http://www.cnblogs.com/YouXianMing/p/3793913.html
layer 不能自动autolay， 只能在viewDidLayout里面设置宽度
- (void) viewDidLayoutSubviews {
[super viewDidLayoutSubviews]; //if you want superclass's behaviour...
// resize your layers based on the view's new frame
self.editViewBorderLayer.frame = self.editView.bounds;
}
gradientLayer = [CAGradientLayer layer];
_gradientLayer.frame = maskedImageView.bounds;
_gradientLayer.colors = colors; //set locations for the colors
NSArray * startingLocations = @[@0.0, @0.4,@1.0];
NSArray *endinglocations = @[@0.0,@0.8,@1.0]; // Update the model layer to the final point
_gradientLayer.locations = endinglocations;
_gradientLayer.startPoint = CGPointMake(0.0f, 0.3f);
_gradientLayer.endPoint = CGPointMake(1.0f, 0.5f); //add the text image as a mask on the gradient layer
_gradientLayer.mask = maskedImageView.layer; //add the gradient layer to the holder view
[_slideImageView.layer addSublayer:_gradientLayer];
location 代表的是分界线， 比如三个的话就为 @[@(0), @(5), @(1)]
https://github.com/yannickl/DynamicColor
down vote
accepted
- (UIColor *)lighterColorForColor:(UIColor *)c
{
CGFloat r, g, b, a;
if ([c getRed:&r green:&g blue:&b alpha:&a])
return [UIColor colorWithRed:MIN(r + 0.2, 1.0)
green:MIN(g + 0.2, 1.0)
blue:MIN(b + 0.2, 1.0)
alpha:a];
return nil;
} - (UIColor *)darkerColorForColor:(UIColor *)c
{
CGFloat r, g, b, a;
if ([c getRed:&r green:&g blue:&b alpha:&a])
return [UIColor colorWithRed:MAX(r - 0.2, 0.0)
green:MAX(g - 0.2, 0.0)
blue:MAX(b - 0.2, 0.0)
alpha:a];
return nil;
}
http://*.com/questions/11598043/get-slightly-lighter-and-darker-color-from-uicolor @implementation UIColor (LightAndDark) - (UIColor *)lighterColor
{
CGFloat h, s, b, a;
if ([self getHue:&h saturation:&s brightness:&b alpha:&a])
return [UIColor colorWithHue:h
saturation:s
brightness:MIN(b * 1.3, 1.0)
alpha:a];
return nil;
} - (UIColor *)darkerColor
{
CGFloat h, s, b, a;
if ([self getHue:&h saturation:&s brightness:&b alpha:&a])
return [UIColor colorWithHue:h
saturation:s
brightness:b * 0.75
alpha:a];
return nil;
}
@end
CGFloat red, green, blue, alpha;
//Create a sample color
UIColor *redColor = [UIColor redColor];
//Call
[redColor getRed: &red
green: &green
blue: &blue
alpha: &alpha];
NSLog(@"red = %f. Green = %f. Blue = %f. Alpha = %f",
red,
green,
blue,