1. 确认Bearer令牌正确。在请求头部中添加Authorization属性，其值应该是Bearer令牌。

HttpContext.Request.Headers.TryGetValue("Authorization", out var authorizationHeaderValue);

if (authorizationHeaderValue.Count > 0) { var token = authorizationHeaderValue.FirstOrDefault(); // Do something with the token }

2. 确认令牌是否有效。在创建JWT令牌时，应设置IssuerSigningKey和ValidateIssuerSigningKey等选项以验证令牌的有效性。

services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme) .AddJwtBearer(options => { options.TokenValidationParameters = new TokenValidationParameters { ValidateIssuerSigningKey = true, IssuerSigningKey = new SymmetricSecurityKey(Encoding.ASCII.GetBytes(Configuration["Jwt:SigningKey"])), ValidateIssuer = true, ValidIssuer = Configuration["Jwt:Issuer"], ValidateAudience = true, ValidAudience = Configuration["Jwt:Audience"], RequireExpirationTime = true, ValidateLifetime = true, ClockSkew = TimeSpan.Zero }; });

3. 确认API控制器上的授权特性。在API控制器上添加[Authorize]特性，以确保请求已经通过身份验证。

[Authorize] [ApiController] public class MyApiController : ControllerBase { // API actions }