GCD,NSThread,NSOperation
为了方便看, 定义三个button:
// ViewController.h
#import
@interface ViewController : UIViewController
@property (nonatomic, retain) UIImageView *MyimageView;
@end
// ViewController.m
#import "ViewController.h"
@interface ViewController ()
@end
@implementation ViewController
1.定义三个按钮
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
UIButton *button1 = [UIButton buttonWithType:UIButtonTypeCustom];
button1.frame = CGRectMake(60, 40, 200, 40);
[button1 setTitle:@"NSThread" forState:UIControlStateNormal];
button1.backgroundColor = [UIColor orangeColor];
[self.view addSubview:button1];
[button1 addTarget:self action:@selector(button1Action:) forControlEvents:UIControlEventTouchUpInside];
UIButton *button2 = [UIButton buttonWithType:UIButtonTypeCustom];
button2.frame = CGRectMake(60, 100, 200, 40);
[button2 setTitle:@"NSOperation" forState:UIControlStateNormal];
button2.backgroundColor = [UIColor greenColor];
[self.view addSubview:button2];
[button2 addTarget:self action:@selector(button2Action:) forControlEvents:UIControlEventTouchUpInside];
UIButton *button3 = [UIButton buttonWithType:UIButtonTypeCustom];
button3.frame = CGRectMake(60, 160, 200, 40);
[button3 setTitle:@"GCD" forState:UIControlStateNormal];
button3.backgroundColor = [UIColor cyanColor];
[self.view addSubview:button3];
[button3 addTarget:self action:@selector(button3Action:) forControlEvents:UIControlEventTouchUpInside];
self.MyimageView = [[UIImageView alloc] initWithFrame:CGRectMake(60, 300, 200, 200)];
[self.view addSubview:self.MyimageView];
self.MyimageView.backgroundColor = [UIColor lightGrayColor];
}
- (void)DownLoadImage
{
NSString *urlStr = @"http://amuse.nen.com.cn/imagelist/11/21/9as70n3ir61b.jpg";
NSURL *url = [NSURL URLWithString:urlStr];
NSData *data = [NSData dataWithContentsOfURL:url];
UIImage *image = [UIImage imageWithData:data];
}
#pragma mark -- 多线程之 NSThread
- (void)button1Action:(UIButton *)button1
{
// NSLog(@"aa");
// 自定义多线程
NSThread *thread = [[NSThread alloc] initWithTarget:self selector:@selector(action:) object:@"大水杯"];
// 开启多线程
[thread start];
// 使用系统的
[NSThread detachNewThreadSelector:@selector(DownLoadImage) toTarget:self withObject:nil];
NSLog(@"当前线程为 %@ 是否为主线程 %d", [NSThread currentThread], [NSThread isMainThread]);
}
- (void)action1
{
NSLog(@"action1");
}
- (void)action:(NSString *)str
{
NSLog(@"当前线程为 %@ 是否为主线程 %d", [NSThread currentThread], [NSThread isMainThread]);
NSLog(@"str = %@", str);
// for (int i = 0; i < 1000000; i++) {
// NSLog(@"i = %d", i);
// }
}
#pragma mark -- 多线程之 NSOperation
- (void)button2Action:(UIButton *)button2
{
// NSLog(@"bb");
// NSOperation 是抽象类 我是用它提供的两个子类
NSInvocationOperation *operation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(action:) object:@"大水表"];
NSInvocationOperation *operation1 = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(action1) object:nil];
NSBlockOperation *blockOperation = [NSBlockOperation blockOperationWithBlock:^{
for (int i = 0; i < 100; i++) {
NSLog(@"i = %d", i);
}
}];
// 队列 用来管理队列里的一个或多个任务
NSOperationQueue *queue = [[NSOperationQueue alloc] init];
// 最大允许并发执行任务的个数
[queue setMaxConcurrentOperationCount:2];
// 绑定一个任务 就是前者必须等到后者执行完才能执行
[operation addDependency:blockOperation];
// 将任务加到队列中
[queue addOperation:operation];
[queue addOperation:operation1];
[queue addOperation:blockOperation];
}
CGD的使用.分为串行和并行, 为了避免之间的影响, 有一些地方注释了,可根据需要自行解开
- (void)button3Action:(UIButton *)button3
{
#pragma mark -- GCD之串行 serial
// NSLog(@"cc");
// 串行特点 一个一个执行, 一个执行完在执行下一个
// 1.系统自带串行队列
// 1.1 创建系统主队列
#warning 重点经常用到, 作用:从子线程上得到主线程
/*
dispatch_queue_t mainQueue = dispatch_get_main_queue();
// 1.2 执行主队列
dispatch_async(mainQueue, ^{
// NSLog(@"1 = %@ %d", [NSThread currentThread], [NSThread isMainThread]);
// NSLog(@"2 = %@ %d", [NSThread currentThread], [NSThread isMainThread]);
// NSLog(@"3 = %@ %d", [NSThread currentThread], [NSThread isMainThread]);
});
*/
#warning 重要 非常常见的写法
/*
dispatch_async(dispatch_get_main_queue(), ^{
NSLog(@"获得主线程的大众写法");
});
*/
// 2.自定义串行队列
// 2.1 创建自定义串行队列
// 参数1. 队列标识符 一般是逆向域名
// 参数2.队列类型
/* dispatch_queue_t mySerialQueue = dispatch_queue_create("com.lanou3g.GCD.Serial", DISPATCH_QUEUE_SERIAL);
*/
// 2.2 执行队列
/*
dispatch_async(mySerialQueue, ^{
NSLog(@"1 = %@ %d", [NSThread currentThread], [NSThread isMainThread]);
NSLog(@"2 = %@ %d", [NSThread currentThread], [NSThread isMainThread]);
NSLog(@"3 = %@ %d", [NSThread currentThread], [NSThread isMainThread]);
NSLog(@"4 = %@ %d", [NSThread currentThread], [NSThread isMainThread]);
});
*/
#pragma mark -- GCD之 并行
#warning 重要 经常跟dispatch_get_main_queue 一起使用
// 1.得到全局队列
// 参数1.队列优先级
// 参数2.苹果预留参数,默认给0
/*
dispatch_queue_t globalQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
// 2. 执行队列
dispatch_sync(globalQueue, ^{
NSLog(@"1 = %@ %d", [NSThread currentThread], [NSThread isMainThread]);
});
dispatch_sync(globalQueue, ^{
NSLog(@"2 = %@ %d", [NSThread currentThread], [NSThread isMainThread]);
});
dispatch_sync(globalQueue, ^{
NSLog(@"3 = %@ %d", [NSThread currentThread], [NSThread isMainThread]);
});
*/
// 自定义并行队列
// 1.创建自定义并行队列
/*
dispatch_queue_t myConcurrentQueue = dispatch_queue_create("com.lanou3g.GCD.ConCurrentQueue", DISPATCH_QUEUE_CONCURRENT);
// 执行队列
dispatch_async(myConcurrentQueue, ^{
NSLog(@"1 = %@ %d", [NSThread currentThread], [NSThread isMainThread]);
});
dispatch_async(myConcurrentQueue, ^{
NSLog(@"2 = %@ %d", [NSThread currentThread], [NSThread isMainThread]);
});
dispatch_async(myConcurrentQueue, ^{
NSLog(@"3 = %@ %d", [NSThread currentThread], [NSThread isMainThread]);
});
*/
#warning 重要
// 练习 子线程请求图片 主线程负责刷新显示图片
// 1.dispatch_get_global_queue 创建系统并行队列
// 2.dispatch_async 执行队列
/* dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
// 此块中是子线程
NSString *urlStr = @"http://amuse.nen.com.cn/imagelist/11/21/9as70n3ir61b.jpg";
NSURL *url = [NSURL URLWithString:urlStr];
NSData *data = [NSData dataWithContentsOfURL:url];
UIImage *image = [UIImage imageWithData:data];
// block里不要用self
__block ViewController *vc = self;
// 在主线程中显示图片
dispatch_async(dispatch_get_main_queue(), ^{
vc.MyimageView.image = image;
});
});
*/
#warning 重要
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(5.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
NSLog(@"%@ %d", [NSThread currentThread], [NSThread isMainThread]);
});
// 2.只执行一次
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
NSLog(@"2 %@ %d", [NSThread currentThread], [NSThread isMainThread]);
});
}