使用IApplicationBuilder注册中间件
Use()：
app.Use(async (context, next) =>
{
await context.Response.WriteAsync("hello world");
await next.Invoke();
});
app.Use((requestDelegate) =>
{
return async (context) =>
{
await context.Response.WriteAsync("hello world2");
await requestDelegate(context);
};
});
UseMiddleWare()：将中间件封装，最终是使用Use注册
//自定义中间件
public class TestMiddelware
{
public RequestDelegate _next;
public TestMiddelware(RequestDelegate next)
{
this._next = next;
}
public Task Invoke(HttpContext context)
{
if (context.Request.Path.Value.Contains("1.jpg"))
{
return context.Response.SendFileAsync("1.jpg");
}
if (this._next != null)
{
return this._next(context);
}
throw new Exception("TestMiddelware error");
}
}
app.UseMiddleware<TestMiddelware>(app, Array.Empty<object>());
Run(RequestDelegate handler)：
终结点，在管道尾端增加一个中间件，之后的中间件不再执行
app.Run(async context => {
await context.Response.WriteAsync("hello world3");
});
Map()、MapWhen()管道中增加分支，条件匹配就走分支，且不切换回主分支
Map() :
app.Map(new PathString("/test"), application =>
{
application.Use(async (context, next) =>
{
await context.Response.WriteAsync("test");
await next();
});
});
MapWhen()：按条件执行，MapWhen比Map处理范围更广
app.MapWhen(context => context.Request.Path.Value.Contains("q"), application => {
application.Use(async (context, next) =>
{
await context.Response.WriteAsync("q");
await next();
});
});