在Web Api使用Session
起因
在公司项目没使用过Web API,一直都是在使用WCF,今天建了一个Web API(Asp.Net Core)项目,使用到Session了,发现是无法使用的.是因为从Asp.Net到Asp.Net Core时,抛弃了全家桶,改为按需使用(当你需要使用的时候,再去配置).建一个空Web API项目
[HttpGet]
public WeatherForecast Get()
{
byte[] val;
HttpContext.Session.TryGetValue("key", out val); //根据key从Session获取数据
return new WeatherForecast();
}运行之后,发现报错了,如下图.
突然想起Web Api默认应该开启Session功能.在Startup.cs文件开启Session,修改Startup.cs文件.
public class Startup
{
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
services.AddControllers();
#region 开启Session
services.AddDistributedMemoryCache();
services.AddSession(x =>
{
x.IdleTimeout = TimeSpan.FromHours(1); //设置过期时间为一个小时
});
#endregion
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseRouting();
app.UseSession(); //使用Session
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
}
}给Session增加扩展方法
因为.Net Core Session默认的方法使用不是很方便,所以增加几个扩展方法,让我们使用的时候能方便一些.
namespace Microsoft.AspNetCore.Http
{
//这里使用.Net Core自带的序列化json组件,主要是方便
//正式项目中,还是使用比较均衡Json.Net组件
using System.Text.Json;
public static class SessionExtension
{
/// <summary>
/// 将泛型数据放入Session中
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="session"></param>
/// <param name="key"></param>
/// <param name="value"></param>
public static void Set<T>(this ISession session, string key, T value)
{
session.SetString(key, JsonSerializer.Serialize(value));
}
/// <summary>
/// 从Session获取泛型数据
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="session"></param>
/// <param name="key"></param>
/// <returns></returns>
public static T Get<T>(this ISession session, string key)
{
var value = session.GetString(key);
return value == null ? default(T) : JsonSerializer.Deserialize<T>(value);
}
/// <summary>
/// 从Session获取数据,返回是否成功
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="session"></param>
/// <param name="key"></param>
/// <param name="val"></param>
/// <returns></returns>
public static bool TryGetValue<T>(this ISession session, string key, out T val)
{
var value = session.GetString(key);
if (value == null)
{
val = default(T);
return false;
}
else
{
val = JsonSerializer.Deserialize<T>(value);
return true;
}
}
}
}使用:
[HttpGet]
public WeatherForecast Get()
{
WeatherForecast weather;
HttpContext.Session.Set("test", new WeatherForecast() { Summary = "11", Date = DateTime.Now, TemperatureC = 111 });
if (HttpContext.Session.TryGetValue("test", out weather))
{
return weather;
}
else
{
return new WeatherForecast();
}
}
秋风
2019-12-20