unity多点触控android 2D

我正在制作一款游戏，主角可以跳跃，向左移动&正确的。我有一个问题。多点触控不能用。我正在使用c#，我已经在互联网上到处搜索，我还没有找到答案。

my code:

using UnityEngine;
using System.Collections;
[RequireComponent(typeof (Rigidbody2D))]
[RequireComponent(typeof(BoxCollider2D))]
public class TouchControls : MonoBehaviour {
    // GUI textures
    public GUITexture guiLeft;
    public GUITexture guiRight;
    public GUITexture guiJump;
    // Movement variables
    public float moveSpeed = 5f;
    public float jumpForce = 50f;
    public float maxJumpVelocity = 2f;
    // Movement flags
    private bool moveLeft, moveRight, doJump = false;
    // Update is called once per frame
    void Update () {
        // Check to see if the screen is being touched
        if (Input.touchCount > 0)
        {
            // Get the touch info
            Touch t = Input.GetTouch(0);
            // Did the touch action just begin?
            if (t.phase == TouchPhase.Began)
            {
                // Are we touching the left arrow?
                if (guiLeft.HitTest(t.position, Camera.main))
                {
                    Debug.Log("Touching Left Control");
                    moveLeft = true;
                }
                // Are we touching the right arrow?
                if (guiRight.HitTest(t.position, Camera.main))
                {
                    Debug.Log("Touching Right Control");
                    moveRight = true;
                }
                // Are we touching the jump button?
                if (guiJump.HitTest(t.position, Camera.main))
                {
                    Debug.Log("Touching Jump Control");
                    doJump = true;
                }
            }
            // Did the touch end?
            if (t.phase == TouchPhase.Ended)
            {
                // Stop all movement
                doJump = moveLeft = moveRight = false;
                rigidbody2D.velocity = Vector2.zero;
            }
        }
        // Is the left mouse button down?
        if (Input.GetMouseButtonDown(0))
        {
            // Are we clicking the left arrow?
            if (guiLeft.HitTest(Input.mousePosition, Camera.main))
            {
                Debug.Log("Touching Left Control");
                moveLeft = true;
            }
            // Are we clicking the right arrow?
            if (guiRight.HitTest(Input.mousePosition, Camera.main))
            {
                Debug.Log("Touching Right Control");
                moveRight = true;
            }
            // Are we clicking the jump button?
            if (guiJump.HitTest(Input.mousePosition, Camera.main))
            {
                Debug.Log("Touching Jump Control");
                doJump = true;
            }
        }
        if (Input.GetMouseButtonUp(0))
        {
            // Stop all movement on left mouse button up
            doJump = moveLeft = moveRight = false;
            rigidbody2D.velocity = Vector2.zero;
        }
    }
    void FixedUpdate()
    {
        // Set velocity based on our movement flags.
        if (moveLeft)
        {
            rigidbody2D.velocity = -Vector2.right * moveSpeed;
        }
        if (moveRight)
        {
            rigidbody2D.velocity = Vector2.right * moveSpeed;
        }
        if (doJump)
        {
            // If we have not reached the maximum jump velocity, keep applying force.
            if (rigidbody2D.velocity.y < maxJumpVelocity)
            {
                rigidbody2D.AddForce(Vector2.up * jumpForce);
            } else {
                // Otherwise stop jumping
                doJump = false;
            }
        }
    }
}

if (Input.touchCount > 0) {
    for(int i = 0; i < Input.touchCount; i++) {
        Touch t = Input.GetTouch(0);
        ..
        ..
}

using UnityEngine;
using System.Collections;
[RequireComponent(typeof (Rigidbody2D))]
[RequireComponent(typeof(BoxCollider2D))]
public class TouchControls : MonoBehaviour {
public GUITexture guiLeft;
public GUITexture guiRight;
public GUITexture guiJump;
public float moveSpeed = 5f;
public float jumpForce = 50f;
public float maxJumpVelocity = 2f;
private bool moveLeft, moveRight, doJump = false;
void Update () {
    if (Input.touchCount > 0) {
        for(int i = 0; i < Input.touchCount; i++) {
            Touch t = Input.GetTouch(i);
            if (t.phase == TouchPhase.Began) {
                if (guiLeft.HitTest(t.position, Camera.main)) {
                    Debug.Log("Touching Left Control");
                    moveLeft = true;
                }
                if (guiRight.HitTest(t.position, Camera.main)) {
                    Debug.Log("Touching Right Control");
                    moveRight = true;
                }
                // Are we touching the jump button?
                if (guiJump.HitTest(t.position, Camera.main)) {
                    Debug.Log("Touching Jump Control");
                    doJump = true;
                }
            }
            if (t.phase == TouchPhase.Ended) {
                // Stop all movement
                doJump = moveLeft = moveRight = false;
                rigidbody2D.velocity = Vector2.zero;
            }
        }
    }
    if (Input.GetMouseButtonDown(0)) {
        if (guiLeft.HitTest(Input.mousePosition, Camera.main)) {
            Debug.Log("Touching Left Control");
            moveLeft = true;
        }
        if (guiRight.HitTest(Input.mousePosition, Camera.main)) {
            Debug.Log("Touching Right Control");
            moveRight = true;
        }
        if (guiJump.HitTest(Input.mousePosition, Camera.main)) {
            Debug.Log("Touching Jump Control");
            doJump = true;
        }
    }
    if (Input.GetMouseButtonUp(0)) {
        doJump = moveLeft = moveRight = false;
        rigidbody2D.velocity = Vector2.zero;
    }
}
void FixedUpdate() {
    if (moveLeft) {
        rigidbody2D.velocity = -Vector2.right * moveSpeed;
    }
    if (moveRight) {
        rigidbody2D.velocity = Vector2.right * moveSpeed;
    }
    if (doJump) {
        if (rigidbody2D.velocity.y < maxJumpVelocity) {
            rigidbody2D.AddForce(Vector2.up * jumpForce);
        } else {
            doJump = false;
        }
    }
}
}