#import <Foundation/Foundation.h>
@class MYOperation;
@protocol MYOperationDelecate <NSObject>
-(void)operationWithStr:(UIImage*)str;
@end
@interface MYOperation : NSOperation
@property(nonatomic,copy)NSString *imageURL;
@property(nonatomic,weak)id<MYOperationDelecate>delegate;
@end
#import "MYOperation.h"
@implementation MYOperation
//必须实现main方法
-(void)main
{
@autoreleasepool {
//模拟下载图片返回的字符串在主进程中返回到控制器进行跟新操作
UIImage*str=[self downloadImage];
[[NSOperationQueue mainQueue]addOperationWithBlock:^{
if([self.delegate respondsToSelector:@selector(operationWithStr:)])
{
[self.delegate operationWithStr:str];
}
}];
};
}
//模拟下载图片
-(UIImage*)downloadImage
{
NSURL *url=[NSURL URLWithString:self.imageURL];
NSData *data=[NSData dataWithContentsOfURL:url];
UIImage*image=[UIImage imageWithData:data];
return image;
}
@end
//控制器加载代码
#import "ViewController.h"
#import "MYOperation.h"
@interface ViewController ()<MYOperationDelecate>
@property(nonatomic,strong)NSOperationQueue*operation;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
MYOperation *operation=[[MYOperation alloc]init];
operation.delegate=self;
operation. imageURL=@"www.baidu.com/image";
[self.operation addOperation:operation];
}
-(void)operationWithStr:(UIImage*)str
{
#warning 在这里实现UI界面的更新
NSLog(@"%@,%@",str,[NSThread currentThread]);
}
-(NSOperationQueue *)operation
{
if(!_operation)
{
_operation=[[NSOperationQueue alloc]init];
[_operation setMaxConcurrentOperationCount:6];
}
return _operation;
}
@end