渐变的颜色

    UIColor *topColor = [UIColor redColor];
    UIColor *bottomColor = [UIColor yellowColor];
    
    NSArray *gradientColors = [NSArray arrayWithObjects:(id)topColor.CGColor, (id)bottomColor.CGColor, nil];
    NSArray *gradientLocations = [NSArray arrayWithObjects:[NSNumber numberWithInt:0.0],[NSNumber numberWithInt:1.0], nil];
    
    CAGradientLayer *gradientLayer = [CAGradientLayer layer];
    gradientLayer.colors = gradientColors;
    gradientLayer.locations = gradientLocations;
    
    CAGradientLayer *backgroundLayer = gradientLayer;
    backgroundLayer.frame = CGRectMake(0, 0, CGRectGetWidth(dayView.bounds), CGRectGetHeight(dayView.bounds));
    [dayView.layer insertSublayer:backgroundLayer atIndex:0];

1  dayView.backgroundColor = [UIColor colorWithGradientStyle:UIGradientStyleTopToBottom withFrame: CGRectMake(0, 0, CGRectGetWidth(dayView.bounds)*1.5, CGRectGetHeight(dayView.bounds)) andColors:@[[UIColor redColor], [UIColor yellowColor] ]];