int Run(string[] args) {

        _server = new HttpListener();
        _server.Prefixes.Add("http://*:9669/");
        _server.Start();

        Console.WriteLine("Server bound to: {0}",_server.Prefixes.First());

        _server.BeginGetContext(HandleContext,null);
    }

如果我绑定到系统端口,我可以理解需要以管理员身份运行,但我不明白为什么我对9669的绑定应该需要特殊权限.

有任何想法吗？

我有一个答案.

netsh http add urlacl url=http://*:9669/ user=fak listen=yes

疯.这是我修改过的功能：

int Run(string[] args) {

        var prefix = "http://*:9669/";
        var username = Environment.GetEnvironmentvariable("USERNAME");
        var userdomain = Environment.GetEnvironmentvariable("USERDOMAIN");

        _server = new HttpListener();
        _server.Prefixes.Add(prefix);

        try {
            _server.Start();
        }
        catch (HttpListenerException ex) {
            if (ex.ErrorCode == 5) {
                Console.WriteLine("You need to run the following command:");
                Console.WriteLine("  netsh http add urlacl url={0} user={1}\\{2} listen=yes",prefix,userdomain,username);
                return -1;
            }
            else {
                throw;
            }
        }


        Console.WriteLine("Server bound to: {0}",null);
    }

Response.Headers["X-XRDS-Location"] = url

例外消息：

This operation requires IIS integrated pipeline mode.

任何帮助,将不胜感激.

type
  TForm1 = class(TForm)
    Image1: timage;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

procedure TForm1.Button1Click(Sender: TObject);
var
  imagestream: TStream;
begin
  imagestream := TStream.Create;
  Image1.Picture.Bitmap.SavetoStream(imagestream);
  ...
end;

我需要提取TBitmap的流以供以后处理……我做错了什么？

TStream is the base class type for stream objects that can read from or write to varIoUs kinds of storage media,such as disk files,dynamic memory,and so on.

Use specialized stream objects to read from,write to,or copy information stored in a particular medium.

您可能希望使用TMemoryStream或TFileStream,顾名思义,它将流内容存储在内存或系统文件中.

procedure TForm1.Button1Click(Sender: TObject);
var
  imagestream: TMemoryStream;
begin
  imagestream := TMemoryStream.Create;
  try
    Image1.Picture.Bitmap.SavetoStream(imagestream);
    ...
  finally
    imagestream.Free;
  end;
end;

class polymorphisomTest {

    class Base {
        public void doTest(double d) {
            System.out.println("From Base");
        }
    }

    class DerivedBase extends Base {

        public void doTest(int d) {
            System.out.println("From Derived Base");
        }
    }

    public void use(Base  base) {
        base.doTest(3);
    }
    public void run() {
        use(new Base());
        use(new DerivedBase ());
    }
    public static void main(String []cmd) {
        new polymorphisomTest ().run();
    }
}

这里是来自父类的doTest(double d)和来自子类的doTest(int d),但是当我调用base.doTest(3)时,它总是调用父类方法,即使我的对象引用是不同的.这背后的原因是什么？

class Base {
    public void doTest(double d) {
        System.out.println("From Base");
    }
}

class DerivedBase extends Base {
    public void doSomethingElse(int d) {
        System.out.println("From Derived Base");
    }
}

更改参数的类型会更改方法签名,并使其成为新方法,而不是覆盖父类的方法.

当你调用base.doTest(3)时,编译器将调用doTest(double),因为这是Base类与参数匹配的唯一方法.因为该方法没有被任何东西覆盖,所以会调用Base.doTest.