c++ - Boost.Asio : The difference between async_read and async_receive

Question

async_read 和有什么区别？和 async_receive ?

Answer 1

async_receive 是一个仅接收到缓冲区的函数，但可能无法接收您要求的数量。 (它会相等或更少，永远不会更多。)

但是，

async_read 将始终收到您要求的金额，如其所述:

This function is used to asynchronously read a certain number of bytes of data from a stream. The function call always returns immediately. The asynchronous operation will continue until one of the following conditions is true:

• The supplied buffers are full. That is, the bytes transferred is equal to the sum of the buffer sizes.
• An error occurred.

页面唯一有点模糊的是 async_read 如果它没有得到那么多字节，并且连接正常关闭。 (这算作“错误”吗？)这可以通过快速测试来确定。 (然而，async_receive 只会给你它所得到的。)