c# WPF 不同窗口，调用一个文件类，定义方法通过Http从远程服务下载某个文件夹的所有图片或某个图片

在C#的WPF应用程序中，如果你想要在一个主窗口或其他窗口中调用一个专门负责处理HTTP请求的文件类，以便从远程服务器下载文件夹中的所有图片或特定图片，可以按照以下步骤操作：

1. **创建一个文件类**（例如`FileDownloader.cs`）:

using System;
using System.IO;
using System.Net.Http;

public class FileDownloader
{
    private readonly HttpClient _httpClient;

    public FileDownloader()
    {
        _httpClient = new HttpClient();
    }

    // 定义公共方法下载目录下的所有图片
    public async Task DownloadDirectoryAsync(string url)
    {
        var response = await _httpClient.GetAsync(url);
        if (response.IsSuccessStatusCode)
        {
            string imageUrlPattern = $"{url}/*.{jpg|png|gif}"; // 根据需要调整图片格式
            await DownloadFilesFromPattern(imageUrlPattern);
        }
        else
        {
            Console.WriteLine($"Failed to fetch directory. Status code: {response.StatusCode}");
        }
    }

    // 私有方法下载符合模式的图片
    private async Task DownloadFilesFromPattern(string pattern)
    {
        try
        {
            var response = await _httpClient.SendAsync(new HttpRequestMessage(HttpMethod.Get, pattern));
            using var content = await response.Content.ReadAsStreamAsync();
            if (content != null)
            {
                await SaveToDiskAsync(content);
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error downloading files: {ex.Message}");
        }
    }

    // 将响应内容保存到本地磁盘的方法
    private async Task SaveToDiskAsync(Stream inputStream)
    {
        string filePath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Downloads"); // 获取应用安装路径的Download子目录

        if (!Directory.Exists(filePath))
        {
            Directory.CreateDirectory(filePath);
        }

        string fileNameWithoutExtension = Path.GetFileNameWithoutExtension(inputStream.Name);
        string fullFileName = Path.Combine(filePath, fileNameWithoutExtension);

        using (var outputStream = File.Create(fullFileName))
        {
            await inputStream.CopyToAsync(outputStream);
        }
    }
}

2. **在需要调用该类的窗口上使用它**:

在你的WPF窗口类（如`MainWindow.xaml.cs`）中，注入`FileDownloader`实例并调用其方法：

public partial class MainWindow : Window
{
    private readonly FileDownloader _fileDownloader;

    public MainWindow()
    {
        InitializeComponent();

        _fileDownloader = new FileDownloader(); // 创建下载器实例

        // 想要在点击按钮或满足某个条件时开始下载，添加事件处理
        Button downloadButton = FindResource("YourDownloadButton") as Button; // 替换"YourDownloadButton"为你的按钮名
        downloadButton.Click += DownloadButton_Click;
    }

    private async void DownloadButton_Click(object sender, RoutedEventArgs e)
    {
        string remoteFolderPath = "http://yourremote/folder/"; // 远程文件夹URL
        await _fileDownloader.DownloadDirectoryAsync(remoteFolderPath);
    }
}