如何将CSV读取到C#类并构建PUT请求提交数据

Hey Laura, let's get your code working properly! You're almost there—we just need to add the CSV parsing logic and wire up the JSON request body. Let's break this down step by step:

1. Parsing the CSV Rows #

First, we need to split each line into id and name. A few quick considerations:

• If your CSV has a header row (like id,name), we should skip it to avoid treating column names as data.
• For simple CSVs (no commas inside the name values), a basic Split(',') works, but if names might contain commas, you’ll want a dedicated CSV library like CsvHelper for reliability (we’ll stick to vanilla .NET for this example though).

Here’s how to update your loop to handle row splitting:

try
{
    var csv = new List<Department>();
    var lines = System.IO.File.ReadAllLines(@"C:\file.csv");
    
    // Skip header row if your CSV includes one
    for (int i = 1; i < lines.Length; i++)
    {
        string line = lines[i];
        string[] parts = line.Split(',');
        
        // Guard against malformed lines
        if (parts.Length >= 2)
        {
            string id = parts[0].Trim(); // Trim extra whitespace just in case
            string name = parts[1].Trim();
            
            csv.Add(new Department { id = id, name = name });
            
            // Now we can build the URL and send the PUT request
            string url = $"https://www.test.com/department/{id}";
            
            // We'll handle the request logic next...
        }
        else
        {
            Console.WriteLine($"Skipping invalid line: {line}");
        }
    }
}
catch (Exception ex)
{
    Console.WriteLine($"Error reading CSV: {ex.Message}");
}

2. Building the JSON Body & Sending the PUT Request #

Instead of using HttpWebRequest (which is a bit outdated), let’s use HttpClient—it’s simpler, more efficient, and designed for repeated requests. We’ll also use .NET’s built-in System.Text.Json to serialize your Department object to JSON.

Here’s the full updated code with request handling:

// Reuse a single HttpClient instance (prevents socket exhaustion!)
private static readonly HttpClient _httpClient = new HttpClient();

static async Task Main(string[] args)
{
    try
    {
        var csv = new List<Department>();
        var lines = System.IO.File.ReadAllLines(@"C:\file.csv");
        
        // Set authorization header once for all requests
        _httpClient.DefaultRequestHeaders.Authorization = 
            new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", "77ba42a2d0511e109068bcb9857d035da27a4eae");
        
        // Skip header row
        for (int i = 1; i < lines.Length; i++)
        {
            string line = lines[i];
            string[] parts = line.Split(',');
            
            if (parts.Length >= 2)
            {
                string id = parts[0].Trim();
                string name = parts[1].Trim();
                var department = new Department { id = id, name = name };
                
                csv.Add(department);
                
                // Build target URL
                string url = $"https://www.test.com/department/{id}";
                
                // Serialize department to JSON request body
                string jsonBody = System.Text.Json.JsonSerializer.Serialize(department);
                var content = new StringContent(jsonBody, System.Text.Encoding.UTF8, "application/json");
                
                // Send PUT request asynchronously
                HttpResponseMessage response = await _httpClient.PutAsync(url, content);
                
                // Handle response status
                if (response.IsSuccessStatusCode)
                {
                    Console.WriteLine($"Successfully updated department {id}");
                }
                else
                {
                    string errorDetails = await response.Content.ReadAsStringAsync();
                    Console.WriteLine($"Failed to update {id}. Status: {response.StatusCode}. Error: {errorDetails}");
                }
            }
            else
            {
                Console.WriteLine($"Skipping invalid line: {line}");
            }
        }
    }
    catch (Exception ex)
    {
        Console.WriteLine($"Unexpected error: {ex.Message}");
    }
}

public class Department 
{ 
    public string id { get; set; } 
    public string name { get; set; } 
}

Quick Tips: #

• Reuse HttpClient: Creating a new instance per request can cause socket exhaustion, so a static instance is better.
• Async/Await: Using async operations keeps your code non-blocking, which is ideal for I/O tasks like HTTP requests.
• Error Handling: We added checks for malformed CSV lines and HTTP failures to help you debug issues.
• Complex CSVs: If your CSV has quoted fields or commas inside names, grab the CsvHelper NuGet package—it handles edge cases way better than a simple Split(',').

内容的提问来源于stack exchange，提问作者Laura Bejjani