UI-UIColor-initWithRed:green:blue:alpha:调研

<span style="font-size:18px;">- (UIColor *)initWithRed:(CGFloat)red green:(CGFloat)green blue:(CGFloat)blue alpha:(CGFloat)alpha</span>

初始化并且根据参数(红,
绿, 蓝, 透明度 参数范围 0-1.0 ),返回一个UIColor的对象,

自定义255RGB值,转化成
0 - 1.0;

eg⬇️

<span style="font-size:18px;">/* 浅灰蓝色(下图第一行第三列, R:176 G:224 B:230) */UIColor *color = [[UIColor alloc] initWithRed:176/255.0 green:224/255.0 blue:230/255.0 alpha:0.9];</span>