unity3d - 根据 Horizo​​ntalLayoutGroup 等，更正 Unity3D 中的 'FlowLayoutGroup'

Question

说你要普通冲洗左流在 Unity 用户界面中。例子:


其实回答THIS question我已经实现了“艰难的方式”同花顺左流。在 Unity 自动布局中设置“垂直行组”，在顶层附加 FattieFlow，

public class FattieFlow : MonoBehaviour
{
    public GameObject modelRow;
    public GameObject modelItem;
    public void Flow()
    {
        screen = GetComponent<RectTransform>().rect.width;

        // move downwards any which need to be moved downwards
        int row = 0;
        while (row < transform.childCount)  // (dynamic)
        {
            if (transform.GetChild(row).gameObject.activeSelf) FlowRow(row);
            ++row;
        }
        // et cetera....
    }
}

FattieFlow将完全重新流动它与左齐平(通过操纵线条，艰难的方式)。这是一个脚本、演示等: the hard way .
但这是一个糟糕的解决方案。
理想情况下，从
UI.HorizontalLayoutGroup和 UI.VerticalLayoutGroup
应该可以创建 FlowLayoutGroup布局，向左齐平，进入一个街区。 (事实上​​，它应该根据需要扩展块，依此类推……与 HorizontalLayoutGroup 的行为完全一样)。
看来您必须从 HorizontalOrVerticalLayoutGroup 开始并从那里开始工作。
如何做到这一点(如果它不存在 已经存在 )？

Answer 1

到目前为止，我想出了这个:

FlowLayoutGroup

using UnityEngine;
using System.Collections;
using UnityEngine.UI;

[AddComponentMenu("Layout/Flow Layout Group", 153)]
public class FlowLayoutGroup : LayoutGroup
{
    public enum Corner { 
        UpperLeft = 0, 
        UpperRight = 1, 
        LowerLeft = 2, 
        LowerRight = 3 
    }

    public enum Constraint { 
        Flexible = 0, 
        FixedColumnCount = 1, 
        FixedRowCount = 2 
    }

    protected Vector2 m_CellSize = new Vector2(100, 100);
    public Vector2 cellSize { 
        get { return m_CellSize; } 
        set { SetProperty(ref m_CellSize, value); } 
    }

    [SerializeField] protected Vector2 m_Spacing = Vector2.zero;
    public Vector2 spacing { 
        get { return m_Spacing; } 
        set { SetProperty(ref m_Spacing, value); } 
    }

    protected FlowLayoutGroup()
    {}

#if UNITY_EDITOR
    protected override void OnValidate()
    {
        base.OnValidate();
    }

#endif

    public override void CalculateLayoutInputHorizontal()
    {
        base.CalculateLayoutInputHorizontal();

        int minColumns = 0;
        int preferredColumns = 0;

        minColumns = 1;
        preferredColumns = Mathf.CeilToInt(Mathf.Sqrt(rectChildren.Count));

        SetLayoutInputForAxis(
            padding.horizontal + (cellSize.x + spacing.x) * minColumns - spacing.x,
            padding.horizontal + (cellSize.x + spacing.x) * preferredColumns - spacing.x,
            -1, 0);
    }

    public override void CalculateLayoutInputVertical()
    {
        int minRows = 0;

        float width = rectTransform.rect.size.x;
        int cellCountX = Mathf.Max(1, Mathf.FloorToInt((width - padding.horizontal + spacing.x + 0.001f) / (cellSize.x + spacing.x)));
//      minRows = Mathf.CeilToInt(rectChildren.Count / (float)cellCountX);
        minRows = 1;
        float minSpace = padding.vertical + (cellSize.y + spacing.y) * minRows - spacing.y;
        SetLayoutInputForAxis(minSpace, minSpace, -1, 1);
    }

    public override void SetLayoutHorizontal()
    {
        SetCellsAlongAxis(0);
    }

    public override void SetLayoutVertical()
    {
        SetCellsAlongAxis(1);
    }

    int cellsPerMainAxis, actualCellCountX, actualCellCountY;
    int positionX;
    int positionY;
    float totalWidth = 0; 
    float totalHeight = 0;

    float lastMaxHeight = 0;

    private void SetCellsAlongAxis(int axis)
    {
        // Normally a Layout Controller should only set horizontal values when invoked for the horizontal axis
        // and only vertical values when invoked for the vertical axis.
        // However, in this case we set both the horizontal and vertical position when invoked for the vertical axis.
        // Since we only set the horizontal position and not the size, it shouldn't affect children's layout,
        // and thus shouldn't break the rule that all horizontal layout must be calculated before all vertical layout.

        float width = rectTransform.rect.size.x;
        float height = rectTransform.rect.size.y;

        int cellCountX = 1;
        int cellCountY = 1;

        if (cellSize.x + spacing.x <= 0)
            cellCountX = int.MaxValue;
        else
            cellCountX = Mathf.Max(1, Mathf.FloorToInt((width - padding.horizontal + spacing.x + 0.001f) / (cellSize.x + spacing.x)));

        if (cellSize.y + spacing.y <= 0)
            cellCountY = int.MaxValue;
        else
            cellCountY = Mathf.Max(1, Mathf.FloorToInt((height - padding.vertical + spacing.y + 0.001f) / (cellSize.y + spacing.y)));

        cellsPerMainAxis = cellCountX;
        actualCellCountX = Mathf.Clamp(cellCountX, 1, rectChildren.Count);
        actualCellCountY = Mathf.Clamp(cellCountY, 1, Mathf.CeilToInt(rectChildren.Count / (float)cellsPerMainAxis));

        Vector2 requiredSpace = new Vector2(
            actualCellCountX * cellSize.x + (actualCellCountX - 1) * spacing.x,
            actualCellCountY * cellSize.y + (actualCellCountY - 1) * spacing.y
        );
        Vector2 startOffset = new Vector2(
            GetStartOffset(0, requiredSpace.x),
            GetStartOffset(1, requiredSpace.y)
        );

        totalWidth = 0;
        totalHeight = 0;
        Vector2 currentSpacing = Vector2.zero;
        for (int i = 0; i < rectChildren.Count; i++)
        {
            SetChildAlongAxis(rectChildren[i], 0, startOffset.x + totalWidth /*+ currentSpacing[0]*/, rectChildren[i].rect.size.x);
            SetChildAlongAxis(rectChildren[i], 1, startOffset.y + totalHeight  /*+ currentSpacing[1]*/, rectChildren[i].rect.size.y);

            currentSpacing = spacing;

            totalWidth += rectChildren[i].rect.width + currentSpacing[0];

            if (rectChildren[i].rect.height > lastMaxHeight)
            {
                lastMaxHeight = rectChildren[i].rect.height;
            }

            if (i<rectChildren.Count-1)
            {
                if (totalWidth + rectChildren[i+1].rect.width + currentSpacing[0] > width )
                {
                    totalWidth = 0;
                    totalHeight += lastMaxHeight + currentSpacing[1];
                    lastMaxHeight = 0;
                }
            }
        }
    }
}

如何使用

将此脚本附加到您的面板，就像您使用其他布局组(如 GridViewLayout

)一样

添加 UI 元素(按钮、图像等)作为面板的子元素。

添加 ContentSizeFitter子组件并设置 Horizontal Fit和 Vertical Fit属性到 首选尺寸

添加 Layout Element组件到子组件并设置 Preferred Width和 Preferred Height值。这些值将控制 UI 元素的大小。您也可以使用 Min Width和 Min Height反而。

添加任意数量的元素并应用相同的程序以获得所需的大小。

这是在检查器窗口中的样子:



用不同尺寸的按钮测试过，效果很好。



注意:

我修改了 GridLayoutGroup从 Unity UI 代码中获取所需的类
行为。因为它源自 LayoutGroup哪个控制
child RectTransform特性。我们需要使用ContentSizeFitter和 LayoutElement在 child 改变他们的
尺寸。

与 GridLayout 不同，它仅适用于从左上角开始的水平流。这允许从垂直开始并从其他角落开始。我不认为这是一个限制，因为这只是 可以预期的行为。流布局组 .

我还添加了一个 Repository on GithHub如果有人想为此做出贡献。

谢谢!