unity调用windows窗口选择文件并保存

1、先定义OpenFileName数据接收类

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;
}

2、再定义系统函数调用类 

public class LocalDialog
{
    //链接指定系统函数       打开文件对话框
    [DllImport("Comdlg32.dll", SetLastError = true, ThrowOnUnmapp