[多线程之二]－NSOperation练习

来源：互联网发布：学声乐的软件编辑：程序博客网时间：2024/06/07 09:24

#import <UIKit/UIKit.h>@interface ViewController : UIViewController@property (strong, nonatomic) IBOutlet UIImageView *MainImgView;@property (strong, nonatomic) IBOutlet UIImageView *BlockImgView;@end

#import "ViewController.h"@interface ViewController ()@end@implementation ViewController- (void)viewDidLoad {    NSURL* url = [[NSURL alloc] initWithString:@"http://avatar.csdn.net/3/0/F/1_liyanq528.jpg"];    //注意1:NSInvocationOperation这个只能传一个参数    //注意2:NSInvocationOperation直接调用的话，是放在主线程调用，只有用queue里面才是其他线程调用。    NSInvocationOperation* operat = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(downLoadImg:) object:url];    [operat setCompletionBlock:^{        NSLog(@"MainImgView图像更新完成");    }];    //注意3:NSBlockOperation直接调用只有一个block，是放在主线程调用。有多个block,或者放入queue里面，就可以其他线程调用    NSBlockOperation* bOperat = [NSBlockOperation blockOperationWithBlock:^{        NSData* data = [[NSData alloc] initWithContentsOfURL:url];        if (data) {            UIImage* img = [[UIImage alloc] initWithData:data];            NSLog(@"%@",[NSThread currentThread]);            dispatch_async(dispatch_get_main_queue(), ^{                self.BlockImgView.image = img;            });            //[self performSelectorOnMainThread:@selector(updateImg:) withObject:img waitUntilDone:NO];        }    }];    [bOperat setCompletionBlock:^{        NSLog(@"BlockImgView图像更新完成");    }];    NSOperationQueue* que = [[NSOperationQueue alloc]init];    //注意4:并发的线程数量不宜过多，最好5以内，否则会影响ui    [que setMaxConcurrentOperationCount:3];    [que addOperation:operat];    [que addOperation:bOperat];    [super viewDidLoad];    // Do any additional setup after loading the view, typically from a nib.}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}-(void) updateImg:(UIImage*) aimg{    self.MainImgView.image = aimg;}-(void) downLoadImg:(NSURL*) aurl{    NSData* data = [[NSData alloc] initWithContentsOfURL:aurl];    if (data) {        UIImage* img = [[UIImage alloc] initWithData:data];        dispatch_async(dispatch_get_main_queue(), ^{            self.MainImgView.image = img;        });        //[self performSelectorOnMainThread:@selector(updateImg:) withObject:img waitUntilDone:NO];    }}@end

参考：http://www.cnblogs.com/wendingding/p/3809042.html

0 0