iphone - 如何在iOS中实现c++ setRGB

Question

我有很大的 int 值RGB = 4294967295; 如何从这个值设置颜色？在 c++ 中，我可以使用setRGB()方法。我怎样才能在iOS中制作它？

Answer 1

您可以像这样使用按位运算符：

float alpha = (intARGB >> 24) % 256;
float red = (intARGB >> 16) % 256;
float green = (intARGB >> 8) % 256;
float blue = intARGB % 256;
UIColor *theColor = [UIColor colorWithRed:red/255. green:green/255. blue:blue/255. alpha:alpha/255.];

Answer 2

但更好用

unsigned char alpha = (color >> 24) & 0xff;
unsigned char red = (color >> 16) & 0xff;
unsigned char green = (color  >> 8) &0xff;
unsigned char blue = color &0xff;
UIColor *theColor = [UIColor colorWithRed:red green:green blue:blue alpha:alpha];