Unless, of course, something horrible happens such as a network failure,

/**

 * Just like the sendElement: method above,

 * but allows you to receive a receipt that can later be used to verify the element has been sent.

 * 

 * If you later want to check to see if the element has been sent:

 * 

 * if ([receipt wait:0]) {

 *   // Element has been sent

 * }

 * 

 * If you later want to wait until the element has been sent:

 * 

 * if ([receipt wait:-1]) {

 *   // Element was sent

 * } else {

 *   // Element failed to send due to disconnection

 * }

 * 

 * It is important to understand what it means when [receipt wait:timeout] returns YES.

 * It does NOT mean the server has received the element.

 * It only means the data has been queued for sending in the underlying OS socket buffer.

 * 

 * So at this point the OS will do everything in its capacity to send the data to the server,

 * which generally means the server will eventually receive the data.

 * Unless, of course, something horrible happens such as a network failure,

 * or a system crash, or the server crashes, etc.

 * 

 * Even if you close the xmpp stream after this point, the OS will still do everything it can to send the data.

**/

- (void)sendElement:(NSXMLElement *)element andGetReceipt:(XMPPElementReceipt **)receiptPtr;

转载于:https://www.cnblogs.com/guligei/p/3510414.html