今天無意間發(fā)現(xiàn)了一篇好文章蹭秋，也讓我解決了一個很久都沒解決的難題蹋凝。問題是這樣的脐瑰，假如我想去拓展Unity自帶的inspector但是并不想影響原有布局飒货。 比如下面這段代碼：
[CustomEditor(typeof(RectTransform))]
public class MyTest : Editor
{
public override void OnInspectorGUI ()
{
base.OnInspectorGUI ();
if(GUILayout.Button("Adding this button"))
{
Debug.Log("Adding this button");
}
}
}
我的本意是想在Rect Transform面板的下面去添加一個按鈕魄衅，可是我一旦調(diào)用base.OnInspectorGUI()方法以后，原有的布局都就變了塘辅。
為什么會影響到原有布局呢晃虫？原因是這樣的上面的代碼是繼承Editor的，那么base.OnInspectorGUI()實(shí)際上去掉用了Editor類里的OnInspectorGUI()方法扣墩，可是RectTransfm的OnInspectorGUI()方法是在RectTransformEditor這個類寫的哲银。
但是問題就來了，RectTransformEditor這個類不是一個對外公開的類呻惕。所以不能繼承它荆责，那也就無法調(diào)用它的OnInspectorGUI()方法了，所以就有了上述問題亚脆。
這里有一個巧妙的反射方法做院，完美的解決這個問題。https://gist.github.com/liortal53/352fda2d01d339306e03
[CustomEditor(typeof(RectTransform))]
public class MyTest : DecoratorEditor
{
public MyTest(): base("RectTransformEditor"){}
public override void OnInspectorGUI ()
{
base.OnInspectorGUI ();
if(GUILayout.Button("Adding this button"))
{
Debug.Log("Adding this button");
}
}
}
理論上unity提供的每一個腳本都有一個 XXXEditor 類 濒持， 用來繪制它的面板键耕。（本文用到的就是 RectTransformEditor）如果你不確定可以去我反編譯的代碼里面去找。https://bitbucket.org/xuanyusong/unity-decompiled
如下圖所示柑营，現(xiàn)在既保留了原有的布局屈雄，也可以方便的拓展了。官套。
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using UnityEditor;
using UnityEngine;
/// <summary>
/// A base class for creating editors that decorate Unity's built-in editor types.
/// </summary>
public abstract class DecoratorEditor : Editor
{
// empty array for invoking methods using reflection
private static readonly object[] EMPTY_ARRAY = new object[0];
#region Editor Fields
/// <summary>
/// Type object for the internally used (decorated) editor.
/// </summary>
private System.Type decoratedEditorType;
/// <summary>
/// Type object for the object that is edited by this editor.
/// </summary>
private System.Type editedObjectType;
private Editor editorInstance;
#endregion
private static Dictionary<string, MethodInfo> decoratedMethods = new Dictionary<string, MethodInfo>();
private static Assembly editorAssembly = Assembly.GetAssembly(typeof(Editor));
protected Editor EditorInstance
{
get
{
if (editorInstance == null && targets != null && targets.Length > 0)
{
editorInstance = Editor.CreateEditor(targets, decoratedEditorType);
}
if (editorInstance == null)
{
Debug.LogError("Could not create editor !");
}
return editorInstance;
}
}
public DecoratorEditor (string editorTypeName)
{
this.decoratedEditorType = editorAssembly.GetTypes().Where(t => t.Name == editorTypeName).FirstOrDefault();
Init ();
// Check CustomEditor types.
var originalEditedType = GetCustomEditorType(decoratedEditorType);
if (originalEditedType != editedObjectType)
{
throw new System.ArgumentException(
string.Format("Type {0} does not match the editor {1} type {2}",
editedObjectType, editorTypeName, originalEditedType));
}
}
private System.Type GetCustomEditorType(System.Type type)
{
var flags = BindingFlags.NonPublic | BindingFlags.Instance;
var attributes = type.GetCustomAttributes(typeof(CustomEditor), true) as CustomEditor[];
var field = attributes.Select(editor => editor.GetType().GetField("m_InspectedType", flags)).First();
return field.GetValue(attributes[0]) as System.Type;
}
private void Init()
{
var flags = BindingFlags.NonPublic | BindingFlags.Instance;
var attributes = this.GetType().GetCustomAttributes(typeof(CustomEditor), true) as CustomEditor[];
var field = attributes.Select(editor => editor.GetType().GetField("m_InspectedType", flags)).First();
editedObjectType = field.GetValue(attributes[0]) as System.Type;
}
void OnDisable()
{
if (editorInstance != null)
{
DestroyImmediate(editorInstance);
}
}
/// <summary>
/// Delegates a method call with the given name to the decorated editor instance.
/// </summary>
protected void CallInspectorMethod(string methodName)
{
MethodInfo method = null;
// Add MethodInfo to cache
if (!decoratedMethods.ContainsKey(methodName))
{
var flags = BindingFlags.Instance | BindingFlags.Static | BindingFlags.NonPublic | BindingFlags.Public;
method = decoratedEditorType.GetMethod(methodName, flags);
if (method != null)
{
decoratedMethods[methodName] = method;
}
else
{
Debug.LogError(string.Format("Could not find method {0}", method));
}
}
else
{
method = decoratedMethods[methodName];
}
if (method != null)
{
method.Invoke(EditorInstance, EMPTY_ARRAY);
}
}
public void OnSceneGUI()
{
CallInspectorMethod("OnSceneGUI");
}
protected override void OnHeaderGUI ()
{
CallInspectorMethod("OnHeaderGUI");
}
public override void OnInspectorGUI ()
{
EditorInstance.OnInspectorGUI();
}
public override void DrawPreview (Rect previewArea)
{
EditorInstance.DrawPreview (previewArea);
}
public override string GetInfoString ()
{
return EditorInstance.GetInfoString ();
}
public override GUIContent GetPreviewTitle ()
{
return EditorInstance.GetPreviewTitle();
}
public override bool HasPreviewGUI ()
{
return EditorInstance.HasPreviewGUI ();
}
public override void OnInteractivePreviewGUI (Rect r, GUIStyle background)
{
EditorInstance.OnInteractivePreviewGUI (r, background);
}
public override void OnPreviewGUI (Rect r, GUIStyle background)
{
EditorInstance.OnPreviewGUI (r, background);
}
public override void OnPreviewSettings ()
{
EditorInstance.OnPreviewSettings ();
}
public override void ReloadPreviewInstances ()
{
EditorInstance.ReloadPreviewInstances ();
}
public override Texture2D RenderStaticPreview (string assetPath, Object[] subAssets, int width, int height)
{
return EditorInstance.RenderStaticPreview (assetPath, subAssets, width, height);
}
public override bool RequiresConstantRepaint ()
{
return EditorInstance.RequiresConstantRepaint ();
}
public override bool UseDefaultMargins ()
{
return EditorInstance.UseDefaultMargins ();
}
}
本文轉(zhuǎn)載自：http://www.xuanyusong.com/archives/3931
