iOS Development multi-thread nsoperation Nsoperationqueue

<span id="Label3"></p><p><p><span style="font-size: 16px;">-(void) Viewdidload {</span></p></p><p><p><span style="font-size: 16px;">[super viewdidload];</span></p></p><p><p><span style="font-size: 16px;">/*</span></p></p><p><p><span style="font-size: 16px;">Nsoperation and Nsoperationqueue for multithreaded programming</span></p></p><p><p><span style="font-size: 16px;">Step: encapsulate the action performed into the Nsoperation object</span></p></p><p><p><span style="font-size: 16px;">To add a Nsoperation object to the Nsoperationqueue</span></p></p><p><p><span style="font-size: 16px;">The Nsoperation object is removed from the System.</span></p></p><p><p><span style="font-size: 16px;">Putting encapsulated operations into a new thread execution</span></p></p><p><p><span style="font-size: 16px;">Subclass of Nsoperation:</span></p></p><p><p><span style="font-size: 16px;">Nsinvocationoperation Package InitWithTarget:selector:object:</span></p></p><p><p><span style="font-size: 16px;">Execute-start by default when the main thread is added to the queue only new threads are opened and the default is synchronous execution</span></p></p><p><p><span style="font-size: 16px;">Nsblockoperation Create +blockoperationwithblock:^{}</span></p></p><p><p><span style="font-size: 16px;">Add operation-addexecutionblock:^{}; can be added multiple times as long as the encapsulated operation is greater than 1, the asynchronous</span></p></p><p><p><span style="font-size: 16px;">Execute start</span></p></p><p><p><span style="font-size: 16px;">Child definition Inheritance</span></p></p><p><p><span style="font-size: 16px;">Nsoperationqueue function: start can be executed but synchronous, this is asynchronous, as long as added to automate the operation, automatically open the thread</span></p></p><p><p><span style="font-size: 16px;">Method: 1.addoperation:2.addoperationwithblock:^{}</span></p></p><p><p><span style="font-size: 16px;">*/</span></p></p><p><p><span style="font-size: 16px;">/* concurrency number: number of simultaneous tasks performed</span></p></p><p><p><span style="font-size: 16px;">Correlation method for maximum concurrency (typically 2-3 best):-(nsinteger) maxconcurrentoperationcount</span></p></p><p><p><span style="font-size: 16px;">-(void) setmaxconcurrentoperationcount:</span></p></p><p><p><span style="font-size: 16px;">Cancel the operation of the Queue:-(void) canclealloperation</span></p></p><p><p><span style="font-size: 16px;">-(void) cancle</span></p></p><p><p><span style="font-size: 16px;">Pause and resume: when the thread download interface is turned on, it has an impact on the UI and can be paused when the user slides the interface</span></p></p><p><p><span style="font-size: 16px;">-(void) setsuspended:</span></p></p><p><p><span style="font-size: 16px;">-(BOOL) issuspended Current status</span></p></p><p><p><span style="font-size: 16px;">Operation Priority: Set the priority of Nsoperation in queue</span></p></p><p><p><span style="font-size: 16px;">-(nsoperationqueuepriority) queuepriority;</span></p></p><p><p><span style="font-size: 16px;">-(void) setqueuepriority:</span></p></p><p><p><span style="font-size: 16px;">Operation Dependent: [operationb adddependency:operationa]; action B depends on action a, be sure to set before adding to the queue</span></p></p><p><p><span style="font-size: 16px;">Operational monitoring:-completionblock:</span></p></p><p><p><span style="font-size: 16px;">-setcompletionblock:</span></p></p><p><p><span style="font-size: 16px;">Example: operation.completionblock=^{} This code snippet is executed at the end of the previous task</span></p></p><p><p><span style="font-size: 16px;">*/</span></p></p><p><p><span style="font-size: 16px;">}</span></p></p><p><p>iOS Development multi-thread nsoperation Nsoperationqueue</p></p></span>