1、获取屏幕输入

新建脚本TouchInput，添加到MainCamera(主摄像机)上

public class TouchInput : MonoBehaviour
{
    public LayerMask touchInputMask;  //声明层级，射线只与设定的层级进行检测
    private Camera myCamera;          //声明摄像机

    private List<GameObject> touchList = new List<GameObject>();    //保存当前按下的物体，需要用List进行动态添加
    private GameObject[] touchesOld; //保存上一次按下的物体，不需要动态添加，与当前按下的物体比较，判断哪些物体取消了点击
    private RaycastHit hit;
    void Start()
    {
        myCamera = GetComponent<Camera>();
    }
    void Update()
    {
        if (Input.touchCount > 0)   //如果存在触屏输入
        {
            //初始化touchesOld，并保存上一帧按下的所有按键
            touchesOld = new GameObject[touchList.Count];
            touchList.CopyTo(touchesOld);
            touchList.Clear();  //清空列表，用于获取新的输入，保存当前按下的物体

            foreach (Touch touch in Input.touches)  //遍历所有的屏触屏输入
            {
                Ray ray = myCamera.ScreenPointToRay(touch.position);    //从触屏的地方发射射线

                if (Physics.Raycast(ray, out hit, touchInputMask))
                {
                    GameObject recipient = hit.transform.gameObject;    //获取射线碰撞的物体
                    touchList.Add(recipient);     //将该物体加入当前触碰列表

                    if (touch.phase == TouchPhase.Began)    //判断触屏的类型，如果为刚刚接触屏幕
                    {
                        //发送委托，调用物体OnTouchDown的方法
                        recipient.SendMessage("OnTouchDown", hit.point, SendMessageOptions.DontRequireReceiver);
                    }
                    if (touch.phase == TouchPhase.Ended)    //判断触屏的类型，如果手指离开屏幕
                    {
                        //发送委托，调用物体OnTouchUp的方法
                        recipient.SendMessage("OnTouchUp", hit.point, SendMessageOptions.DontRequireReceiver);
                    }
                    //如果长按屏幕或在屏幕上滑动
                    if (touch.phase == TouchPhase.Stationary || touch.phase == TouchPhase.Moved)    
                    {
                        //发送委托，调用物体OnTouchStay的方法
                        recipient.SendMessage("OnTouchStay", hit.point, SendMessageOptions.DontRequireReceiver);
                    }
                    if (touch.phase == TouchPhase.Canceled) //如果手指数量超过追踪上线，或用脸等平面接触屏幕
                    {
                        //发送委托，调用物体OnTouchExit的方法
                        recipient.SendMessage("OnTouchExit", hit.point, SendMessageOptions.DontRequireReceiver);
                    }
                }
            }
            foreach (GameObject g in touchesOld)    //遍历上一帧点击的物体
            {
                if (!touchList.Contains(g))         //如果列表中不包含上一帧的物体
                {
                    //那么委托调用物体的OnTouchExit方法，该物已经取消点击
                    g.SendMessage("OnTouchExit", hit.point, SendMessageOptions.DontRequireReceiver);
                }
            }
        }
    }
}

新建脚本Button

public class Button : MonoBehaviour
{
    public Color defaultColor;	//默认颜色
    public Color selectedColor;	//点击后的颜色
    private Material mat;
    private void Start()
    {
        mat = gameObject.GetComponent<Renderer>().material;
    }
    private void OnTouchDown()
    {
        mat.color = selectedColor;
    }
    private void OnTouchUp()
    {
        mat.color = defaultColor;
    }
    private void OnTouchStay()
    {
        mat.color = selectedColor;
    }
    private void OnTouchExit()
    {
        mat.color = defaultColor;
    }
}

添加几个Cube，将Button添加到Cube上

设置每个Cube的颜色
Build到手机后的运行结果

2、拖动效果

这里的Slider并不是UnityUI中的Slider

是使用基本物体拼装成的Slider

这里使用了3D物体中的Quad和Cube


然后可以在 Slider上创建一个BoxCollider 来限制Button的移动

新建脚本Slider

public class Slider : MonoBehaviour
{
    public Transform button;
    private Vector3 targetPos;
    private void Start()
    {
        targetPos = button.position;
    }
    private void Update()
    {
        button.position = Vector3.Lerp(button.position, targetPos, Time.deltaTime * 10f);
    }
    void OnTouchStay(Vector3 point)
    {
        targetPos = new Vector3(point.x, targetPos.y, targetPos.z);
    }
}

然后将Button添加到Button上

运行后就能拖动Button

接下来是显示数据，添加一个3DText设为Slider的子物体，并调整到合适的位置和大小

新建脚本Slider，添加到Slider上

public class Slider : MonoBehaviour
{
    public Transform knbo;
    public TextMesh textMesh;
    private Vector3 targetPos;

    private float sliderPercent;
    private float sliderLength;

    private void Start()
    {
        sliderLength = gameObject.GetComponent<BoxCollider>().size.x - 0.4f;
        targetPos = knbo.position;
    }
    private void Update()
    {
        knbo.position = Vector3.Lerp(knbo.position, targetPos, Time.deltaTime * 10f);
		//计算slider的比例
        sliderPercent = Mathf.Clamp01((knbo.localPosition.x + sliderLength / 2) / sliderLength);
													//保留一位小数
        textMesh.text = string.Format(sliderName + ": " + "{0:F1}", sliderPercent);	
    }
    public float GetSliderPercent()
    {
        return sliderPercent;
    }
    void OnTouchStay(Vector3 point)
    {
        targetPos = new Vector3(point.x, targetPos.y, targetPos.z);
    }
}