objective-c 使用 RGB 值创建 NSColor
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Creating a NSColor with RGB value
提问by nanochrome
How do I create a NSColor from a RGB value?
如何从 RGB 值创建 NSColor？
回答by Matt Ball
回答by MiMo
Also don't forget to do the following conversion from the actual RGB values you get, lets say from Photoshop...
也不要忘记从您获得的实际 RGB 值进行以下转换，例如从 Photoshop...
an RGB of (226, 226, 226) could be instantiated as a NSColor using the values:
可以使用以下值将 (226, 226, 226) 的 RGB 实例化为 NSColor：
Red: 226/255 = 0.886...
Green: 226/255 = 0.886...
Blue: 226/255 = 0.886...
[NSColor colorWithDeviceRed:0.886f green:0.886f blue:0.886f alpha:1.0f];
Why 255? 8-bit color channels range from 0 to 255 (inclusive). When normalized this is scaled to the range [0,1] (inclusive). See references for conversions from normalized values to unnormalized values and vice versa.
为什么是255？8 位颜色通道的范围从 0 到 255（含）。归一化后，它会缩放到范围 [0,1]（含）。请参阅有关从规范化值到非规范化值的转换的参考资料，反之亦然。
References
参考
- OpenGL ES Full Specification, See Table 2.7 on Page 38
- Unreal Engine Color Conversion
- OpenGL ES 完整规范，请参阅第 38 页上的表 2.7
- 虚幻引擎颜色转换
回答by nash
float red = 0.5f;
float green = 0.2f;
float blue = 0.4f;
float alpha = 0.8f;
NSColor *rgb = [NSColor colorWithDeviceRed:red green:green blue:blue alpha:alpha];
回答by emreoktem
Extension for Swift 2
Swift 2 的扩展
extension NSObject {
func RGB(r:CGFloat, g:CGFloat, b:CGFloat, alpha:CGFloat? = 1) -> NSColor {
return NSColor(red: r/255, green: g/255, blue: b/255, alpha: alpha!)
}
}
Then just call
然后就打电话
RGB(r: 16, g: 105, b: 125)
or
或者
RGB(r: 16, g: 105, b: 125, alpha: 0.5)
