Unity 编辑器扩展 粒子系统批量修改属性

今天遇到一个需求,需要批量修改粒子系统的startDelay属性值,Unity编辑器本来支持多选然后赋值,但是现在需要是要在原有的值上加(+)一个值.于是就想到自己扩展下编辑器支持这个操作.

代码如下:

using UnityEngine;
using UnityEditor;

public class EffectEditorEx : EditorWindow
{
    private static EffectEditorEx m_editor_ex;

    [MenuItem("Duole/EffectEditorEx/Open",false,401)]
    static void OpenEditor()
    {
        if (m_editor_ex == null)
        {
            m_editor_ex = EditorWindow.GetWindow("EffectEditorEx", true);
            m_editor_ex.autoRepaintOnSceneChange = true;
        }
        m_editor_ex.Show(true);
    }


    private float m_start_delay = 0f;

    private void OnGUI()
    {
        GUILayout.Label("Start Delay:");
        m_start_delay = EditorGUILayout.FloatField(m_start_delay);
        if (GUILayout.Button("+"))
        {
            var items = Selection.GetFiltered(SelectionMode.ExcludePrefab);
            foreach (var item in items)
            {
                var maindata = item.main;
                maindata.startDelay = new ParticleSystem.MinMaxCurve(maindata.startDelay.constant + m_start_delay);
            }
        }
        if (GUILayout.Button("x"))
        {
            var items = Selection.GetFiltered(SelectionMode.ExcludePrefab);
            foreach (var item in items)
            {
                var maindata = item.main;
                maindata.startDelay = new ParticleSystem.MinMaxCurve(maindata.startDelay.constant * m_start_delay);
            }
        }
        if (GUILayout.Button("="))
        {
            var items = Selection.GetFiltered(SelectionMode.ExcludePrefab);
            foreach (var item in items)
            {
                var maindata = item.main;
                maindata.startDelay = new ParticleSystem.MinMaxCurve(m_start_delay);
            }
        }
    }
}

这个过程中,坑的一点是ParticleSystem.main是只读的struct,我找了半天没找到赋值的方法.结果自己测试了下,发现直接修改这个ParticleSystem.main得到的MainModule中对应的值就可以了(一脸懵逼).