An Egyptian put his ear to the ground. He 1 . the horses coming this way. He ran to 2. his people . He was a 3. . That was one way for Egyptians to send messages.
People in 4 countries sent message, too. When enemies came, one man beat his drum. In the next village people heard the drum and beat their drums, too. The messages went from village to village by 5..
Much 6. , some armies (军队) kept many pigeons(鸽子) . These pigeons always 7. back. When a soldier was sent far away from his own 8. , he might take a pigeon along. He could tie a message to the bird’s leg. It would fly back 9. the soldier’s message.
These are shown ways to send messages. Can you think of more 10
The Time Traveller (for so it will be convenient to speak of him) was expounding a recondite matter to us. His grey eyes shone and twinkled, and his usually pale face was flushed and animated. The fire burned brightly, and the soft radiance of the incandescent lights in the lilies of silver caught the bubbles that flashed and passed in our glasses. Our chairs, being his patents, embraced and caressed us rather than submitted to be sat upon, and there was that luxurious after-dinner atmosphere when thought roams gracefully free of the trammels of precision. And he put it to us in this way--marking the points with a lean forefinger--as we sat and lazily admired his earnestness over this new paradox (as we thought it:) and his fecundity.
`You must follow me carefully. I shall have to controvert one or two ideas that are almost universally accepted. The geometry, for instance, they taught you at school is founded on a misconception.'
`Is not that rather a large thing to expect us to begin upon?' said Filby, an argumentative person with red hair.
`I do not mean to ask you to accept anything without reasonable ground for it. You will soon admit as much as I need from you. You know of course that a mathematical line, a line of thickness NIL, has no real existence. They taught you that? Neither has a mathematical plane. These things are mere abstractions.'
`That is all right,' said the Psychologist.
`Nor, having only length, breadth, and thickness, can a cube have a real existence.'
`There I object,' said Filby. `Of course a solid body may exist. All real things--'
The simplest version is SendMessage itself, which sends a message and waits indefinitely for the response.
The next level up is SendMessageTimeout which sends a message and waits for the response or until a certain amount of time has elapsed. SendMessage is just SendMessageTimeout with an INFINITE timeout.
Another version of SendMessage is SendNotifyMessage, which is like SendMessage except that it doesn't wait for the response. It returns immediately and ignores the result produced by the receiving window.
The last SendMessage-style functions is SendMessageCallback. This sends a message and then returns immediately. When the recipient finally returns a response, the callback is called.
SendNotifyMessage is SendMessageCallback with a callback that does nothing.
That's how the four message-sending functions fit together.
Bonus remark: If you use any of the above send-type functions to send a message to a window that belongs to the sending thread, the call is made synchronously.