, at the given screen point.