將未簽名的short / int強制轉換為char *

Question

我有這樣的功能

void UnitTestWorker::constructTestPayload(QByteArray &payload)
{
    QString List = "127.0.0.1";
    unsigned short Port = 12344;
    unsigned int RequestId = 1;
    memcpy(payload.data(),reinterpret_cast<char*>Port,sizeof(Port));
    memcpy(payload.data()+sizeof(Port),reinterpret_cast<char*>RequestId ,sizeof(RequestId ));
}

但是我遇到訪問沖突錯誤，似乎我無法執行諸如reinterpret_cast<char*>Port或reinterpret_cast<char*>RequestId 。

Answer 1

您必須確保QByteArray &payload具有足夠的大小來接收字節復制到它的數據：

if (payload.size()<sizeof(Port)+sizeof(RequestId)) 
    throw exception ("Ouch !! payload too small"); 
memcpy(payload.data(),reinterpret_cast<char*>(&Port),sizeof(Port));
memcpy(payload.data()+sizeof(Port),reinterpret_cast<char*>(&RequestId) ,sizeof(RequestId ));