1. 确认JWT Token是否正确生成并在HTTP请求的头部中正确传递。

2. 检查登录控制器中的代码是否正确处理了用户认证。以下是示例代码：

[HttpPost]
[Route("login")]
public async Task Login([FromBody] LoginViewModel model)
{
    if (!ModelState.IsValid)
    {
        return BadRequest();
    }

    var user = await _userManager.FindByEmailAsync(model.Email);
    if (user == null)
    {
        return BadRequest();
    }

    if (!await _userManager.CheckPasswordAsync(user, model.Password))
    {
        return BadRequest();
    }

    var tokenString = GenerateJWTToken(user);

    return Ok(new { token = tokenString });
}

private string GenerateJWTToken(ApplicationUser user)
{
    var claims = new List
    {
        new Claim(JwtRegisteredClaimNames.Sub, user.UserName),
        new Claim(JwtRegisteredClaimNames.Email, user.Email),
        new Claim(JwtRegisteredClaimNames.Jti, Guid.NewGuid().ToString()),
    };

    var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(_configuration["Jwt:Key"]));
    var creds = new SigningCredentials(key, SecurityAlgorithms.HmacSha256);

    var token = new JwtSecurityToken(
        _configuration["Jwt:Issuer"],
        _configuration["Jwt:Issuer"],
        claims,
        expires: DateTime.Now.AddMinutes(30),
        signingCredentials: creds);

    return new JwtSecurityTokenHandler().WriteToken(token);
}

3. 检查Authorization Middleware是否被正确添加。以下是示例代码：

public void ConfigureServices(IServiceCollection services)
{
    services.AddAuthentication(options =>
    {
        options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
        options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
    })
    .AddJwtBearer(options =>
    {
        options.RequireHttpsMetadata = false;
        options.SaveToken = true;
        options.TokenValidationParameters = new TokenValidationParameters
        {
            ValidateIssuerSigningKey = true,
            IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(Configuration["Jwt:Key"])),
            ValidateIssuer = true,
            ValidIssuer = Configuration["Jwt:Issuer"],
            ValidateAud