无法访问iPad上的文档文件夹来编写和创建文件

Question

我正在使用Unity 5.6和Xcode 8.3.3，编译服务器可以成功导出'.ipa'文件，但应用程序无法访问文档文件夹。

    Sep 25 11:09:56 padding-0 kernel[0] <Notice>: Sandbox: shiphunter(583) deny(1) file-write-create /Documents
    Sep 25 11:09:56 padding-0 kernel[0] <Notice>: Sandbox: shiphunter(583) deny(1) file-write-create /Documents
    Sep 25 11:09:56 padding-0 kernel[0] <Notice>: Sandbox: shiphunter(583) deny(1) file-write-create /Documents
    Sep 25 11:09:56 padding-0 kernel[0] <Notice>: Sandbox: shiphunter(583) deny(1) file-write-create /Documents

我用来复制和写作的路径：

public static string ConfigPath
{
    get
    {
        // the raw file path    
        return Path.Combine(Application.streamingAssetsPath, "Config");
    }
}

public static string RESOURCE_FILE_PATH
{
    get { return Path.Combine(Application.persistentDataPath, "res"); }
}

代码访问并在文档文件夹中创建新文件如下，可能步骤2或3导致此问题，我猜。

// 1. copy the raw data into bytes array
var bytes = new byte[0];
var dbpath = Path.Combine(Util.ConfigPath, "warship.sqlite3");
try
{
    using (var fs = new FileStream(dbpath, FileMode.Open, FileAccess.Read, FileShare.Read))
    {
        bytes = new byte[fs.Length];
        fs.Read(bytes, 0, (int) fs.Length);
    }
}
catch (Exception e)
{
    Debug.LogError(e);
}

// 2. create the res folder under documents if not exists
if (!Directory.Exists(RESOURCE_FILE_PATH))
{
    Directory.CreateDirectory(RESOURCE_FILE_PATH);
}

// 3. write the bytes data into documents res foloder
var filename = Path.Combine(RESOURCE_FILE_PATH, "warship.sqlite3"); 
try
{
    var fs = new FileStream(filename, FileMode.Create, FileAccess.Write);

    if (fs == null)
    {
        Debug.LogError("file stream is null:" + filename);
    }
    else
    {
        fs.Write(bytes, 0, bytes.Length);
        fs.Close();
    }
}
catch (Exception e)
{
    Debug.LogError(e + ":" + e.StackTrace);
}