需求
在每次打开界面滑动列表都是复位状态（未滑动）。
分析
在制作滑动列表时常常会结合UIPanel和UIScrollView
要让滑动列表回到未滑动时的位置，那么就需要改变Panel的Clipping和transform的position
演示
以前做法
以前是保存Panel的初始信息，每时打开面板时再还原
public class CUIShopVIP : CUIController { private UIPanel GridPanel; private UIScrollView GridPanel_ScrollView; private float BakGridPanel_Y; private Vector4 BakGridPanel_ClipRegion; public override void OnInit() { base.OnInit(); //...... 初始化代码 GridPanel = GetControl<UIPanel>("GridPanel"); GridPanel_ScrollView = GridPanel.GetComponent<UIScrollView>(); BakGridPanel_Y = GridPanel.transform.GetLocalPositionY(); BakGridPanel_ClipRegion = GridPanel.baseClipRegion; } public override void OnOpen(params object[] args) { base.OnOpen(args); //打开前 重设Scrollview的属性到初始 GridPanel.baseClipRegion = BakGridPanel_ClipRegion;//NOTE 不建议直接修改此值 GridPanel_ScrollView.UpdatePosition(); GridPanel_ScrollView.ResetPosition(); GridPanel.transform.SetLocalPositionY(BakGridPanel_Y); } }
之前的做法是 修改 Panel的 localPosition 和 Panel的 baseClipRegion，但官方不建议直接修改baseClipRegion。然后更新ScrollView的信息
/// <summary>
/// Clipping position (XY) and size (ZW).
/// Note that you should not be modifying this property at run-time to reposition the clipping. Adjust clipOffset instead.
/// </summary>
public Vector4 baseClipRegion
编写组件
现在做了一个PanelResetHelper，修改Panel的 clipOffset和 localPosition 而不直接修改baseClipRegion
/// <summary>
/// Clipping area offset used to make it possible to move clipped panels (scroll views) efficiently.
/// Scroll views move by adjusting the clip offset by one value, and the transform position by the inverse.
/// This makes it possible to not have to rebuild the geometry, greatly improving performance.
/// </summary>
public Vector2 clipOffset
原理
和之前做法一样，初始化时保存Panel的属性，界面打开时，再还原值。
组件源码
Helper代码如下
/// <summary> /// 可以对UIPanel进行滚动复位 /// </summary> public class CUIPanelResetHelper { private UIPanel _panel; private Vector2 _initPanelClipOffset; private Vector3 _initPanelLocalPos; public CUIPanelResetHelper(UIPanel uiPanel) { _panel = uiPanel; _initPanelClipOffset = _panel.clipOffset; _initPanelLocalPos = _panel.cachedTransform.localPosition; } public void ResetScroll() { _panel.clipOffset = _initPanelClipOffset; _panel.cachedTransform.localPosition = _initPanelLocalPos; } }
组件用法
public class CUIShopVIP : CUIController { private UIPanel GridPanel; private CUIPanelResetHelper GridPanelResetHelper; public override void OnInit() { base.OnInit(); //...... 初始化代码 GridPanel = GetControl<UIPanel>("GridPanel"); GridPanelResetHelper = new CUIPanelResetHelper(GridPanel); } public override void OnOpen(params object[] args) { base.OnOpen(args); //打开前 重设Scrollview的属性到初始 GridPanelResetHelper.ResetScroll(); } }
UIScrollView
uiscrollview中的属性
/// <summary> /// Whether the dragging will be restricted to be within the scroll view's bounds. /// </summary> public bool restrictWithinPanel = true; /// <summary> /// Whether dragging will be disabled if the contents fit. /// </summary> public bool disableDragIfFits = false;
