.NET Core 7 API中JWT在jwt.io显示‘Invalid Signature’求助

我在.NET Core 7 API解决方案中实现JWT令牌的生成与验证功能，但在jwt.io调试工具中查看令牌详情时，出现了Invalid Signature（无效签名）错误。

已尝试的解决方案：

• 使用Base64编码的密钥作为密钥
• 勾选/取消勾选‘secret base64 encoded’复选框
• 在Appsettings.json文件中将JWT密钥转换为Base64格式

恳请各位帮忙指出问题所在，提前致谢 :)

代码片段 #

创建JWT令牌方法 #

private string CreateJWTToken(User user)
{
    List<Claim> claims = new List<Claim>{
        new Claim(ClaimTypes.Name, user.UserName)
        // new Claim(ClaimTypes.Role,"AssignSomeRole"),
    };

    var SymmetricKey = new SymmetricSecurityKey(
        Encoding.UTF8.GetBytes(_configuration.GetSection("JWT:secret").Value!));

    var SigningCredentials = new SigningCredentials(SymmetricKey, SecurityAlgorithms.HmacSha256Signature);

    var JwtTokenForUser = new JwtSecurityToken(
        issuer: "http://localhost:5255",
        audience: "",
        claims: claims,
        null,
        expires: DateTime.Now.AddDays(1),
        signingCredentials: SigningCredentials
    );

    var jwt = new JwtSecurityTokenHandler().WriteToken(JwtTokenForUser);

    return jwt;
}

Program.cs中的配置 #

builder.Services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme).AddJwtBearer(options =>
{
    options.TokenValidationParameters = new TokenValidationParameters
    {
        ValidateIssuerSigningKey = true,
        IssuerSigningKey = new SymmetricSecurityKey(
            Encoding.UTF8.GetBytes(
                builder.Configuration.GetSection("JWT:secret").Value!))
    };
});

AppSettings.json配置 #

"JWT": {
    "secret": "trytrytrytrytrytrytrytrytrytrytrytrytrytrytrytry",
    "issuer": "http://localhost:5255",
    "audience": "http://localhost:5255"
  }

内容的提问来源于stack exchange，提问作者Catalyst