Unity3D在Preview中打印日志的方法

using UnityEngine;
using UnityEditor;

[CustomEditor(typeof(Object), true)]
public class PreviewGUIEditor : Editor {
 /** Update every 15th frame. */
 private const int updateOnFrame = 15;

 private GUIStyle _previewLabelStyle;

 private GUIStyle previewLabelStyle {
 get {
  if (_previewLabelStyle == null) {
  _previewLabelStyle = new GUIStyle("PreOverlayLabel") {
   richText = false,
   alignment = TextAnchor.UpperLeft,
   fontStyle = FontStyle.Normal
  };
  // Try to get a fixed-width font on macOS.
  var font = Font.CreateDynamicFontFromOSFont("Monaco", 12);
  // Failing that, try to get a fixed-width font on Windows.
  if (font == null)
   font = Font.CreateDynamicFontFromOSFont("Lucida Console", 12);
  // XXX What fixed-width font should I request if we're on Linux?
  if (font != null)
   _previewLabelStyle.font = font;
  // Debug.Log("Fonts: \n" + string.Join("\n", Font.GetOSInstalledFontNames()));
  }
  return _previewLabelStyle;
 }
 }

 public override bool HasPreviewGUI() {
 return Application.isPlaying;
 }

 public override bool RequiresConstantRepaint() {
 // Only repaint on the nth frame.
 return Application.isPlaying && Time.frameCount % updateOnFrame == 0;
 }

 public override void OnPreviewGUI(Rect rect, GUIStyle background) {

 string str = target.ToString();

 GUI.Label(rect, str, previewLabelStyle);
 }
}

using UnityEngine;

public class Player : MonoBehaviour
{
 public int health = 10;

 public int power = 10;
 // Use this for initialization
 void Start () {
 
 }
 
 // Update is called once per frame
 void Update ()
 {
 health += 1;
 power += 2;

 Debug.LogError("health = "+ health);
 Debug.LogError("power = "+ power);
 
 }

 public override string ToString()
 {
 return "health = " + health+"\n"+
   "power = " + power;
 }
}