NSNotification example

本文详细介绍了如何在iOS应用中使用通知中心实现组件间的解耦通信。通过注册和发送自定义通知,可以轻松地实现不同模块之间的消息传递,提高应用程序的灵活性和可维护性。

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- (void)viewDidLoad {

    [super viewDidLoad];

UIButton *button = [UIButton buttonWithType:102];

button.frame = CGRectMake(50, 50, 100, 30);

[button setTitle:@"Notifaction" forState:UIControlStateNormal];

[button addTarget:self action:@selector(show) forControlEvents:UIControlEventTouchUpInside];

[self.view addSubview:button];

//注册 self 对象,这个对象接收名字是BNRColorChangedNotification 发送者为objcet(object = nil 也就是全部)的notification

 // 当object 发送名字是  BNRColorChangedNotification 的notification是 就回调用 anObserver(self) 的handleColor

NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];

[nc addObserver:self selector:@selector(handleColor:) name:BNRColorChangedNotification object:nil];

NSLog(@"registered!");

}

-(void)handleColor:(NSNotification *)note

{

//处理notification

NSLog(@"Received notification, %@",note);

}

-(void) show

{

NSLog(@"show");

//发送notification 这个notifaction的name是 BNRColorChangedNotification

NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];

[nc postNotificationName:BNRColorChangedNotification object:self];//object post这个notification的对象

NSLog(@"Sending notification");

}


 

 

NSDictionary *dic = [NSDictionary  dictionaryWithObject:array forKey:@"words"];

[nc postNotificationName:BNRColorChangedNotification object:self userInfo:dic ]; //userInfo is NSDictionary , it contains more informations .

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#pragma mark -- UIImagePickerControllerDelegate- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info{ UIImage *pickImage = info[UIImagePickerControllerOriginalImage]; CIDetector *detector = [CIDetector detectorOfType:CIDetectorTypeQRCode context:nil options:@{CIDetectorAccuracy: CIDetectorAccuracyHigh}]; // 获取选择图片中识别结果 NSArray *features = [detector featuresInImage:[CIImage imageWithData:UIImagePNGRepresentation(pickImage)]]; [picker dismissViewControllerAnimated:YES completion:^{ if (features.count > 0) { CIQRCodeFeature *feature = features[0]; NSString *stringValue = feature.messageString; [self handleScanValue:stringValue]; } else { [self readFromAlbumFailed]; } }];}- (void)changeVideoScale:(AVMetadataMachineReadableCodeObject *)objc { NSArray *array = objc.corners; CGPoint point = CGPointZero; int index = 0; CFDictionaryRef dict = (__bridge CFDictionaryRef)(array[index++]); // 把点转换为不可变字典 // 把字典转换为点,存在point里,成功返回true 其他false CGPointMakeWithDictionaryRepresentation(dict, &point); NSLog(@"X:%f -- Y:%f",point.x,point.y); CGPoint point2 = CGPointZero; CGPointMakeWithDictionaryRepresentation((__bridge CFDictionaryRef)array[2], &point2); NSLog(@"X:%f -- Y:%f",point2.x,point2.y); NSLog(@"bounds:%@",NSStringFromCGRect(objc.bounds));}#pragma mark -- App 从后台进入前台- (void)appDidBecomeActive:(NSNotification *)notify { [self resumeScanning];}#pragma mark -- App 从前台进入后台- (void)appWillResignActive:(NSNotification *)notify { [self pauseScanning];}/** 恢复扫一扫功能 */- (void)resumeScanning { if (self.session) { [self.session startRunning]; [self.scannerView startLineAnimation]; }}/** 暂停扫一扫 */- (void)pauseScanning { if (self.session) { [self.session stopRunning]; [self.scannerView stopLineAnimation]; }}#pragma mark -- 扫一扫API/** 处理扫一扫结果 @param value 扫描结果 */- (void)handleScanValue:(NSString *)value { NSLog(@"handleScanValue === %@", value);}/** 相册选取图片无法读取数据 */- (void)readFromAlbumFailed { NSLog(@"readFromAlbumFailed");}- (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated.}@end12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788899091929394959697989910010110210310410510610710810911011111211311411511611711811912012112212312412512612712812913013113213313413513613713813914014114214314414514614714814915015115215315415515615715815916016116216316416516616716816917017117217317417517617717817918018118218318418518618718818919019119219319419519619719819
最新发布
04-03
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