Ios CAGradientLayer显示为纯色
我试图在视图上设置渐变背景,但下面的代码使UIView显示为纯黑色。如果我将白色更改为绿色,渐变将正确显示。将图层的背景色更改为绿色将使视图显示为纯绿色 我的猜测是,我正在处理某种透明度问题,但我不知道如何解决它Ios CAGradientLayer显示为纯色,ios,core-animation,Ios,Core Animation,我试图在视图上设置渐变背景,但下面的代码使UIView显示为纯黑色。如果我将白色更改为绿色,渐变将正确显示。将图层的背景色更改为绿色将使视图显示为纯绿色 我的猜测是,我正在处理某种透明度问题,但我不知道如何解决它 CAGradientLayer *gradientLayer = [CAGradientLayer layer]; gradientLayer.colors = [NSArray arrayWithObjects:
CAGradientLayer *gradientLayer = [CAGradientLayer layer];
gradientLayer.colors = [NSArray arrayWithObjects:
(id)[[UIColor whiteColor] CGColor],
(id)[[UIColor blackColor] CGColor], nil];
gradientLayer.frame = CGRectMake(0, 0, 1, someView.frame.size.height);
UIGraphicsBeginImageContext(CGSizeMake(1, someView.frame.size.height));
[gradientLayer renderInContext: UIGraphicsGetCurrentContext()];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
someView.backgroundColor = [UIColor colorWithPatternImage: image];
您的白色和黑色在灰度颜色空间中。尝试在RGB颜色空间中制作:
gradientLayer.colors = @[
(id)[UIColor colorWithRed:0 green:0 blue:0 alpha:1].CGColor,
(id)[UIColor colorWithRed:1 green:1 blue:1 alpha:1].CGColor
];
这会解决你的问题,虽然我不确定这背后的石英力学