Unity打开本地文件（不使用dll的情况下）

更全的链接：Unity 选择本地目录选择文件打开指定文件夹(无需引入dll)_love and share-CSDN博客https://blog.csdn.net/qq_39342142/article/details/103781728

比较适合的内容：

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

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]

public class OpenFile
{
    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;
}

public class WindowDll
{
    [DllImport("Comdlg32.dll", SetLastError = true, ThrowOnUnmappableChar = true, CharSet = CharSet.Auto)]
    public static extern bool GetOpenFileName([In, Out] OpenFile of);

    [DllImport("Comdlg32.dll", SetLastError = true, ThrowOnUnmappableChar = true, CharSet = CharSet.Auto)]
    public static extern bool GetSaveFileName([In, Out] OpenFile ofn);
    /// 

    /// 用于获取当前Player窗口指针。
    /// 
    /// 
    [DllImport("user32.dll")]
    private static extern IntPtr GetForegroundWindow();

    /// 

    /// 打开文件
    /// 
    /// 过滤器
    /// 默认打开的路径
    /// 
    public static string OpenFile(string filter, string m_defaultPath)
    {
        OpenFile of = new OpenFile();
        of.structSize = Marshal.SizeOf(of);
        of.filter = filter;
        of.file = new string(new char[256]);
        of.maxFile = of.file.Length;
        of.fileTitle = new string(new char[64]);
        of.maxFileTitle = of.fileTitle.Length;
        of.dlgOwner = GetForegroundWindow();
        string defaultPath = m_defaultPath;
        defaultPath = defaultPath.Replace('/', '\');
        of.initialDir = defaultPath;
        of.title = "小宝贝儿，Word很大你忍一下";
        of.defExt = "DOCX";
        of.flags = 0x00080000 | 0x00001000 | 0x00000800 | 0x00000200 | 0x00000008;
        if (WindowDll.GetOpenFileName(of))
        {
            Debug.Log("Selected file with full path: {0}" + of.file);
            return of.file;
        }
        return string.Empty;
    }
}

        其中需要注意的有一个地方就是，当对话框打开之后，鼠标点击其他位置，对话框会聚焦失败，在Unity里面会导致Unity崩溃，发布出来之后主线程卡死，不切回对话框的话，会无法往下走。

        解决方案：

                （1）、把对话框一直放在最前方，也就是上面的贴的代码

                （2）、使用GetActiveWindow() ，也会解决这个问题

两个方案也是有区别的，查了一下资料        (21条消息) GetActiveWindow与GetForegroundWindow两者有何区别？_彷徨而立的博客-CSDN博客_getforegroundwindow

大概意思就是GetForegroundWindow是系统级别的最前方，而GetActiveWindow是你当前线程级别的最前方。

测试一下两者的区别：

GetForegroundWindow：

        登录QQ的情况下，因为QQ是保持在系统最前方的，用GetForegroundWindow获取最前方的窗口的时候，拿到的还是对话框窗口，只是当打开Console界面的时候，点击Console界面会导致该界面保持在最前方，然后Unity的代码产生编译，导致Unity出现BUG

Reload Assembly called from managed code directly. This will cause a crash. You should never refresh assets in synchronous mode or enter playmode synchronously from script code.

GetActiveWindow：

        与GetForegroundWindow一样的问题

发布没有测试，如果有发布测试之后有不同反应的，可以评论留言