System.Net.Socket.TSocket.ReceiveFrom

• Up to Parent: TSocket

Delphi

function ReceiveFrom(var Buf; Count: Integer; Flags: Integer): Integer; overload;
function ReceiveFrom(var Buf; Count: Integer; Flags: TSocketFlags = []): Integer; overload; inline;
function ReceiveFrom(Count: Integer = -1; Flags: TSocketFlags = []): TBytes; overload; inline;
function ReceiveFrom(out Bytes: TBytes; Count: Integer = -1; Flags: TSocketFlags = []): Integer; overload; inline;
function ReceiveFrom(var Bytes: array of Byte; Offset: Integer = 0; Count: Integer = -1; Flags: TSocketFlags = []): Integer; overload;
function ReceiveFrom(var Buf; Count: Integer; out Endpoint: TNetEndpoint; Flags: Integer): Integer; overload;
function ReceiveFrom(var Buf; Count: Integer; out Endpoint: TNetEndpoint; Flags: TSocketFlags = []): Integer; overload; inline;
function ReceiveFrom(out Endpoint: TNetEndpoint; Count: Integer = -1; Flags: TSocketFlags = []): TBytes; overload; inline;
function ReceiveFrom(out Bytes: TBytes; out Endpoint: TNetEndpoint; Count: Integer = -1; Flags: TSocketFlags = []): Integer; overload;
function ReceiveFrom(var Bytes: array of Byte; out Endpoint: TNetEndpoint; Offset: Integer = 0; Count: Integer = -1; Flags: TSocketFlags = []): Integer; overload;

C++

int __fastcall ReceiveFrom(void *Buf, int Count, int Flags)/* overload */;
int __fastcall ReceiveFrom(void *Buf, int Count, TSocketFlags Flags = TSocketFlags() )/* overload */;
System::DynamicArray<System::Byte> __fastcall ReceiveFrom(int Count = 0xffffffff, TSocketFlags Flags = TSocketFlags() )/* overload */;
int __fastcall ReceiveFrom(/* out */ System::DynamicArray<System::Byte> &Bytes, int Count = 0xffffffff, TSocketFlags Flags = TSocketFlags() )/* overload */;
int __fastcall ReceiveFrom(System::Byte *Bytes, const int Bytes_High, int Offset = 0x0, int Count = 0xffffffff, TSocketFlags Flags = TSocketFlags() )/* overload */;
int __fastcall ReceiveFrom(void *Buf, int Count, /* out */ TNetEndpoint &Endpoint, int Flags)/* overload */;
int __fastcall ReceiveFrom(void *Buf, int Count, /* out */ TNetEndpoint &Endpoint, TSocketFlags Flags = TSocketFlags() )/* overload */;
System::DynamicArray<System::Byte> __fastcall ReceiveFrom(/* out */ TNetEndpoint &Endpoint, int Count = 0xffffffff, TSocketFlags Flags = TSocketFlags() )/* overload */;
int __fastcall ReceiveFrom(/* out */ System::DynamicArray<System::Byte> &Bytes, /* out */ TNetEndpoint &Endpoint, int Count = 0xffffffff, TSocketFlags Flags = TSocketFlags() )/* overload */;
int __fastcall ReceiveFrom(System::Byte *Bytes, const int Bytes_High, /* out */ TNetEndpoint &Endpoint, int Offset = 0x0, int Count = 0xffffffff, TSocketFlags Flags = TSocketFlags() )/* overload */;

Properties

Type	Visibility	Source	Unit	Parent
function	public	System.Net.Socket.pas System.Net.Socket.hpp	System.Net.Socket	TSocket

Description

Receives data from a remote socket.

In order to use ReceiveFrom, the type of your socket must be either TCP or UDP.

ReceiveFrom blocks the caller until it returns the requested data.

You may pass ReceiveFrom the following parameters:

• Buf is a pointer to the buffer to receive the incoming data.
• Offset is a number of bytes to skip at the beginning of the requested data.
• Count is the length (in bytes) of the buffer pointed by Buf, which is also the maximum length of the requested data that ReceiveFrom returns.
• Flags is a set of flags that influence the behavior of ReceiveFrom. For more information, see the documentation of the recvfrom function in the MSDN.

The Endpoint output parameter indicates the source end point that sends the data.

Instead of providing a pointer to a buffer (Buf), you may either provide no such argument and let ReceiveFrom return the requested data, or provide an output parameter, Bytes, that ReceiveFrom can fill with the requested data. In both cases, the returned data never amounts to more than the specified Count of bytes.

Exceptions

A call to ReceiveFrom can raise any of the following exceptions:

Exception	Exception.Message	Scenarios
ESocketError	Network socket error: <error message> (<error code>), on API 'ioctlsocket'	The operating system reported an error while reading the length of the received data. This may happen if you provide -1 as the value of Count or if you provide the Bytes parameter in your call. For more information, see the following documentation for the operating system where your application was running: Windows: ioctlsocket function (MSDN) Mac OS X: ioctl (OS X Man Pages) iOS: ioctl (iOS Manual Pages) Android: ioctl (Linux Programmer's Manual)
	Network socket error: <error message> (<error code>), on API 'recvfrom'	The operating system reported an error while receiving data from your socket. This may happen if you provide a value other than -1 as the value of Count. For more information, see the following documentation for the operating system where your application was running: Windows: recvfrom function (MSDN) Mac OS X: recvfrom (OS X Man Pages) iOS: recvfrom (iOS Manual Pages) Android: recvfrom (Linux Programmer's Manual)

See Also

• System.Byte
• System.SysUtils.TBytes

• System.Net.Socket.TSocket.SocketType

• System.Net.Socket.TSocket.BeginReceiveFrom
• System.Net.Socket.TSocket.EndReceiveBytesFrom
• System.Net.Socket.TSocket.EndReceiveStringFrom

• System.Net.Socket.TSocket.Receive
• System.Net.Socket.TSocket.ReceiveStringFrom

• send function (MSDN)