iOS 多線程技術2

iOS 多線程技術2
iOS 多線程技術2NSOperation

NSInvocationOperation

        //建立一個隊列        NSOperationQueue *queue = [[NSOperationQueue alloc] init];        //建立子任務,定義子任務必須是 NSOperation 的子類        NSInvocationOperation *op = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(dosomething:) object:@NSInvocationOperation];        //當把任務添加到隊列後,自動開啟線程        [queue addOperation:op];

NSBlockOperation

            //建立一個隊列        NSOperationQueue *queue = [[NSOperationQueue alloc] init];        //建立 NSBlockOperation 對象        NSBlockOperation *operation = [NSBlockOperation blockOperationWithBlock:^{        [self doSomething];        }];        //排入佇列        [queue addOperat:operation];

Demo:
下面我用NSOperation 的兩種方法來建立一個例子,實現與上篇一樣的功能,

#import ViewController.h---@interface ViewController ()@property (weak, nonatomic) IBOutlet UIImageView *iamgeView;@property (weak, nonatomic) IBOutlet UILabel *lable;@property (nonatomic, strong) NSOperationQueue *queue;@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    // 1.NSInvocationOperation    NSInvocationOperation *op = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(dosomething:) object:@NSInvocationOperation];    op.name = @xiaoming;    NSOperationQueue *queue = [[NSOperationQueue alloc] init];    [queue addOperation:op];    NSLog(@%@,queue.operations);    _queue = queue;}- (void)dosomething:(NSString*)str{  //耗時操作    [NSThread sleepForTimeInterval:3];    //需要在主線程中更新 UI    [self performSelectorOnMainThread:@selector(updateLable:) withObject:str waitUntilDone:YES];}- (void)updateLable:(NSString*)str{    if ([[NSThread currentThread] isMainThread]) {        NSLog(@主線程>>>%s,__func__);    }    _lable.text = str;}- (IBAction)btnAction:(UIButton *)sender {    NSBlockOperation *blockOp = [NSBlockOperation blockOperationWithBlock:^{        //耗時操作        [NSThread sleepForTimeInterval:3];        //建立 url        NSString *urlStr = @http://img.hb.aicdn.com/5a8f57157b47284724d09ffd2da28369731f8144ac9c-1XdZKJ_fw658;        NSURL *url = [NSURL URLWithString:urlStr];        NSData *data = [NSData dataWithContentsOfURL:url];        UIImage *image = [UIImage imageWithData:data];        //更新 UI        [self performSelectorOnMainThread:@selector(updateImageView:) withObject:image waitUntilDone:YES];    }];    [_queue addOperation:blockOp];}- (void)updateImageView:(UIImage*)img{    if ([[NSThread currentThread] isMainThread]) {        NSLog(@主線程>>>>>>%s,__FUNCTION__);    }    _iamgeView.image = img;}@end

運行結果:
2015-08-02 15:03:33.909 05-NSOperationDemo[3284:874300] (
“{name = ‘xiaoming’}”
)
2015-08-02 15:03:36.911 05-NSOperationDemo[3284:874300] 主線程>>>-[ViewController updateLable:]
2015-08-02 15:03:47.730 05-NSOperationDemo[3284:874300] 主線程>>>>>>-[ViewController updateImageView:]