unity打开windows系统外部文件夹，并选择文件内容

1、首先需要从unity打开外部文件夹并选择文件的功能，具体操作如下：

     首先创建一个单独的类，用来储存打开的系统窗口的设置，下面的变量没有特殊要求不需要做任何改动：

using UnityEngine;
using System.Collections;
using System;
using System.Runtime.InteropServices;
 
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
public class OpenFileName
{
    public int structSize = 0;
    public IntPtr dlgOwner =IntPtr.Zero;
    public IntPtr instance = IntPtr.Zero;
    public String filter = null;
    public String customFilter = null;
    public int maxCustFilter = 0;
    public int filterIndex = 0;
    public String file = null;
    public int maxFile = 0;
    public String fileTitle = null;
    public int maxFileTitle = 0;
    public String initialDir = null;
    public String title = null;