一.首先点击UI创建两个Image，将Image的Source Image改成自己想要的Texture即可，然后在Canvas下创建一空物体，将两个Image放在空物体下作为他的子对象；

然后为可以拖动的Image编写脚本，脚本如下：（有注释，就不多说了）

using UnityEngine;
using System.Collections;
using UnityEngine.UI;
using UnityEngine.EventSystems;public class JoyStick : MonoBehaviour, IPointerDownHandler, IPointerUpHandler, IDragHandler//需要注意继承的接口，接口内的方法需要实现
{/// <summary>/// 摇杆最大半径/// 以像素为单位/// </summary>public float JoyStickRadius = 50;/// <summary>/// 摇杆重置所诉/// </summary>public float JoyStickResetSpeed = 5.0f;/// <summary>/// 当前物体的Transform组件/// </summary>private RectTransform selfTransform;/// <summary>/// 是否触摸了虚拟摇杆/// </summary>private bool isTouched = false;/// <summary>/// 虚拟摇杆的默认位置/// </summary>private Vector2 originPosition;/// <summary>/// 虚拟摇杆的移动方向/// </summary>private Vector2 touchedAxis;public Vector2 TouchedAxis{get{if (touchedAxis.magnitude < JoyStickRadius)return touchedAxis.normalized / JoyStickRadius;return touchedAxis.normalized;}}/// <summary>/// 定义触摸开始事件委托 /// </summary>public delegate void JoyStickTouchBegin(Vector2 vec);/// <summary>/// 定义触摸过程事件委托 /// </summary>/// <param name="vec">虚拟摇杆的移动方向</param>public delegate void JoyStickTouchMove(Vector2 vec);/// <summary>/// 定义触摸结束事件委托/// </summary>public delegate void JoyStickTouchEnd();/// <summary>/// 注册触摸开始事件/// </summary>public event JoyStickTouchBegin OnJoyStickTouchBegin;/// <summary>/// 注册触摸过程事件/// </summary>public event JoyStickTouchMove OnJoyStickTouchMove;/// <summary>/// 注册触摸结束事件/// </summary>public event JoyStickTouchEnd OnJoyStickTouchEnd;void Start(){//初始化虚拟摇杆的默认方向selfTransform = this.GetComponent<RectTransform>();originPosition = selfTransform.anchoredPosition;}public void OnPointerDown(PointerEventData eventData){isTouched = true;touchedAxis = GetJoyStickAxis(eventData);if (this.OnJoyStickTouchBegin != null)this.OnJoyStickTouchBegin(TouchedAxis);}public void OnPointerUp(PointerEventData eventData){isTouched = false;selfTransform.anchoredPosition = originPosition;touchedAxis = Vector2.zero;if (this.OnJoyStickTouchEnd != null)this.OnJoyStickTouchEnd();}public void OnDrag(PointerEventData eventData){touchedAxis = GetJoyStickAxis(eventData);if (this.OnJoyStickTouchMove != null)this.OnJoyStickTouchMove(TouchedAxis);}void Update(){//当虚拟摇杆移动到最大半径时摇杆无法拖动//为了确保被控制物体可以继续移动//在这里手动触发OnJoyStickTouchMove事件if (isTouched && touchedAxis.magnitude >= JoyStickRadius){if (this.OnJoyStickTouchMove != null)this.OnJoyStickTouchMove(TouchedAxis);}//松开虚拟摇杆后让虚拟摇杆回到默认位置if (selfTransform.anchoredPosition.magnitude > originPosition.magnitude)selfTransform.anchoredPosition -= TouchedAxis * Time.deltaTime * JoyStickResetSpeed;}/// <summary>/// 返回虚拟摇杆的偏移量/// </summary>/// <returns>The joy stick axis.</returns>/// <param name="eventData">Event data.</param>private Vector2 GetJoyStickAxis(PointerEventData eventData){//获取手指位置的世界坐标Vector3 worldPosition;if (RectTransformUtility.ScreenPointToWorldPointInRectangle(selfTransform,eventData.position, eventData.pressEventCamera, out worldPosition))selfTransform.position = worldPosition;//获取摇杆的偏移量Vector2 touchAxis = selfTransform.anchoredPosition - originPosition;//摇杆偏移量限制if (touchAxis.magnitude >= JoyStickRadius){touchAxis = touchAxis.normalized * JoyStickRadius;selfTransform.anchoredPosition = touchAxis;}return touchAxis;}}

二.接下来，就是拖拽p_w_picpath使物体能够移动了；

为该物体添加脚本：

using UnityEngine;
using System.Collections;public class JoyStick3D : MonoBehaviour
{private JoyStick js;void Start(){js = GameObject.FindObjectOfType<JoyStick>();js.OnJoyStickTouchBegin += OnJoyStickBegin;js.OnJoyStickTouchMove += OnJoyStickMove;js.OnJoyStickTouchEnd += OnJoyStickEnd;}void OnJoyStickBegin(Vector2 vec){Debug.Log("开始触摸虚拟摇杆");}void OnJoyStickMove(Vector2 vec){Debug.Log("正在移动虚拟摇杆");//设置角色朝向Quaternion q = Quaternion.LookRotation(new Vector3(vec.x, 0, vec.y));transform.rotation = q;//移动角色transform.Translate(Vector3.forward * 75f * Time.deltaTime);}void OnJoyStickEnd(){Debug.Log("触摸移动摇杆结束");}void OnGUI(){GUI.Label(new Rect(30, 30, 200, 30), "3D模式下的虚拟摇杆测试");}
}

三.接着可以试着运行，可以看到物体可以随着p_w_picpath的拖动而移动，但是有不好的地方，就是拖拽的p_w_picpath超过半径所设置的半径JoyStickRadius时，p_w_picpath的位置就会固定在一个位置不动，

而且当在半径范围内时，物体不会持续移动，这个就不好了，不知道有那位大神能够邦杰呢？