在C#中處理WebDAV權限設置，可以使用System.Net.Http命名空間中的HttpClient類來發送HTTP請求

1. 首先，確保已經安裝了Microsoft.AspNet.WebApi.Client NuGet包。

2. 創建一個HttpClient實例，并設置基本URL和憑據（用戶名和密碼）：

using System;
using System.Net.Http;
using System.Net.Http.Headers;

namespace WebDavPermissionExample
{
    class Program
    {
        static void Main(string[] args)
        {
            var baseUrl = "https://your-webdav-server.com";
            var username = "your-username";
            var password = "your-password";

            using (var httpClient = new HttpClient())
            {
                httpClient.BaseAddress = new Uri(baseUrl);
                httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(Encoding.ASCII.GetBytes($"{username}:{password}")));

                // 調用其他方法來處理WebDAV權限設置
            }
        }
    }
}

3. 使用HttpClient實例發送PROPFIND請求以獲取資源的當前權限：

private static async Task<string> GetCurrentPermissionsAsync(HttpClient httpClient, string resourcePath)
{
    var request = new HttpRequestMessage(new HttpMethod("PROPFIND"), resourcePath);
    request.Headers.Add("Depth", "0");

    var response = await httpClient.SendAsync(request);
    response.EnsureSuccessStatusCode();

    var responseContent = await response.Content.ReadAsStringAsync();
    return responseContent;
}

4. 解析響應內容以獲取當前權限：

private static string ParsePermissionsFromResponse(string responseContent)
{
    // 使用XML解析器（如XmlDocument或XDocument）解析響應內容并提取權限信息
    // 這里只是一個示例，你需要根據實際的WebDAV服務器響應格式進行解析
    return "current-permissions";
}

5. 使用HttpClient實例發送PROPPATCH請求以更新資源的權限：

private static async Task SetPermissionsAsync(HttpClient httpClient, string resourcePath, string permissions)
{
    var request = new HttpRequestMessage(new HttpMethod("PROPPATCH"), resourcePath);
    request.Headers.Add("Depth", "0");

    // 構建請求正文，包含要設置的新權限
    // 這里只是一個示例，你需要根據實際的WebDAV服務器要求構建正文
    var requestBody = $"<?xml version=\"1.0\" encoding=\"utf-8\"?><D:propertyupdate xmlns:D=\"DAV:\"><D:set><D:prop><D:your-permission-element>{permissions}</D:your-permission-element></D:prop></D:set></D:propertyupdate>";
    request.Content = new StringContent(requestBody, Encoding.UTF8, "application/xml");

    var response = await httpClient.SendAsync(request);
    response.EnsureSuccessStatusCode();
}

6. 在Main方法中調用這些方法來獲取當前權限并設置新權限：

var resourcePath = "/path/to/your/resource";

// 獲取當前權限
var currentPermissions = await GetCurrentPermissionsAsync(httpClient, resourcePath);
Console.WriteLine($"Current permissions: {currentPermissions}");

// 解析當前權限
var parsedPermissions = ParsePermissionsFromResponse(currentPermissions);
Console.WriteLine($"Parsed permissions: {parsedPermissions}");

// 設置新權限
var newPermissions = "new-permissions";
await SetPermissionsAsync(httpClient, resourcePath, newPermissions);
Console.WriteLine($"New permissions set: {newPermissions}");

注意：這些示例代碼僅作為參考，你需要根據實際的WebDAV服務器實現和響應格式進行調整。在處理權限時，請確保遵循服務器的文檔和最佳實踐。