Question

在第3章GazeGestureManager.cs中：

using UnityEngine;
using UnityEngine.VR.WSA.Input;

public class GazeGestureManager : MonoBehaviour
{
    public static GazeGestureManager Instance { get; private set; }

    // Represents the hologram that is currently being gazed at.
    public GameObject FocusedObject { get; private set; }

    GestureRecognizer recognizer;

    // Use this for initialization
    void Start()
    {
        Instance = this;

        // Set up a GestureRecognizer to detect Select gestures.
        recognizer = new GestureRecognizer();
        recognizer.TappedEvent += (source, tapCount, ray) =>
        {
            // Send an OnSelect message to the focused object and its ancestors.
            if (FocusedObject != null)
            {
                FocusedObject.SendMessageUpwards("OnSelect");
            }
        };
        recognizer.StartCapturingGestures();
    }

    // Update is called once per frame
    void Update()
    {
        // Figure out which hologram is focused this frame.
        GameObject oldFocusObject = FocusedObject;

        // Do a raycast into the world based on the user's
        // head position and orientation.
        var headPosition = Camera.main.transform.position;
        var gazeDirection = Camera.main.transform.forward;

        RaycastHit hitInfo;
        if (Physics.Raycast(headPosition, gazeDirection, out hitInfo))
        {
            // If the raycast hit a hologram, use that as the focused object.
            FocusedObject = hitInfo.collider.gameObject;
        }
        else
        {
            // If the raycast did not hit a hologram, clear the focused object.
            FocusedObject = null;
        }

        // If the focused object changed this frame,
        // start detecting fresh gestures again.
        if (FocusedObject != oldFocusObject)
        {
            recognizer.CancelGestures();
            recognizer.StartCapturingGestures();
        }
    }
}

我真的不明白这一行：

recognizer.TappedEvent += (source, tapCount, ray) =>

()内部是什么，为什么有一个=>运算符以及它的用途是什么？

Answer 1

看看C＃Lambda运算符here。它将块与左侧的输入变量分开。所以看起来块将在tapped事件上执行，并且参数（source，tapCount，ray）将被传递并且可以在块中使用。

Answer 2

我喜欢将其视为“处理事件或回调的内联委托”。希望有所帮助：）

hololens 101第3章：什么是“=＆gt;”对于？

2 个答案: