将颜色定义为CGFloat

Question

我正在用以下代码创建一个渐变，我在另一篇关于在iOS 中绘制径向渐变的stackoverflow文章中找到了这些代码

- (void)drawInContext:(CGContextRef)ctx
{ 
    if ([[[NSUserDefaults standardUserDefaults] objectForKey:@"theme"] isEqualToString:@"black"]) {
    }
    size_t gradLocationsNum = 2;
    CGFloat gradLocations[2] = {0.0f, 1.0f};
    CGFloat gradColors[8] = {156/255.0f, 97/255.0f, 249/255.0f,1.0f,41/255.0f,131/255.0f,242/255.0f,1.0f};
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGGradientRef gradient = CGGradientCreateWithColorComponents(colorSpace, gradColors, gradLocations, gradLocationsNum);
    CGColorSpaceRelease(colorSpace);
    CGPoint gradCenter= CGPointMake(self.bounds.size.width/2, self.bounds.size.height+100);
    float gradRadius = MAX(self.bounds.size.width , self.bounds.size.height) ;
    CGContextDrawRadialGradient(ctx, gradient, gradCenter, 0, gradCenter, gradRadius, kCGGradientDrawsAfterEndLocation);

    CGGradientRelease(gradient);
}

我不知道如何定义CGFloat gradColors[8] = {156/255.0f, 97/255.0f, 249/255.0f,1.0f,41/255.0f,131/255.0f,242/255.0f,1.0f};，这样我就可以做一些类似的事情：

CGFloat gradColors[8];
if ...
    gradColors[8] = {156/255.0f, 97/255.0f, 249/255.0f,1.0f,41/255.0f,131/255.0f,242/255.0f,1.0f};
else if ...
    gradColors[8] = {156/255.0f, 97/255.0f, 249/255.0f,1.0f,41/255.0f,131/255.0f,242/255.0f,1.0f};

还有：有办法将UIColor转换成这种格式吗？

Answer 1

您可以尝试使用接受CGColor数组的CGGradientCreateWithColors()。

例如。

CGGradientRef gradient = CGGradientCreateWithColors(colorSpace, (__bridge CFArrayRef)@[(id)aUIColor1.CGColor, (id)aUIColor2.CGColor], gradientLocations);