NGUI例子Scroll View场景中item添加点击后自动滑到终点

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，2、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 = 0, 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);
}

}

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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 = -10;

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);
}        }
}}

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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 > 0)            {
currentPos = Input.GetTouch(0).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 > 0)            {
previousTouch = Input.GetTouch(0).position;            }
}        return true;
}

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

}