#import "ViewController.h"
@interface ViewController ()
@property(nonatomic,strong)NSData *data;
@property (weak, nonatomic) IBOutlet UIImageView *imageview;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
}
//主线程回调事件
-(void)updateUi{
NSLog(@"刷新UI");
self.imageview.image =[UIImage imageWithData:self.data];
}
//手动开启线程
- (IBAction)manual:(UIButton *)sender {
NSThread *thread =[[NSThread alloc]initWithTarget:self selector:@selector(threadtest) object:nil];
//开启线程
[thread start];
//结束线程有2种方式:
//取消线程;
[thread cancel];
//立即结束线程
[NSThread exit];
//判断一个线程是否正在执行
[thread isExecuting];
//判断一个线程是否完成了任务
[thread isFinished];
}
//自动开启线程
- (IBAction)outotNSthread:(UIButton *)sender {
[NSThread detachNewThreadSelector:@selector(threadtest) toTarget:self withObject:nil];
NSLog(@"zouni");
}
//线程执行事件
-(void)threadtest{
//线程一定加autorealeasepool
//如果一个任务在子线程中执行,我们需要在任务里面添加autorealeasepool:原因:因为线程与线程之间是相互独立的,但是资源确实共享的在任务里可能会创建多个对象(在堆区开辟)如果没有释放的话,其他线程也无法访问和使用这个开辟的空间;
//主要是针对 在线称执行的任务中,大量使用便利构造器创建对象的时候,可能会造成很多堆区内存无法释放,导致内存泄漏问题.
@autoreleasepool {
//现获取当前线程
NSLog(@" 当前线程%@",[NSThread currentThread]);
//判断是不是主线程
NSLog(@"是不是主线程%d",[[NSThread currentThread]isMainThread]);
// NSInteger count =0;
// for (int i=0; i<1000000000; i++) {
// count +=i;
//
// }
// NSLog(@"%ld",(long)count);
self.data =[NSData dataWithContentsOfURL:[NSURL URLWithString:@"http://pic.nipic.com/2007-11-09/200711912453162_2.jpg"]];
}
//回到主线程
[self performSelectorOnMainThread:@selector(updateUi) withObject:nil waitUntilDone:nil];
}
//nsobject主线程
- (IBAction)mainNSobject:(UIButton *)sender {
//在主线程中执行某个方法
[self performSelectorOnMainThread:@selector(threadtest) withObject:nil waitUntilDone:YES];
}
//bsobject子线程
- (IBAction)childthread:(UIButton *)sender {
//在子线称重执行某个事件
[self performSelectorInBackground:@selector(threadtest) withObject:nil];
}
- (IBAction)buttion1:(id)sender {
int count =0;
for (int i=0; i<1000000; i++) {
count += i;
}
NSLog(@"当前线程是:%@,是不是主线程%d",[NSThread currentThread],[[NSThread currentThread] isMainThread]);
NSLog(@"%d",count);
}
