代码在切换分支后，Unity工程下Library文件夹(如果没有加入到版本控制中)可能会被污染，导致各种Unity的dll文件找不到，例如：
"Asset 'C:/Program Files (x86)/Unity/Editor/Data/UnityExtensions/Unity/GUISystem/4.6.0/UnityEngine.UI.dll'Unity的dll文件不能单独reimport，只能remiport all，虽然能解决问题，但是太慢太慢了，尤其是Android平台Load贴图，非常浪费时间。
一番google之后，在Unity的坛子里，网友’j-robichaud’贡献了脚本，解决了问题，如救世主一般，感动。
using UnityEngine;
using System.Collections.Generic;
using UnityEditor;
using System.Text.RegularExpressions;
using System.IO;
using System.Text;
public class ReimportUnityEngineUI
{
[MenuItem( "Assets/Reimport UI Assemblies", false, 100 )]
public static void ReimportUI()
{
#if UNITY_4_6
var path = EditorApplication.applicationContentsPath + "/UnityExtensions/Unity/GUISystem/{0}/{1}";
var version = Regex.Match( Application.unityVersion,@"^[0-9]+\.[0-9]+\.[0-9]+").Value;
#else
var path = EditorApplication.applicationContentsPath + "/UnityExtensions/Unity/GUISystem/{1}";
var version = string.Empty;
#endif
string engineDll = string.Format( path, version, "UnityEngine.UI.dll");
string editorDll = string.Format( path, version, "Editor/UnityEditor.UI.dll");
ReimportDll( engineDll );
ReimportDll( editorDll );
}
static void ReimportDll(string path )
{
if ( File.Exists( path ) )
AssetDatabase.ImportAsset( path, ImportAssetOptions.ForceUpdate| ImportAssetOptions.DontDownloadFromCacheServer );
else
Debug.LogError( string.Format( "DLL not found {0}", path ) );
}
}–EOF–