使用InstaSharper上传图片报错：解析值时遇意外字符

问题分析 #

你遇到的Unexpected character encountered while parsing value: <错误，本质是上传请求返回了404的HTML页面（而非预期的JSON），且HTML里标记了not-logged-in——这说明上传请求时没有携带有效的登录会话，虽然LoginAsync返回成功，但实际会话可能未正确初始化或被后续请求丢失。

解决方案 #

1. 先验证登录会话有效性 #

登录后主动获取当前用户信息，确认会话真实有效：

if (loginResult.Succeeded)
{
    Console.WriteLine("Logged in successfully.");
    // 新增：验证会话有效性
    var userInfo = await _instaApi.GetCurrentUserAsync();
    if (!userInfo.Succeeded)
    {
        Console.WriteLine($"会话无效：{userInfo.Info.Message}");
        return;
    }
    Console.WriteLine($"当前登录用户：{userInfo.Value.Username}");
    
    await InsertImage(@"C:\Insta\testImage.png");
}

2. 修正图片路径传递方式 #

你当前通过Uri.LocalPath转换路径的方式可能导致格式异常，直接使用完整文件路径即可：

public static async Task InsertImage(string _path)
{
    var fullPath = Path.GetFullPath(_path);
    Console.WriteLine(fullPath);   
    var mediaImage = new InstaImage
    {
        URI = fullPath, // 直接用完整路径，无需Uri转换
        Width = 1080,
        Height = 1080
    };

    Console.WriteLine("Media Made");
    var result = await _instaApi.UploadPhotoAsync(mediaImage, "Caption");

    if (result.Succeeded) 
        Console.WriteLine($"Media created: {result.Value.Pk}, {result.Value.Caption}");
    else 
        Console.WriteLine($"Unable to upload photo: {result.Info.Message}");
    Console.WriteLine("End of Function");
}

3. 改用文件流上传（更可靠） #

如果路径方式仍有问题，直接传入文件流避免路径解析错误：

public static async Task InsertImage(string _path)
{
    using var imageStream = new FileStream(_path, FileMode.Open, FileAccess.Read);
    var mediaImage = new InstaImage
    {
        InputStream = imageStream,
        Width = 1080,
        Height = 1080
    };

    var result = await _instaApi.UploadPhotoAsync(mediaImage, "Caption");
    // 后续输出逻辑不变
}

4. 升级InstaSharper到最新版本 #

Instagram的API端点经常更新，旧版本的InstaSharper可能指向已废弃的上传地址，导致404。请确保使用最新版本的NuGet包。

完整修改后的代码 #

private static IInstaApi _instaApi;
private static async Task Main(string[] args)
{
    var userCredentials = new UserSessionData
    {
        UserName = "MyInstagramUsername",
        Password = "MyInstagramPassword"
    };

    _instaApi = InstaApiBuilder.CreateBuilder()
        .SetUser(userCredentials)
        .UseLogger(new DebugLogger(LogLevel.All))
        .Build();

    var loginResult = await _instaApi.LoginAsync();

    if (loginResult.Succeeded)
    {
        Console.WriteLine("Logged in successfully.");
        // 验证会话有效性
        var userInfo = await _instaApi.GetCurrentUserAsync();
        if (!userInfo.Succeeded)
        {
            Console.WriteLine($"会话验证失败：{userInfo.Info.Message}");
            return;
        }
        Console.WriteLine($"当前登录用户：{userInfo.Value.Username}");
        
        await InsertImage(@"C:\Insta\testImage.png");
    }
    else
    {
        Console.WriteLine($"Failed to log in: {loginResult.Info.Message}");
    }
}

public static async Task InsertImage(string _path)
{
    var fullPath = Path.GetFullPath(_path);
    Console.WriteLine(fullPath);   
    var mediaImage = new InstaImage
    {
        URI = fullPath,
        Width = 1080,
        Height = 1080
    };

    Console.WriteLine("Media Made");
    var result = await _instaApi.UploadPhotoAsync(mediaImage, "Caption");

    if (result.Succeeded) 
        Console.WriteLine($"Media created: {result.Value.Pk}, {result.Value.Caption}");
    else 
        Console.WriteLine($"Unable to upload photo: {result.Info.Message}");
    Console.WriteLine("End of Function");
}

内容的提问来源于stack exchange，提问作者Chasper