iOS--Objc

注：在OC中并没有abstract class的概念，只有protocol，如果在基类中只定义接口(没有具体方法的实现)，则可以使用protocol，这样会更方便。

创建一个NSObject的类别称为“创建一个非正式协议”，任何类的对象都可以作为委托对象使用，既不需要从特定的serviceBrowserDelegate类中继承（如C++中那样），也不需要符合某种特定的接口（如在java中那样）。——摘自《Objective-C基础教程》的p187。

char a[20] -> NSString

char* str -> NSString

NSString* deviceName = [NSString stringWithFormat:@"%s", mcPeripheral.deviceInfo.deviceName];//以'\0'结尾的
NSString* password = [[NSString alloc] initWithData:[NSData dataWithBytes:(const void *)mcPeripheral.deviceInfo.password length:sizeof(mcPeripheral.deviceInfo.password)] encoding:NSASCIIStringEncoding];;//不以'\0'结尾的
NSLog(@" [ 008 ] hardwareID = %@, deviceName = %@, password = %@", hardwareID, deviceName, password);

NSData --> NSString

NSMutableData *data;  //NSData *data;
NSString *tmpdata=[[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];
NSString* hardwareID = [[NSString alloc] initWithData:mcPeripheral.hardwareID encoding:NSASCIIStringEncoding];//不以'\0'结尾的

NSSting --> NSData

    NSString * str=@"test string";
    NSData *data=[str dataUsingEncoding:NSUTF8StringEncoding];

retain并未创建新对象，只是对象的生命值改变

类A中定义了一个delegate。

-(void) getDevicePlist
{
    self.devicePlistMainCtrl = [self _readDevicePlist];
    
    NSLog(@"[006] %@",self.devicePlistMainCtrl);
    
    //delegate通知上层应用
    if ([self.delegate respondsToSelector:@selector(didDevicePlistChanged:)]) {
        [self.delegate performSelector:@selector(didDevicePlistChanged:) withObject:self.devicePlistMainCtrl];
    }
    
    NSLog(@"[005] %@",self.devicePlistMainCtrl);
    
}

下面是再另外一个类B中对上面类A的delegate的实现：

#pragma mark - DevicePlistDelegate
- (void) didDevicePlistChanged:(NSMutableDictionary*) devicePlistMainCtrl
{
    //这里对出入的dict进行了retain，但是其实还是指向的同一个dict，所以在类B中对self.devicePlistMainCtrl的任何操作，都会影响类A中的该dict。
    self.devicePlistMainCtrl = devicePlistMainCtrl;

    //在类B中删除了dict的一个key，在类A中的［005］和［006］处打印可以看出。
    [self.devicePlistMainCtrl removeObjectForKey:DEVICE_KEY_USERNAME];

}

NSArray的升序或者降序排列

需要对一个NSDictionary的key进行排序（降序或者升序），我们应该如何做呢？注意- (NSArray *)allKeys函数返回的数组是没有顺序的。我们可以对该数组进行排序，数组的降序或者升序排列使用下面的方法。

    NSSortDescriptor* sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:nil ascending:NO selector:@selector(localizedCompare:)];
    //降序排列
    NSArray* sortedArrayDescending = [[self.configItems allKeys] sortedArrayUsingDescriptors:[NSArray arrayWithObject:sortDescriptor]];
    //升序排列 
    NSArray *sortedArrayAscending = [[self.configItems allKeys] sortedArrayUsingSelector:@selector(compare:)];
    
    NSLog(@"descending: %@",sortedArrayDescending);
    NSLog(@"ascending: %@",sortedArrayAscending);

-(NSNumber*)postDeviceToken:(NSString*)deviceToken
{
    // unix时间字符串
    NSString *datestr = [NSString stringWithFormat:@"%0.f",[[NSDate date] timeIntervalSince1970]];;
    
    NSString* nonce = [self nonce];
    ....
}



- (NSString *)nonce
{
    // 随机20个字符，字符可以为不可见字符，0 ～ 255，需要使用urlencode
    NSMutableString *randstr = [NSMutableString stringWithCapacity:20];
    for(int i = 0 ; i < 20 ; i++)
    {
        uint8_t thisChar = arc4random()%0xff;
        
        if (thisChar == '.' || thisChar == '-' || thisChar == '_' || thisChar == '~' ||
            (thisChar >= 'a' && thisChar <= 'z') ||
            (thisChar >= 'A' && thisChar <= 'Z') ||
            (thisChar >= '0' && thisChar <= '9')) {
            [randstr appendFormat:@"%c", thisChar];
        } else {
            NSString *tmp = [NSString stringWithFormat:@"%%%02X", thisChar];
            tmp = [tmp uppercaseString];
            [randstr appendString:tmp];
        }
    }
    
    return randstr;
}

清空数组对象

清空已经发现的BLE外设数组，清空已经已经获得deviceInfo信息的BLE外设数组


foundPeripherals = nil;
authenPeripherals = nil;

authenPeripherals是NSMutableArray数组对象，对其清空不能够直接付值nil，而应该使用对象的方法。


[authenPeripherals removeAllObjects];

成员变量的初始化


@interface LoginRegist:NSObject {
    MainControllerPeripheral* _connectedMainCtrl;
    
    //统计字段
    NSString* _type;
    NSString* _appVersion;
    NSString* _sysVersion;
    NSString* _language;
    NSString* _locale;
    NSString* _sysDeviceID;
    NSString* _sysDeviceType;
    NSString* _command;
    
}

- (id) init {
    
    if (self = [super init]) {
        
        //这样是不正确的，在init这个scope之外，所有在此声明的NSString都已经销毁了，成员指针都变成了野指针。
	_type = [NSString stringWithFormat:@"assistant"];
	_command = [NSString stringWithFormat:@"connected"];
	_appVersion = [NSString stringWithFormat:@"1.0.0"];
	_sysVersion = [[UIDevice currentDevice] systemVersion];
	_language = [[NSLocale preferredLanguages] objectAtIndex:0];
	

	//这样才正确，使用alloc函数
        _type = [[NSString alloc] initWithFormat:@"assistant"];
        _command = [[NSString alloc] initWithFormat:@"connected"];
        _appVersion = [[NSString alloc] initWithFormat:@"1.0.0"];
        _sysVersion = [[[UIDevice currentDevice] systemVersion] retain];
        _language = [[[NSLocale preferredLanguages] objectAtIndex:0] retain];
        _locale = [[NSString alloc] initWithFormat:@"china"];
        _sysDeviceID = [[NSString alloc] initWithFormat:@"abcdddd"];
        
    	......
    }
    
    return self;
    
}

2013-07-15 23:04:10.825 IRRemoteControl[8301:907] <00000000> 2013-07-15 23:04:10.828 IRRemoteControl[8301:907] -[NSConcreteValue integerValue]: unrecognized selector sent to instance 0x1d8832e0 2013-07-15 23:04:10.831 IRRemoteControl[8301:907] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSConcreteValue integerValue]: unrecognized selector sent to instance 0x1d8832e0' *** First throw call stack: (0x320172a3 0x39cfb97f 0x3201ae07 0x32019531 0x31f70f68 0x5c179 0x33e86311 0x33e9279b 0x33e924c1 0x33e634e9 0x33e22803 0x33bccd8b 0x33bcc929 0x33bfb7cf 0x33ecc0e9 0x33ecb2d5 0x33eca4a7 0x33eca431 0x34000309 0x33e88691 0x33e883d5 0x33e87d3b 0x33e7eeab 0x33e7aaed 0x33ebc1e9 0x5af47 0x33e7fad9 0x33e7f663 0x33e7784b 0x33e1fc39 0x33e1f6cd 0x33e1f11b 0x35b265a3 0x35b261d3 0x31fec173 0x31fec117 0x31feaf99 0x31f5debd 0x31f5dd49 0x33e76485 0x33e73301 0x5ac37 0x3a132b20) libc++abi.dylib: terminate called throwing an exception

int count = 0; for (int i = 0; i < [[RCCoreDataManager sharedInstance] getRemoteControlCount]; i++) { count++; //初始化所有的遥控器页面 RCButtonBoardView* btnBoard = [[RCButtonBoardView alloc] initWithFrame:CGRectMake(320.0f*i, 30.0f, self.view.frame.size.width,self.view.frame.size.height - 30.0f)]; [self.allButtonBoards setObject:btnBoard forKey:[NSNumber numberWithInt:i]];

// [self.allButtonBoards setObject:btnBoard forKey:[NSValue valueWithBytes:&i objCType:@encode(int)]]; // [self.allButtonBoards setObject:btnBoard forKey:[NSString stringWithFormat:@"rc%d",i]];

[_container addSubview:btnBoard]; }