Method IdentifyGraphicsOverlaysAsync
IdentifyGraphicsOverlaysAsync(Point, Double, Boolean)
Identifies the topmost graphic in each graphics overlay, at the given screen point.
Declaration
public async Task<IReadOnlyList<IdentifyGraphicsOverlayResult>> IdentifyGraphicsOverlaysAsync(Point screenPoint, double tolerance, bool returnPopupsOnly)Parameters
| Type | Name | Description |
|---|---|---|
| System.Windows.Point | screenPoint | The screen coordinates to identify the graphics. |
| System.Double | tolerance | A radius in device-independent pixels (DIP) that specifies how precise the identify operation should be. |
| System.Boolean | returnPopupsOnly |
|
Returns
| Type | Description |
|---|---|
| System.Threading.Tasks.Task<System.Collections.Generic.IReadOnlyList<IdentifyGraphicsOverlayResult>> | A task that represents the asynchronous identify operation on all graphics overlays in the view The value of the TResult parameter contains a read-only collection of IdentifyGraphicsOverlayResult in top to bottom order. |
Remarks
Results are returned in the same order as the graphic overlays in the GraphicsOverlays collection.
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 true, only Popups is populated. If false, both Graphics and
Popups are populated, if the overlay has popups.
Applies to
Platforms and versions
| Target | Versions |
|---|---|
| .NET Windows | 100.13 - 200.6 |
| .NET Framework | 100.0 - 200.6 |
IdentifyGraphicsOverlaysAsync(Point, Double, Boolean, Int64)
Identifies a limited number of graphics in all graphics overlays, at the given screen point.
Declaration
public async Task<IReadOnlyList<IdentifyGraphicsOverlayResult>> IdentifyGraphicsOverlaysAsync(Point screenPoint, double tolerance, bool returnPopupsOnly, long maximumResultsPerOverlay)Parameters
| Type | Name | Description |
|---|---|---|
| System.Windows.Point | screenPoint | The screen coordinates to identify the graphics. |
| System.Double | tolerance | A radius in device-independent pixels (DIP) that specifies how precise the identify operation should be. |
| System.Boolean | returnPopupsOnly |
|
| System.Int64 | maximumResultsPerOverlay | The maximum number of graphics and/or popups returned in the IdentifyGraphicsOverlayResult per graphics overlay. A value of -1 indicates unlimited results. |
Returns
| Type | Description |
|---|---|
| System.Threading.Tasks.Task<System.Collections.Generic.IReadOnlyList<IdentifyGraphicsOverlayResult>> | A task that represents the asynchronous identify operation on all graphics overlays in the view The value of the TResult parameter contains a read-only collection of IdentifyGraphicsOverlayResult in top to bottom order. |
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 true, only Popups is populated. If false, both Graphics and
Popups are populated, if the overlay has popups.
Results are returned in a top-to-bottom order.
Applies to
Platforms and versions
| Target | Versions |
|---|---|
| .NET Windows | 100.13 - 200.6 |
| .NET Framework | 100.0 - 200.6 |