VNImageRequestHandler.Perform(VNRequest[], NSError) Method

Reference

Definition

Namespace:: Vision

Assembly:: Xamarin.iOS.dll

Assembly:: Xamarin.Mac.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Asynchronously executes vision recognition for the specified requests.

[Foundation.Export("performRequests:error:")]
public virtual bool Perform (Vision.VNRequest[] requests, out Foundation.NSError error);

abstract member Perform : Vision.VNRequest[] *  -> bool
override this.Perform : Vision.VNRequest[] *  -> bool

Parameters

requests: VNRequest[]

The array of VNRequest objects to look for.

error: NSError

Returns

Boolean

Attributes: ExportAttribute

Remarks

Image processing can take several seconds and developers should use a background thread to call this method.

System.Threading.Tasks.Task.Run(() =>
{
	using (var requestHandler = new VNImageRequestHandler(img, new NSDictionary()))
	{
		var findFacesRequest = new VNDetectFaceRectanglesRequest(faceDetectionHandler);
		requestHandler.Perform(new[] { findFacesRequest }, out var error);
		if (error != null)
		{
			HandleError(error);
		}
	}
});

Applies to