一篇文章搞懂unity编辑器中Event的rawType, type和GetTypeForControl

简介

Event.rawType就是初始的type，可以通过Event.Use()将rawType修改为EventType.Used。
Event.type是经过GUIClip过滤的rawType，如果事件触发时，鼠标位置位于当前GUIClip中，返回rawType，如果鼠标不在当前GUIClip中，则设置为EventType.Ignore
Event.GetTypeForControl 相对于Event.type在GUIClip过滤的基础上，增加了hotControl的判断，如果是hotControl，也直接返回rawType。

验证代码

鼠标点击浅色区域，此时鼠标位置位于GUIClip区域之外，GUICLip内的代码调用rawType会是MouseDown，type会是Ignore，由于设置了hotControl，GetTypeForControl会是MouseDown。
在我们重置hotControl为0时，GetTypeForControl的值也变成Ignore.

鼠标点击深色区域，此时鼠标位置位于GUIClip之内，此时 rawType， type 以及 GetTypeForControl 的结果都是MouseDown

public class EventDemoEditorWindow : EditorWindow
{
    [MenuItem("Demos/EventDemoEditorWindow")]
    static void ShowWindow()
    {
        var window = GetWindow<EventDemoEditorWindow>();
        window.titleContent = new GUIContent("EventDemoEditorWindow");
        window.Show();
    }


    private Event eventCache;

    private int buttonControlId;


    private void OnEnable()
    {
    }

    private void OnGUI()
    {
        //Event.GetTypeForControl
        eventCache = Event.current;

        if (MGUILayout.Button($"按钮1"))
        {
            Debug.Log("点击 按钮1");
        }
        var buttonRect = GUILayoutUtility.GetLastRect();

        buttonControlId = GetLastControlId();
        GUIUtility.hotControl = buttonControlId;
        //GUIUtility.hotControl = 0;

        //鼠标需要点击 ClipRect 的上方区域
        var clipRect = Rect.MinMaxRect(0, buttonRect.yMax+100, position.width, position.height);

        //if(eventCache.type == EventType.Repaint)
            GUI.Box(clipRect, string.Empty);

        //buttonControlId = GetLastControlId();
        //GUIUtility.hotControl = buttonControlId;

        GUI.BeginClip(clipRect, default(Vector2), default(Vector2), false);
        {

            if (eventCache.rawType == EventType.MouseDown)
            {

                EventType type;

                type = eventCache.rawType;
                Debug.Log($"rawType = {type}");

                type = eventCache.GetTypeForControl(buttonControlId);
                Debug.Log($"GetTypeForControl={type}");

                type = eventCache.type;
                Debug.Log($"type={type}");


                GUIUtility.hotControl = 0;
                Debug.Log("----------------  Set HotControl=0   ----------------- ");

                type = eventCache.rawType;
                Debug.Log($"rawType = {type}");

                type = eventCache.GetTypeForControl(buttonControlId);
                Debug.Log($"GetTypeForControl={type}");

                type = eventCache.type;
                Debug.Log($"type={type}");


                eventCache.Use();
                Debug.Log("------------------  Event.Use()   ------------------- ");

                type = eventCache.rawType;
                Debug.Log($"rawType = {type}");

                type = eventCache.type;
                Debug.Log($"type={type}");

            }

        }
        GUI.EndClip();

        

        GUIUtility.hotControl = 0;
    }

    private int GetLastControlId()
    {
        var type = typeof(EditorGUIUtility);
        var field = type.GetField("s_LastControlID", BindingFlags.Static | BindingFlags.NonPublic);
        var lastControlID = (int)field.GetValue(null);
        return lastControlID;
    }


}