Unity3D - 無法使用EventSystem在Android中獲取當前選定的遊戲對象

Question

我正在研究Android應用程序Unity3D其中我試圖在unity3d中運行時實例化和銷燬GameObjects。我是統一新人，目前正在研究Google的項目探戈，我只是試圖將一個對象放置在飛機上，然後通過觸摸對該對象執行旋轉或移動操作。

我爲我的3D對象使用FBX文件並利用事件系統來獲取觸摸更新。查找飛機並將物體放置在飛機上，因爲他們在其docs上有明確的教程。但是現在我想通過觸摸來獲得所選的GameObject。

我已經爲導入的fbx對象創建了預製，併爲其添加了一個框對撞機。然後，我添加了一個Physics Raycater到我的Tango相機，並創建了一個EventSystem GameObject以在運行時獲取觸摸事件。見附圖。

我的劇本是這樣的（見IsPointerOverGameObject方法）： -

using UnityEngine; 
using System.Collections; 
using UnityEngine.EventSystems; 
public class KittyUIController : MonoBehaviour 
{ 
public GameObject m_object; 
private TangoPointCloud m_pointCloud; 
private bool isGameObjectSelected = false; 
void Start() 
{ 
    m_pointCloud = FindObjectOfType<TangoPointCloud>(); 
    InventoryItemDisplay.onClick += InventoryItemDisplay_onClick; 
} 
void OnDestroy() 
{ 
    Debug.Log ("MY LOGS - Unsigned-up for onClick"); 
    InventoryItemDisplay.onClick -= InventoryItemDisplay_onClick; 
} 
void Update() 
{ 
    if (Input.touchCount == 1) 
    { 
     Touch t = Input.GetTouch(0); 
     // Trigger place kitten function when single touch ended. 
     if (t.phase == TouchPhase.Ended) { 
      if (m_object != null && !isGameObjectSelected) { 
       Debug.Log ("MY LOGS - Placing object to the plane"); 
       PlaceObject (t.position); 
      } else { 
       isGameObjectSelected = false; 
      } 
     } else if (t.phase == TouchPhase.Began) { 
      IsPointerOverGameObject (t.fingerId); // Here i'm checking weather a GameObject is Touched or not 
     } 
    } 
} 
/* 
* This method will check whether a game object is touched or not using Event System  
*/ 
void IsPointerOverGameObject(int fingerId){ 

    if (EventSystem.current.IsPointerOverGameObject (fingerId)) { 
     isGameObjectSelected = true; 
     Debug.Log ("MY LOGS - Is pointing over game object"); 
     //-------HERE IS THE REAL ISSUE-------// 
     Debug.Log ("MY LOGS - GETTING SELECTED GAMEOBJECT : " + EventSystem.current.currentSelectedGameObject); 
     GameObject go = EventSystem.current.currentSelectedGameObject; 
     Debug.Log ("MY LOGS - Got the game object!!\nTag for game object is : "+go.tag); 
     // Destroy if Object is of type 3D object 
     if (go.tag == "3DObject") { 
      Debug.Log ("MY LOGS - yoo a 3d object is selected"); 
      Destroy (go); 
     } else { 
      Debug.Log ("MY LOGS - Oops the selected object don't have a tag of 3d object"); 
     } 
    } else { 
     Debug.Log ("MY LOGS - Is not pointing over game object"); 
    } 
} 
//-------Click listener to listen to the clicks in Side Panel 
void InventoryItemDisplay_onClick (InventoryItem item, GameObject itemObject) 
{ 
    Debug.Log ("MY LOGS - Vola..You have selected " + item.displayName); 
    m_object = itemObject; 
} 
/* 
* This method will place selected gameobject to the plane  
*/ 
void PlaceObject(Vector2 touchPosition) 
{ 
    // Find the plane. 
    Camera cam = Camera.main; 
    Vector3 planeCenter; 
    Plane plane; 
    if (!m_pointCloud.FindPlane(cam, touchPosition, out planeCenter, out plane)) 
    { 
     Debug.Log("MY LOGS - cannot find plane."); 
     return; 
    } 
    // Place object on the surface, and make it always face the camera. 
    if (Vector3.Angle(plane.normal, Vector3.up) < 30.0f) 
    { 
     Vector3 up = plane.normal; 
     Vector3 right = Vector3.Cross(plane.normal, cam.transform.forward).normalized; 
     Vector3 forward = Vector3.Cross(right, plane.normal).normalized; 
     Instantiate(m_object, planeCenter, Quaternion.LookRotation(forward, up)); 
    } 
    else 
    { 
     Debug.Log("MY LOGS - surface is too steep for kitten to stand on."); 
    } 
    } 
} 

我有一個列表項側面板預製這也越來越在運行時創建。因此，當我觸摸側面板上的列表項來選擇一個對象時，所有內容都在IsPointerOverGameObject方法運行良好，除了打印選定對象的標記。但是，當我碰到放置在屏幕的表面上我的對象，然後它不工作後Debug.Log ("MY LOGS - Is pointing over game object");在IsPointerOverGameObject方法

它會看到我的logcat後得到明確。

logcat的

06-10 15:33:31.094: I/Unity(15009): MY LOGS - Is not pointing over game object 
06-10 15:33:38.619: I/Unity(15009): MY LOGS - Is pointing over game object 
06-10 15:33:38.621: I/Unity(15009): MY LOGS - GETTING SELECTED GAMEOBJECT : InventoryItemDisplay(Clone) (UnityEngine.GameObject) 
06-10 15:33:38.621: I/Unity(15009): MY LOGS - Got the game object!! 
06-10 15:33:38.622: I/Unity(15009): MY LOGS - Oops the selected object don't have a tag of 3d object 
06-10 15:33:38.665: I/Unity(15009): MY LOGS - Vola..You have selected Rose 
06-10 15:33:45.175: I/Unity(15009): MY LOGS - Is not pointing over game object 
06-10 15:33:45.286: I/Unity(15009): MY LOGS - Placing object to the plane 
06-10 15:33:50.379: I/Unity(15009): MY LOGS - Is pointing over game object 
06-10 15:33:50.379: I/Unity(15009): MY LOGS - GETTING SELECTED GAMEOBJECT : 
06-10 15:33:54.558: I/Unity(15009): MY LOGS - Is not pointing over game object 
06-10 15:33:54.686: I/Unity(15009): MY LOGS - Placing object to the plane 
06-10 15:33:54.688: I/Unity(15009): MY LOGS - surface is too steep for kitten to stand on. 

現在，如果你看到第三行logcat的，你會看到，它打印所選的對象：InventoryItemDisplay（克隆），但如果你的下一行在代碼中檢查Debug.Log()，然後你會看到我不打印日誌後\n....這是當我點擊側面板上的項目。現在看到第四個線從logcat的底部。這是當我點擊初始化的遊戲對象時。它甚至不會在該行之後打印任何內容。它直接打印出寫在Touch.Ended條件下的代碼。

ADDING截圖供現場

Answer 1

據我所知， EventSystem.current.currentSelectedGameObject只能參照一個UI對象，即使它沒有明確規定in the documentation。你正在實例化的不是一個UI對象，而只是場景中的一個常規GameObject。我看不到完整的Inspector視圖，但是我可以看到，在實例化過程中，您沒有將Canvas的變換設置爲GameObject的父元素，這就足夠了。

如果您想要在場景中引用GameObject，則需要在實例化過程中存儲對它的引用，或者您需要根據觸摸的位置進行Raycast來獲取它。該方法取決於你想要達到的目標。