【DIY】将md文件中的图片下载到本地

读取文件夹下面的*.md文件,正则匹配

![](http****)

解析到图片的网络地址，然后模拟请求将图片下载到本地替换md中的url重新写到md文件中,代码如下：

解析Md文件

private static void Main(string[] args)
{
    var path = @"C:\xguan\demo\hexo\source\_posts\";

    var dir = new DirectoryInfo(path);
    var files = dir.GetFiles($"*.md");
    foreach (var file in files)
    {
        StreamReader sr = new StreamReader(file.FullName, Encoding.UTF8);
        var source = sr.ReadToEnd();

        Regex regex = new Regex(@"!\[\]\((.*?)\)", RegexOptions.IgnoreCase);
        MatchCollection matches = regex.Matches(source);
        foreach (var matche in matches)
        {
            var url = matche.ToString().Replace("![](", "").TrimEnd(')');

            var fileName = Path.GetFileName(url);
            if (url.IndexOf("?") != -1)
            {
                fileName = Path.GetFileName(url.Substring(0, url.IndexOf("?")));
            }

            if (Path.GetExtension(fileName).Length == 0)
            {
                fileName = $"{fileName}.png";
            }
            var newImgSrc = $"./images/{fileName}";

            if (DownloadFile(url, newImgSrc))
            {
                source = source.Replace(url, newImgSrc);
                Console.WriteLine($"处理前：{url}");
                Console.WriteLine($"处理后：{newImgSrc}");
                Console.WriteLine();
            }
        }
        //copy 重新写文件
        using (FileStream fs = new FileStream($"./copy/{file.Name}", FileMode.OpenOrCreate))
        {
            byte[] data = System.Text.Encoding.UTF8.GetBytes(source);
            fs.Write(data, 0, data.Length);
        }
        System.Threading.Thread.Sleep(1000);
    }
    Console.WriteLine("处理完成");
    Console.ReadLine();
}

下载图片

private static bool DownloadFile(string url, string filename)
{
    if (!url.StartsWith("http"))
    {
        return false;
    }
    try
    {
        HttpWebRequest Myrq = (HttpWebRequest)HttpWebRequest.Create(url);
        using (HttpWebResponse myrp = (HttpWebResponse)Myrq.GetResponse())
        {
            using (Stream st = myrp.GetResponseStream())
            {
                Stream so = new FileStream($"{filename}", FileMode.OpenOrCreate);
                byte[] by = new byte[1024];
                int osize = st.Read(by, 0, (int)by.Length);
                while (osize > 0)
                {
                    so.Write(by, 0, osize);
                    osize = st.Read(by, 0, (int)by.Length);
                }
                so.Close();
                Myrq.Abort();
            }
        };
        return true;
    }
    catch (System.Exception e)
    {
        Console.WriteLine(e.Message);
        return false;
    }
}