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;
    public int flags = 0;
    public short fileOffset = 0;
    public short fileExtension = 0;
    public String defExt = null;
    public IntPtr custData = IntPtr.Zero;
    public IntPtr hook = IntPtr.Zero;
    public String templateName = null;
    public IntPtr reservedPtr = IntPtr.Zero;
    public int reservedInt = 0;
    public int flagsEx = 0;
}

using System;
using UnityEngine;
using System.Collections;
using System.Runtime.InteropServices;

public class LocalDialog
{
    //链接指定系统函数       打开文件对话框
    [DllImport("Comdlg32.dll", SetLastError = true, ThrowOnUnmappableChar = true, CharSet = CharSet.Auto)]
    public static extern bool GetOpenFileName([In, Out] OpenFileName ofn);
    public static bool GetOFN([In, Out] OpenFileName ofn)
    {
        return GetOpenFileName(ofn);
    }

    //链接指定系统函数        另存为对话框
    [DllImport("Comdlg32.dll", SetLastError = true, ThrowOnUnmappableChar = true, CharSet = CharSet.Auto)]
    public static extern bool GetSaveFileName([In, Out] OpenFileName ofn);
    public static bool GetSFN([In, Out] OpenFileName ofn)
    {
        return GetSaveFileName(ofn);
    }
}

    //将文件窗口复制到某一路径下
    public void CopyFile(string path)
    {
        OpenFileName openFileName = new OpenFileName();
        openFileName.structSize = Marshal.SizeOf(openFileName);
        openFileName.filter = "TXT文件(*.txt)\0*.txt";
        openFileName.file = new string(new char[256]);
        openFileName.maxFile = openFileName.file.Length;
        openFileName.fileTitle = new string(new char[64]);
        openFileName.maxFileTitle = openFileName.fileTitle.Length;
        openFileName.initialDir = Application.streamingAssetsPath.Replace(‘/‘, ‘\\‘);//默认路径
        openFileName.title = "窗口标题";
        openFileName.flags = 0x00080000 | 0x00001000 | 0x00000800 | 0x00000008;
        if (LocalDialog.GetSaveFileName(openFileName))
        {
            Debug.Log(openFileName.file);
            Debug.Log(openFileName.fileTitle);
            File.Copy(openFileName.file,path,true);
        }
    }