常用开发技巧系列（六）

+ (UIColor *)colorWithRGBHex:(UInt32)hex
{
	int r = (hex >> 16) & 0xFF;
	int g = (hex >> 8) & 0xFF;
	int b = (hex) & 0xFF;
	
	return [UIColor colorWithRed:r / 255.0f
						   green:g / 255.0f
							blue:b / 255.0f
						   alpha:1.0f];
}

+ (UIColor *)colorWithHexString:(NSString *)stringToConvert{
    
    NSString *cString = [[stringToConvert stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] uppercaseString];
    
    // String should be 6 or 8 characters
    if ([cString length] < 6) {
        return [UIColor clearColor];
    }
    
    // strip 0X if it appears
    if ([cString hasPrefix:@"0X"])
        cString = [cString substringFromIndex:2];
    if ([cString hasPrefix:@"#"])
        cString = [cString substringFromIndex:1];
    if ([cString length] != 6)
        return [UIColor clearColor];

	NSScanner *scanner = [NSScanner scannerWithString:cString];
	unsigned hexNum;
	if (![scanner scanHexInt:&hexNum]) return nil;
	return [UIColor colorWithRGBHex:hexNum];
}

self.backgroundColor = [UIColor colorWithHexString:@"#F1F1F1"];

label.textColor = [UIColor colorWithRGBHex:0x707070];

/// 自定义初始化方法
///
/// - Parameters:
///   - r: red
///   - g: green
///   - b: blue
///   - a: alpha
convenience init(r:UInt32 ,g:UInt32 , b:UInt32 , a:CGFloat = 1.0) {
    self.init(red: CGFloat(r) / 255.0,
              green: CGFloat(g) / 255.0,
              blue: CGFloat(b) / 255.0,
              alpha: a)
}
    
/// 自定义初始化方法
///
/// - Parameters:
///   - hexString: 6位字符 'F1F1F1'
///   - alpha: 透明度值 0.0-1.0
convenience init(hexString: String, alpha:CGFloat = 1.0) {
        
   var r: UInt32 = 0x0
   var g: UInt32 = 0x0
   var b: UInt32 = 0x0
        
   var cString: String = hexString.trimmingCharacters(in: .whitespacesAndNewlines)
   if cString.count < 6 {
        self.init(red: CGFloat(r) / 255.0,
                  green: CGFloat(g) / 255.0,
                  blue: CGFloat(b) / 255.0,
                  alpha: alpha)
        return
    }
        
    let index = cString.index(cString.endIndex, offsetBy: -6)
    let subString = cString[index...]
    if cString.hasPrefix("0X") { cString = String(subString) }
    if cString.hasPrefix("#") { cString = String(subString) }
        
    if cString.count != 6 {
        self.init(red: CGFloat(r) / 255.0,
                  green: CGFloat(g) / 255.0,
                  blue: CGFloat(b) / 255.0,
                  alpha: alpha)
        return
    }
        
    var range: NSRange = NSMakeRange(0, 2)
    let rString = (cString as NSString).substring(with: range)
    range.location = 2
    let gString = (cString as NSString).substring(with: range)
    range.location = 4
    let bString = (cString as NSString).substring(with: range)
        
    Scanner(string: rString).scanHexInt32(&r)
    Scanner(string: gString).scanHexInt32(&g)
    Scanner(string: bString).scanHexInt32(&b)
        
    self.init(red: CGFloat(r) / 255.0,
               green: CGFloat(g) / 255.0,
               blue: CGFloat(b) / 255.0,
               alpha: alpha)
}

self.backgroundColor = UIColor.init(hexString: "F9F9F9")

// 颜色模式
- (CGColorSpaceModel)colorSpaceModel {

	return CGColorSpaceGetModel(CGColorGetColorSpace(self.CGColor));
}


- (NSString *)colorSpaceString {

	switch (self.colorSpaceModel) {

		case kCGColorSpaceModelUnknown:
			return @"kCGColorSpaceModelUnknown";
		case kCGColorSpaceModelMonochrome:
			return @"kCGColorSpaceModelMonochrome";
		case kCGColorSpaceModelRGB:
			return @"kCGColorSpaceModelRGB";
		case kCGColorSpaceModelCMYK:
			return @"kCGColorSpaceModelCMYK";
		case kCGColorSpaceModelLab:
			return @"kCGColorSpaceModelLab";
		case kCGColorSpaceModelDeviceN:
			return @"kCGColorSpaceModelDeviceN";
		case kCGColorSpaceModelIndexed:
			return @"kCGColorSpaceModelIndexed";
		case kCGColorSpaceModelPattern:
			return @"kCGColorSpaceModelPattern";
		default:
			return @"Not a valid color space";
	}
}

// 判断能不能取
- (BOOL)canProvideRGBComponents {
	switch (self.colorSpaceModel) {
		case kCGColorSpaceModelRGB:
		case kCGColorSpaceModelMonochrome:
			return YES;
		default:
			return NO;
	}
}


// 只有单色能取出RGB，要不是就不能
- (NSArray *)arrayFromRGBAComponents {
	NSAssert(self.canProvideRGBComponents, @"Must be an RGB color to use -arrayFromRGBAComponents");

	CGFloat r,g,b,a;
	if (![self red:&r green:&g blue:&b alpha:&a]) return nil;
	
	return  [NSArray arrayWithObjects:
			[NSNumber numberWithFloat:r],
			[NSNumber numberWithFloat:g],
			[NSNumber numberWithFloat:b],
			[NSNumber numberWithFloat:a],
			nil];
}

/// 测试
var timeCount = 0
let  timer =  DispatchSource.makeTimerSource(queue: DispatchQueue.global())
timer.schedule(deadline: .now(), repeating: .seconds(2))
/// 设定时间源的触发事件
timer.setEventHandler(handler: {
               
      timeCount += 1
      if timeCount == 200 {
          timer.cancel()
      }
      print("--------------",timeCount)
      // 返回主线程处理一些事件，更新UI等等
      DispatchQueue.main.async {
         
      }
})
/// 启动时间源
timer.resume()