将Int转换为CGFloat会产生0.000000 [英] Converting Int to CGFloat results in 0.000000

问题描述

我正在尝试从数组中获取 Int 值并将它们转换为 CGFloat s以便我可以创建来自红色，绿色和蓝色值的 UIColor 。很简单吧？

I am attempting to take Int values from an Array and convert them into CGFloats so that I may create a UIColor from those red, green, and blue values. Simple enough, right?

我可以成功地从数组中获取 Int 值，但是当我尝试转换为<$ c时$ c> CGFloat ，结果为0.000000。这是为什么？

I can successfully get the Int values out of the array, but when I attempt to convert to CGFloat, the result is 0.000000. Why is this?

let colorArray = NSUserDefaults.standardUserDefaults().arrayForKey("colors")
let redValue = colorArray[0] as Int
let greenValue = colorArray[1] as Int
let blueValue = colorArray[2] as Int
NSLog("%i", redValue) //prints 255
NSLog("%i", greenValue) //prints 250
NSLog("%i", blueValue) //prints 150
let redFloat = CGFloat(redValue) / 255.0
let greenFloat = CGFloat(greenValue) / 255.0
let blueFloat = CGFloat(blueValue) / 255.0
NSLog("%f", redFloat) //prints 0.000000
let color = UIColor(red: redFloat, green: greenFloat, blue: blueFloat, alpha: 1)

如果我不除以255.0我得到了相同的结果 - 0.我在这里做错了什么？

If I don't divide by 255.0 I get the same result - 0. What am I doing wrong here?

推荐答案

这似乎是基金会的一个奇怪问题字符串格式和从 CGFloat 转换。 NSString（格式：_：）也会出现同样的问题。如果您使用 NSLog（％f，redFloat.native）或 print（\（redFloat））或只是 print（redFloat）没有问题。

This seems to be a weird problem with Foundation string formatting and conversion from CGFloat. The same problem occurs with NSString(format:_:). If you use NSLog("%f", redFloat.native) or print("\(redFloat)") or just print(redFloat) there are no problems.

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