Multi-threaded usage in IOS development

One, five ways to create multi-threading

1. How to turn on threading

    object: nil];

2. How to turn on threading method two

    [Nsthread detachnewthreadselector: @selector (_update) totarget:self Withobject:nil];

3. How to turn on threading three

    [Self Performselectorinbackground: @selector (_update) Withobject:nil];

4. How to turn on threading four

    Nsoperationqueue *queue=[[Nsoperationqueue alloc] init];    [Queue addoperationwithblock:^{        for (int i=0;i<; i++ {            printf (" sub-thread \ n");}    }];

5. How to turn on threading five

    //The first step is to turn on the thread poolNsoperationqueue * queue=[[Nsoperationqueue alloc] init]; //set number of concurrent[Queue Setmaxconcurrentoperationcount:2]; //Second Create multithreaded add to thread poolNsinvocationoperation * Thread1=[[nsinvocationoperation alloc] initwithtarget:self selector: @selector (_update1)Object: nil]; Nsinvocationoperation*thread2=[[nsinvocationoperation Alloc] initwithtarget:self selector: @selector (_UPDATE2)Object: nil];    [Thread1 Setqueuepriority:nsoperationqueuepriorityverylow];        [Thread2 Setqueuepriority:nsoperationqueuepriorityveryhigh];    [Queue Addoperation:thread1]; [Queue addoperation:thread2];

Second, multi-threaded application examples, loading pictures.

1. Core Ideas

Consider that if loading a network picture is delayed, in one mainline preempted will affect the rendering of the control, at which point you can take multi-threading and refresh the UI after the asynchronous loading is complete.

2. Realization of Ideas

Multi-threaded downloads are achieved by adding classes to the Uiimageview.

　　Main code:

" uiimageview+thread.h " @implementation uiimageview (load)-(void) Setimagewithurl: (NSString *) url{    [self Performselectorinbackground: @selector (_loadimage:) Withobject:url];} -(void) _loadimage: (NSString *) u{    @autoreleasepool {                *url=[Nsurl urlwithstring:u];        *data=[NSData Datawithcontentsofurl:url];         *image=[UIImage imagewithdata:data];                [Self Performselectoronmainthread: @selector (setimage:) withobject:image waituntildone:no];            }}

Jerry Education
Source:http://www.cnblogs.com/jerehedu/
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Multi-threaded usage in IOS development