Delphi C++ Indy UDP 服务器 BytesToString 没有收到正确的字符串？

Question

我正在尝试从 TUIO 多模拟器接收 UDP 数据包。但是缺少一些数据。

https://www.tuio.org/?specification

void __fastcall TMain::UDPServerUDPRead(TIdUDPListenerThread *AThread, const TIdBytes AData,
    TIdSocketHandle *ABinding)
{
    UDPData->Lines->Add(BytesToString(AData));

    for (int i = 0; i < AData.Length; i++)
        UDPData->Lines->Add((char)AData[i]);
}

当我使用 BytesToString() 时，我只得到单词 "#bundle" 作为字符串，但是当使用第二个循环时，我得到这个：

# b 你 n d 升 e

/ 吨你一世 o / 2个丁 C 你 r , 秒一世一种升一世 v 电子 4个 / 吨你一世 o / 2个丁 C 你 r , 秒一世 F F F F F 秒电子吨？

ﾎ 9 > ￻ ￚ

/ 吨你一世 o / 2个丁 C 你 r , 秒一世 F 秒电子 q # b 你 n d 升 e

/ 吨你一世 o / 2个丁 o b j , 秒一种升一世 v e

/ 吨你一世 o / 2个丁 o b j , 秒一世 F 秒电子 q # b 你 n d 升 e

/ 吨你一世 o / 2个丁 C 你 r , 秒一种升一世 v e

/ 吨你一世 o / 2个丁 C 你 r , 秒一世 F 秒电子 q

当然，每个字符单独一行。

那么，在不知道编码的情况下，如何获取正确的数据呢？我在这里迷路了，真的需要帮助。

此外，我如何发送与 TIdUDPClient 类似的捆绑包数据？

Answer 1

您显示的 UDP 数据主要是二进制数据，其中包含一些文本元素。因此，您不应该将 entire AData 转换为带有 BytesToString() 的单个字符串，因为它不完全是文本开头（好吧，您可以，使用 BytesToStringRaw() 或 BytesToString() 和 IndyTextEncoding_8bit() 作为编码，但这样做对你帮助不大。

您需要根据 protocol specificiation that you linked to (which in turn is based on the Open Sound Control 协议将数据分解成各个部分。只有这样，您才能根据需要处理组件。这意味着您需要逐字节循环 AData，根据协议在上下文中解析每个字节。

例如（到目前为止，这还不是一个完整的实现，但它应该让您了解所涉及的逻辑类型）：

struct OSCArgument
{
    char Type;
    Variant Data;
}

struct OSCBundleElement
{
    virtual ~OSCBundleElement() {}
};

struct OSCMessage : OSCBundleElement
{
    String AddressPattern;
    DynamicArray<OSCArgument> Arguments;
};

struct OSCBundle : OSCBundleElement
{
    TDateTime TimeTag;
    DynamicArray<OSCBundleElement*> Elements;

    ~OSCBundle()
    {
        int len = Elements.Length;
        for (int i = 0; i < len; ++i)
            delete Elements[i];
    }
};

int32_t readInt32(const TIdBytes &Bytes, int &offset)
{
    uint32_t ret = GStack->NetworkToHost(BytesToUInt32(Bytes, offset));
    offet += 4;
    return reinterpret_cast<int32_t&>(ret);
}

TDateTime readOSCTimeTag(const TIdBytes &Bytes, int &offset)
{
    int32_t secondsSinceEpoch = readInt32(Bytes, offset); // since January 1 1900 00:00:00
    int32_t fractionalSeconds = readInt32(Bytes, offset); // precision of about 200 picoseconds
    // TODO: convert seconds to TDateTime...
    TDateTime ret = ...;
    return ret;
}

float readFloat32(const TIdBytes &Bytes, int &offset)
{
    uint32_t ret = BytesToUInt32(Bytes, offset);
    offet += 4;
    return reinterpret_cast<float&>(ret);
}

String readOSCString(const TIdBytes &Bytes, int &offset)
{
    int found = ByteIndex(0x00, Bytes, offset);
    if (found == -1) throw ...; // error!
    int len = found - offset;
    String ret = BytesToString(Bytes, offset, len, IndyTextEncoding_ASCII());
    len = ((len + 3) & ~3)); // round up to even multiple of 32 bits
    offset += len;
    return ret;
}

TIdBytes readOSCBlob(const TIdBytes &Bytes, int &offset)
{
    int32_t size = readInt32(Bytes, offset);
    TIdBytes ret;
    ret.Length = size;
    CopyTIdBytes(Bytes, offset, ret, 0, size);
    size = ((size + 3) & ~3)); // round up to even multiple of 32 bits
    offset += size;
    return ret;
}

OSCMessage* readOSCMessage(const TIdBytes &Bytes, int &offset);
OSCBundle* readOSCBundle(const TIdBytes &Bytes, int &offset);

OSCBundleElement* readOSCBundleElement(const TIdBytes &Bytes, int &offset)
{
    TIdBytes data = readOSCBlob(Bytes, offset);
    int dataOffset = 0;

    switch (data[0])
    {
        case '/': return readOSCMessage(data, dataOffset); 
        case '#': return readOSCBundle(data, dataOffset);
    }

    throw ...; // unknown data!
}

Variant readOSCArgumentData(char ArgType, const TIdBytes &Bytes, int &offset)
{
    switch (ArgType)
    {
        case 'i': return readInt32(Bytes, offset);
        case 'f': return readFloat32(Bytes, offset);
        case 's': return readOSCString(Bytes, offset);
        case 'b': return readOSCBlob(Bytes, offset);
        // other types as needed ...
    }

    throw ...; // unknown data!
}

OSCMessage* readOSCMessage(const TIdBytes &Bytes, int &offset)
{
    OSCMessage* ret = new OSCMessage;
    try
    {
        ret->AddressPattern = readOSCString(Bytes, offset);

        String ArgumentTypes = readOSCString(Bytes, offset);
        if (ArgumentTypes[1] != ',') throw ...; // error!

        for (int i = 2; i <= ret->ArgumentTypes.Length(); ++i)
        {
            OSCArgument arg;
            arg.Type = ArgumentTypes[i];
            arg.Data = readOSCArgumentData(arg.Type, Bytes, offset);

            ret.Arguments.Length = ret.Arguments.Length + 1;
            ret.Arguments[ret.Arguments.High] = arg;
        }
    }
    catch (...)
    {
        delete ret;
        throw;
    }

    return ret;
}

OSCBundle* readOSCBundle(const TIdBytes &Bytes, int &offset)
{
    if (readOSCString(Bytes, offset) != "#bundle")
        throw ...; // error!

    OSCBundle *ret = new OSCBundle;
    try
    {
        ret->TimeTag = readOSCTimeTag(Bytes, offset);

        int len = Bytes.Length;
        while (offset < len)
        {
            OSCBundleElement *element = readOSCBundleElement(Bytes, offset);
            try
            {
                ret->Elements.Length = ret->Elements.Length + 1;
                ret->Elements[ret->Elements.High] = element;
            }
            catch (...)
            {
                delete element;
                throw;
            }
        }
    }
    catch (...)
    {
        delete ret;
        throw;
    }

    return ret;
}

void __fastcall TMain::UDPServerUDPRead(TIdUDPListenerThread *AThread, const TIdBytes AData,
    TIdSocketHandle *ABinding)
{
    int offset = 0;

    if (AData[0] == '/')
    {
        OSCMessage *msg = readOSCMessage(AData, offset);
        // process msg as needed...
        delete msg;
    }
    else if (AData[0] == '#')
    {
        OSCBundle *bundle = readOSCBundle(AData, offset); 
        // process bundle as needed...
        delete bundle;
    }
    else
    {
        // unknown data!
    }
}

Delphi C++ Indy UDP 服务器 BytesToString 没有收到正确的字符串？

Delphi C++ Indy UDP Server BytesToString does not receive correct string?

delphi

udp

indy

c++builder