IOS multithreading _ NSThread and NSInvocationOperation

IOS multithreading _ NSThread and NSInvocationOperation

// Although most of the threads are currently using GCD, we should be familiar with other methods to introduce the simple usage of NSThread and NSInvocationOperation.

@ InterfaceyxpViewController ()

{

UIImageView * _ imageView;

// Declare a queue

NSOperationQueue * _ operationQueue;

}

@ End

@ Implementation yxpViewController

-(Void) viewDidLoad

{

[SuperviewDidLoad];

// Initialize the operation queue

_ OperationQueue = [[NSOperationQueuealloc] init];

// This limits the queue to run only one thread at a time

[_ OperationQueuesetMaxConcurrentOperationCount: 1];

// Initialize an _ ImageView

_ ImageView = [[UIImageViewalloc] initWithFrame: CGRectMake (300,450,)];

_ ImageView. backgroundColor = [UIColorgrayColor];

_ ImageView. animationDuration = 3.0;

_ ImageView. animationRepeatCount = 0;

[Self. viewaddSubview: _ imageView];

// The following two methods add a thread

// First

// Create an NSInvocationOperation object and initialize it to the Method

// Here, the value after the selector parameter is the Method (function, Method) You want to run in another thread)

// Here, the object value is the data to be passed to the previous method.

NSInvocationOperation * theOp = [[NSInvocationOperationalloc] initWithTarget: selfselector: @ selector (addTaskMethod :) object: _ imageView];

// Of course, you can also choose to directly call the start method, but this sample is synchronous, that is, the main thread must be executed after the background thread execution is complete.

// [TheOp start];

// Operation is added to the queue for theOp and the main thread to execute at the same time, that is, the asynchronous thread, in order to achieve our results

[_ OperationQueueaddOperation: theOp];

// Type 2

// Use [NSThread detachNewThreadSelector: @ selector (addTaskMethod :) toTarget: self withObject: nil]; you can also add a thread which is equivalent to the previous one.

// [NSThread detachNewThreadSelector: @ selector (addTaskMethod :) toTarget: self withObject: nil];

}

// Method for running another thread

-(Void) addTaskMethod :( id) data

{

NSString * url1 = @ "http://h.hiphotos.baidu.com/image/w%3D230/sign=b2d5c289123853438ccf8022a311b01f/91ef76c6a7efce1b1ae9f92fad51f3deb58f6510.jpg ";

NSString * url2 = @ "http://h.hiphotos.baidu.com/image/pic/item/d058ccbf6c81800aae834e8bb33533fa838b47d5.jpg ";

NSString * url3 = @ "http://d.hiphotos.baidu.com/image/pic/item/f2deb48f8c5494eec3ba65132ff5e0fe99257e1b.jpg ";

NSString * url4 = @ "http://g.hiphotos.baidu.com/image/pic/item/a6efce1b9d16fdfa81f4ace4b68f8c5494ee7b1b.jpg ";

NSString * url5 = @ "http://g.hiphotos.baidu.com/image/pic/item/d6ca7bcb0a46f21f70031fdbf4246b600c33ae07.jpg ";

NSArray * array = [[NSArrayalloc] initWithObjects: url1, url2, url3, url4, url5, nil];

NSMutableArray * imageArray = [[NSMutableArrayalloc] initWithCapacity: 20];

For (NSString * stringin array ){

UIImage * image = [selfgetImageFromURL: string];

[ImageArrayaddObject: image];

}

_ ImageView. animationImages = imageArray;

// Return to the main thread for calling methods related to the UI thread (main thread) that cannot be called in a non-thread. You can call the method directly to check whether the method is valid.

[Self?mselec=mainthread: @ selector (startImageViewAnimating) withObject: nilwaitUntilDone: YES];

}

-(Void) startImageViewAnimating

{

[_ ImageView startAnimating];

}

// Method for downloading images

-(UIImage *) getImageFromURL :( NSString *) fileURL {

NSLog (@ "execute image download function ");

UIImage * result;

NSData * data = [NSDatadataWithContentsOfURL: [NSURLURLWithString: fileURL];

Result = [UIImageimageWithData: data];

Return result;

}

-(Void) didReceiveMemoryWarning

{

[SuperdidReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

@ End