UGUI默认提供了横竖布局组件, 但有时候还需要一种扇形布局的组件,如下图:
image.png
方法1:
使用HorizontalLayoutGroup,根据规则(三角函数)用代码修改每个item的Y.
方法2:
使用C#写一个圆形(包含扇形)布局组件,以便扩展更多,代码如下:
using UnityEngine;
using UnityEngine.UI;
/// <summary>扇形布局组件</summary>
/// <author>Danny Yan</author>
[AddComponentMenu("Layout/Circle Layout Group", 150)]
public class CircleLayoutGroup : LayoutGroup
{
public enum LayoutMode
{
/// <summar>平均分布</summary>
Hypodispersion = 0,
/// <summar>扇形分布</summary>
Sector = 1,
}
[Header("分布模式: Hypodispersion(圆形平均分布) Sector(扇形分布)")]
public LayoutMode mode = LayoutMode.Hypodispersion;
[Header("半径")]
public float radius = 0;
[Header("起始角度")]
public float initAngle = 0;
[Header("是否保持弧度值不变")]
public bool keepRadLen = false;
[Header("弧度保持不变的值(keepRadLen为true时有效)")]
public float keepRadLenVal = 0f;
[Header("扇形分布范围")]
public float sectorAngle = 0;
[Header("扇形分布时且keepRadLen为false时,是否中间对齐到扇形中心,否则两端对齐")]
public bool sectorAlignCenter = false;
[Header("扇形分布且sectorAlignCenter为false时,是否为逆时针")]
public bool sectorClockwise = true;
// public float fDistance;
// [Range(0f, 360f)]
// public float MinAngle, MaxAngle, StartAngle;
protected override void OnEnable()
{
base.OnEnable();
CalculateRadial();
}
public override void SetLayoutHorizontal()
{
// Util.Print("SetLayoutHorizontal");
CalculateRadial();
}
public override void SetLayoutVertical()
{
// Util.Print("SetLayoutVertical");
CalculateRadial();
}
public override void CalculateLayoutInputHorizontal()
{
base.CalculateLayoutInputHorizontal();
// Util.Print("CalculateLayoutInputHorizontal");
CalculateRadial();
}
public override void CalculateLayoutInputVertical()
{
// Util.Print("CalculateLayoutInputVertical");
CalculateRadial();
}
#if UNITY_EDITOR
protected override void OnValidate()
{
base.OnValidate();
CalculateRadial();
}
#endif
protected void CalculateRadial()
{
this.m_Tracker.Clear();
if (transform.childCount == 0)
return;
if (this.mode == LayoutMode.Hypodispersion)
{
this.Hypodispersion();
}
else if (this.mode == LayoutMode.Sector)
{
this.Sector();
}
}
/// 平均分布
private void Hypodispersion()
{
// rectChildren来自父类,在CalculateLayoutInputHorizontal()中进行的非active和IgonreLayout的子节点剔除
if (this.rectChildren.Count <= 0) return;
float perRad = 2 * Mathf.PI / rectChildren.Count;
// float perAngle = 360 / rectChildren.Count;
float initRad = this.initAngle * Mathf.Deg2Rad;
this.SetLayout(initRad, perRad);
}
/// 扇形分布
private void Sector()
{
if (rectChildren.Count <= 0) return;
float perRad = 0;
float initRad = this.initAngle * Mathf.Deg2Rad;
// 扇形弧度
var sectorRad = this.sectorAngle * Mathf.Deg2Rad;
if (this.keepRadLen)
{
// 弧长公式为: L = (angle * PI / 180) * radius = rad * radius, 要保持弧长不变,则需要改变rad即可, rad = L / radius
perRad = keepRadLenVal / this.radius;
if (sectorAlignCenter)
{
// 将initRad重置到sectorRad中线上
initRad += (sectorClockwise ? sectorRad * .5f : -sectorRad * .5f);
if (rectChildren.Count > 1)
{
// 根据数量重置initRad
float _radOff = perRad * ((rectChildren.Count - 1) * 0.5f);
initRad -= (sectorClockwise ? _radOff : -_radOff);
}
}
else
{
perRad = keepRadLenVal / this.radius;
}
}
else
{
// 居中对齐到扇形中心
if (sectorAlignCenter)
{
perRad = sectorRad / (rectChildren.Count + 1);
initRad += sectorClockwise ? perRad : -perRad;
}
else
{
perRad = rectChildren.Count == 1 ? 0 : sectorRad / (rectChildren.Count - 1);
}
}
if (!sectorClockwise)
{
perRad *= -1;
}
this.SetLayout(initRad, perRad);
}
private void SetLayout(float initRad, float perRad)
{
// 计算最佳大小
float totalMin = 0;
float totalPreferred = 0;
float totalFlexible = 0;
float minX = float.MaxValue;
float maxX = float.MinValue;
float minY = float.MaxValue;
float maxY = float.MinValue;
for (int i = 0; i < rectChildren.Count; i++)
{
var child = rectChildren[i];
//禁用子节点recttransform相关属性
m_Tracker.Add(this, child,
DrivenTransformProperties.Anchors |
DrivenTransformProperties.AnchoredPosition |
DrivenTransformProperties.Pivot);
var size = child.rect.size;
child.pivot = new Vector2(0.5f, 0.5f);
child.anchorMin = new Vector2(0.5f, 0.5f);
child.anchorMax = new Vector2(0.5f, 0.5f);
child.SetSizeWithCurrentAnchors(RectTransform.Axis.Horizontal, size.x);
child.SetSizeWithCurrentAnchors(RectTransform.Axis.Vertical, size.y);
// child.SetInsetAndSizeFromParentEdge(RectTransform.Edge.Left, -pSize.x*.5f, size.x);
// child.SetInsetAndSizeFromParentEdge(RectTransform.Edge.Top, -pSize.y*.5f, size.y);
// child.SetInsetAndSizeFromParentEdge(RectTransform.Edge.Left | RectTransform.Edge.Right, size.x*.5f, size.x);
// child.SetInsetAndSizeFromParentEdge(RectTransform.Edge.Top | RectTransform.Edge.Bottom, size.y*.5f, size.y);
// float min, preferred, flexible;
// GetChildSizes(child, 0, out min, out preferred, out flexible);
// size.x = LayoutUtility.GetMinSize(child, 0);
// size.y = LayoutUtility.GetMinSize(child, 1);
size *= 0.5f * child.localScale;
Vector3 vPos = child.localPosition;
var rad = initRad + perRad * i;
vPos.x = this.radius * Mathf.Cos(rad);
vPos.y = this.radius * Mathf.Sin(rad);
child.localPosition = vPos;
var left = vPos.x - size.x;
if (left < minX) minX = left;
var right = vPos.x + size.x;
if (right > maxX) maxX = right;
var bottom = vPos.y - size.y;
if (bottom < minY) minY = bottom;
var top = vPos.y + size.y;
if (top > maxY) maxY = top;
}
// 此处宽高计算并不是很精确
var w = Mathf.Abs(maxX - minX);
var h = Mathf.Abs(maxY - minY);
totalMin = this.radius;
totalPreferred = w;
if (this.mode == LayoutMode.Sector)
{
// totalPreferred += radius;
}
SetLayoutInputForAxis(totalMin, totalPreferred, totalFlexible, 0);
totalPreferred = h;
if (this.mode == LayoutMode.Sector)
{
// totalPreferred += radius;
}
SetLayoutInputForAxis(totalMin, totalPreferred, totalFlexible, 1);
}
}
说明:
- 继承自LayoutGroup,在SetLayoutXX()和CalculateLayoutInputXX()方法中直接调用CalculateRadial()进行计算,Layout提供的Padding和Child Alignment不生效;
- 提供圆形布局和扇形布局2种模式,圆形布局较为简单,扇形布局提供更多的效果方式,半径和起始角度是通用的;
-
圆形布局只能平均分布,效果图如下:
image.png
- 扇形模式下必须设置分布角度(sectorAngle值),同时分为普通扇形平均分布和强制弧度长度不变分布:
扇形模式下的效果对比:
普通平均分布:
image.png
image.png
改变半径,间距变大
强制保持弧度长度:
image.png
image.png
改变半径,item之间的弧度长度不变
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