NGUI例子Scroll View场景中item添加点击后自动滑到终点

http://blog.csdn.net/luyuncsd123/article/details/22914497

最近在做一个项目的UI，需求是1、拖动items后当永远有一个item保存在中间位置，、点击当前item后当前item滑动到终点。 

咱看了NGUI的Scroll View例子后发现第一个要求NGUI自带了，第二个要求没有，所以自己写了个包含这2个需求的脚本。 

把相应的脚本替换成这几个就可以了。如果碰到变量保护之类的错误的话把父类中的方法改成protected就行了。 

using UnityEngine;
using System.Collections; 

[ExecuteInEditMode]
public class QRCUICenterOnChild : UICenterOnChild
{
    private Transform moveTarget; 

    protected QRCUIDraggablePanel mQrcDrag; 

    void OnEnable() { Recenter(null); //Recenter();
    } 

    void OnDragFinished(GameObject obj)
    {
        if (enabled)
        {
            //if (obj != null)
                Recenter(obj);
            //else
            //    Recenter();
        }
    } 

    /// <summary>
    /// Recenter the draggable list on the center-most child.
    /// </summary> 

    public void Recenter(GameObject obj)
    {
        if (mQrcDrag == null)
        {
            mQrcDrag = NGUITools.FindInParents<qrcuidraggablepanel>(gameObject); 

            if (mQrcDrag == null)
            {
                Debug.LogWarning(GetType() + " requires " + typeof(QRCUIDraggablePanel) + " on a parent object in order to work", this);
                enabled = false;
                return;
            }
            else
            {
                mQrcDrag.onDragFinished = OnDragFinished; 

                //if (mDrag.horizontalScrollBar != null)
                //    mDrag.horizontalScrollBar.onDragFinished = OnDragFinished; 

                //if (mDrag.verticalScrollBar != null)
                //    mDrag.verticalScrollBar.onDragFinished = OnDragFinished;
            }
        }
        if (mQrcDrag.panel == null) return; 

        // Calculate the panel's center in world coordinates
        Vector4 clip = mQrcDrag.panel.clipRange;
        Transform dt = mQrcDrag.panel.cachedTransform;
        Vector3 center = dt.localPosition;
        center.x += clip.x;
        center.y += clip.y;
        center = dt.parent.TransformPoint(center); 

        // Offset this value by the momentum
        Vector3 offsetCenter = center - mQrcDrag.currentMomentum * (mQrcDrag.momentumAmount * 0.1f);
        mQrcDrag.currentMomentum = Vector3.zero; 

        float min = float.MaxValue;
        Transform closest = null;
        Transform trans = transform; 

        //Determine whether the user is to click on or drag
        if (obj != null)
        {
            closest = obj.transform;
        }
        else {
            closest = DetermineCloestChild(trans, offsetCenter, min, closest);
        } 

        // Spring the panel to this calculated position
        MoveTargetPosition(closest, dt, center);
    } 

    /// <summary>
    /// Determine the closest child
    /// </summary>
    public Transform DetermineCloestChild(Transform trans, Vector3 offsetCenter, float min, Transform closest)
    {
        for (int i = , imax = trans.childCount; i < imax; ++i)
        {
            Transform t = trans.GetChild(i);
            float sqrDist = Vector3.SqrMagnitude(t.position - offsetCenter); 

            if (sqrDist < min)
            {
                min = sqrDist;
                closest = t;
            }
        }
        return closest;
    } 

    /// <summary>
    /// Spring the panel to this calculated position
    /// </summary>
    public void MoveTargetPosition(Transform closest, Transform dt, Vector3 center)
    {
        if (closest != null)
        {
            mCenteredObject = closest.gameObject; 

            // Figure out the difference between the chosen child and the panel's center in local coordinates
            Vector3 cp = dt.InverseTransformPoint(closest.position);
            Vector3 cc = dt.InverseTransformPoint(center);
            Vector3 offset = cp - cc; 

            // Offset shouldn't occur if blocked by a zeroed-out scale
            if (mQrcDrag.scale.x == 0f) offset.x = 0f;
            if (mQrcDrag.scale.y == 0f) offset.y = 0f;
            if (mQrcDrag.scale.z == 0f) offset.z = 0f; 

            // Spring the panel to this calculated position
            SpringPanel.Begin(mQrcDrag.gameObject, dt.localPosition - offset, 8f).onFinished = OnQrcFisished;
        }
        else mCenteredObject = null;
    } 

    public delegate void OnQrcMoveToTragetFisished(GameObject obj);
    public event OnQrcMoveToTragetFisished OnQrcMoveToTragetFisishedHandler;
    /// <summary>
    /// After reaching the target this method will be used.
    /// </summary>
    public void OnQrcFisished() {
        OnQrcMoveToTragetFisishedHandler(mCenteredObject);
    } 

} 

==================================================分割线================================================== 

using UnityEngine;using System.Collections; 

[ExecuteInEditMode]
[RequireComponent(typeof(UIPanel))]public class QRCUIDraggablePanel : UIDraggablePanel
{ 

    public delegate void OnDragFinished(GameObject obj); 

    /// <summary>    /// Event callback to trigger when the drag process finished. Can be used for additional effects, such as centering on some object.
    /// </summary> 

    public OnDragFinished onDragFinished; 

    public void Press(bool pressed, GameObject obj)
    {        if (enabled && NGUITools.GetActive(gameObject))
        {            if (!pressed && mDragID == UICamera.currentTouchID) mDragID = -; 

            mCalculatedBounds = false;
            mShouldMove = shouldMove;            if (!mShouldMove) return;
            mPressed = pressed; 

            if (pressed)            {
                // Remove all momentum on press                mMomentum = Vector3.zero;
                mScroll = 0f; 

                // Disable the spring movement                DisableSpring(); 

                // Remember the hit position
                mLastPos = UICamera.lastHit.point; 

                // Create the plane to drag along                mPlane = new Plane(mTrans.rotation * Vector3.back, mLastPos);
            }            else
            {                if (restrictWithinPanel && mPanel.clipping != UIDrawCall.Clipping.None && dragEffect == DragEffect.MomentumAndSpring)
                {                    RestrictWithinBounds(false);
                }                if (onDragFinished != null) onDragFinished(obj);
            }        }
    }} 

===============================================分割线================================================ 

using UnityEngine;using System.Collections; 

[ExecuteInEditMode]
public class QRCUIDragPanelContents : UIDragPanelContents{ 

    private Vector3 previousTouch; 

    /// <summary>
    /// Create a plane on which we will be performing the dragging.    /// </summary>
    protected void OnPress(bool pressed)    {
        bool isClick = false;        Vector3 currentPos = Vector3.zero; 

        //Judge runtime platform
        if (Application.platform == RuntimePlatform.IPhonePlayer || Application.platform == RuntimePlatform.Android)        {
            if (Input.touchCount > )            {
                currentPos = Input.GetTouch().position;            }
        }        else {
            currentPos = Input.mousePosition;        } 

        //Calculation is click ?
        if (pressed)        {
            previousTouch = currentPos;        }
        else {            if (Vector3.Distance(previousTouch, currentPos) < 20.0f) { isClick = true; }
        } 

        if (enabled && NGUITools.GetActive(gameObject) && draggablePanel != null)        {
            QRCUIDraggablePanel qrcDraggablePanel = draggablePanel as QRCUIDraggablePanel;
            if (isClick)            {
                qrcDraggablePanel.Press(false, gameObject);            }
            else {                qrcDraggablePanel.Press(pressed, null);
            }        } 

        isClick = false;
    } 

    private bool IsClick() {        if (Application.platform == RuntimePlatform.IPhonePlayer || Application.platform == RuntimePlatform.Android) {
            if (Input.touchCount > )            {
                previousTouch = Input.GetTouch().position;            }
        }        return true;
    } 

    //protected void OnClick()    //{
    //    if (enabled && NGUITools.GetActive(gameObject) && draggablePanel != null)    //    {
    //        QRCUIDraggablePanel qrcDraggablePanel = draggablePanel as QRCUIDraggablePanel;    //        qrcDraggablePanel.Press(false, gameObject);
    //    }    //} 

}