UITextView拒绝更改其颜色

Question

in some cases things you'd expect to solve within a sec turn out to become a lifetime adventure. This is one of these cases :)

All I wanted to do, is simply change the text color of one of my UITextViews. So far I tried:

UIColor *myColor = [UIColor colorWithHue:38 saturation:98 brightness:100 alpha:1.0];
[myTextView setTextColor:myColor];

OR

UIColor *myColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"colorImage.png"]];
[myTextView setTextColor:myColor]; 

Both seem to work fine for UILabels, but fail for UITextView elements. When I try [UIColor colorWithHue... I only get a reddish kinda color, no matter what values I choose (except values for black and white. They work). The colorWithPatternImage does not change textColor at all.

Strange isn't it? I obviously must be missing something. Help is very much appreciated. Thanks in advance.

Answer 1

像其他UIColor方法一样， +colorWithHue:saturation:brightness:alpha:取值范围是0到1，而不是0到100。我不希望+colorWithPatternImage:可以完全用于文本渲染，除非您想自己制作基于核心图形的绘图代码。

Answer 2

As Noah said, values are expected to be in the range [0, 1]. Try this instead and modify as necessary:

UIColor *myColor = [UIColor colorWithHue:0.38 saturation:0.98 brightness:1.0 alpha:1.0];
[myTextView setTextColor:myColor];

Answer 3

If you are used to your graphics program's color numbers, and want to sacrifice a little efficiency for readability, you can do the conversion in the assignment statements like colorWithHue:(112/360.0) below:

    UIColor *color1 = [UIColor colorWithHue:(112/360.0) saturation:.63 brightness:.73 alpha:1];//green
    UIColor *color2 = [UIColor colorWithHue:(70/360.0) saturation:.79 brightness:.84 alpha:1];//lime
    UIColor *color3 = [UIColor  colorWithHue:(49/360.0) saturation:.77 brightness:.91 alpha:1];//yellow

You can express the Hue numbers as fractions to translate from Fireworks Hue, Saturation, Brightness numbers to UIColor's 0-1 scale. It's especially helpful on the Hue, for which Fireworks uses a 360 degree scale. The saturation, brightness, and alpha are divided by 100 in Fireworks, so the conversion is simple. In development, the Hue fraction bridges the way my graphics program presents color HSB, and what Objective-C requires. The numbers can be tweaked easily. For the release version, I could substitute .54 for color1's 112/360.

Answer 4

Ok, I managed to get it to work. Thanks for all your help.

In case somebody runs into problems with the hue value, which is in degrees. Devide it by 360 before you use it in XCode.