从Reddit下载图片

Question

using System;
using System.Linq;
using RedditSharp;
using System.Net;
using RedditSharp.Things;

namespace reSharp
{
    class Program
    {
        public static void Main()
        {
            string sub = "/r/";
            string saveDir = @"SAVE_DIRECTORY";
            Console.WriteLine("Subreddit:");
            sub += Console.ReadLine();

            Console.WriteLine("Amount:");
            int amount = Convert.ToInt32(Console.ReadLine());
            amount += 1;

            Console.WriteLine("Time Period");
            string timePer = Console.ReadLine();

            Reddit reddit = new Reddit();
            var subreddit = reddit.GetSubreddit(sub);
            if (timePer == "all")
            {
                foreach (var post in subreddit.GetTop(FromTime.All).Take(amount))
                {
                    if (post.IsStickied || post.IsSelfPost || Convert.ToString(post.Url).Contains("reddituploads")) continue;
                    string postURL = Convert.ToString(post.Url);
                    DownloadImages(postURL, saveDir);

                }
            }
            else
            {
                if (timePer == "hot")
                {
                    foreach (var post in subreddit.Hot.Take(amount))
                    {
                        if (post.IsStickied || post.IsSelfPost || Convert.ToString(post.Url).Contains("reddituploads")) continue;
                        string postURL = Convert.ToString(post.Url);
                        DownloadImages(postURL, saveDir);

                    }
                }
            }

        }

        public static void DownloadImages(string imageURL, string userDir)
        {

            if (imageURL.Contains("gfycat.com"))
            {
                imageURL = imageURL.Replace("gfycat.com", "zippy.gfycat.com") + ".mp4";
            }

            if (imageURL.Contains(".gifv"))
            {
                imageURL = imageURL.Replace(".gifv", ".mp4");
            }

            Console.WriteLine("Downloading {0}", imageURL);
            string[] splitURL = imageURL.Split('/');
            int index = splitURL.Length - 1;
            string fileName = splitURL[index];
            WebClient client = new WebClient();
            try
            {
                client.DownloadFile(imageURL, userDir + fileName);
            }
            catch (Exception)
            {
                Console.WriteLine("[INFO] ERROR DOWNLOADING FILE");
            }
        }
    }
}

该程序实际上只是从给定的reddit subreddit下载图片。这怎么可能是潮水？谢谢。

Answer 1

你几乎没什么能做的。从封装这些行开始

if (imageURL.Contains("gfycat.com")) { imageURL = imageURL.Replace("gfycat.com"，"zippy.gfycat.com") + ".mp4"；} if (imageURL.Contains(".gifv")) { imageURL = imageURL.Replace(".gifv"，".mp4")；}

用他们自己的方法。让我们称之为FixImageUrl (这是C# 7)

public static string FixImageUrl(string imageUrl)
{
    switch (imageUrl)
    {
        case string url when url.Contains("gfycat.com"):
            return imageUrl.Replace("gfycat.com", "zippy.gfycat.com") + ".mp4";

        case string url when url.Contains(".gifv"):
            return imageUrl.Replace(".gifv", ".mp4");

        default: return imageUrl;
    }
}

string[] splitURL = imageURL.Split('/')；int索引= splitURL.Length - 1；string fileName = splitURL索引；

然后，您可以通过使用Last扩展来简化这一点：

var fileName = imageURL.Split('/').Last();

这可能并不重要，但总是处理一次性物品是一个好习惯。这意味着WebClient需要特别的照顾。

你也想知道哪里出了问题，所以不要吞下这个例外。打印消息或记录整个异常。

在使用路径时，您应该使用Path.Combine方法来避免任何无效路径，如缺少\等的路径。

try
{
    using (var client = new WebClient())
    {
        client.DownloadFile(imageURL, Path.Combine(userDir, fileName));
    }
}
catch (Exception ex)
{
    Console.WriteLine($"[INFO] ERROR DOWNLOADING FILE: {ex}");
}