How to set iOS UITextField placeholder color? (RubyMotion + iOS)

问题

How to use RubyMotion to set a textField's placeholder text foreground color?

Example code:

textField = UITextField.alloc.init
textField.placeholder = "Hello World"

The placeholder text shows up gray; I want it to be red.

This is using RubyMotion, not Objective-C.

回答1:

Use an attributed string like this:

self.attributedPlaceholder = 
  NSAttributedString.alloc.initWithString(
    self.placeholder || "Hello World",  
    attributes: {NSForegroundColorAttributeName => UIColor.redColor}
  )

This works on iOS7, and likely on iOS6, and not on earlier iOS versions.

Careful: be certain to use the hash syntax key => val instead of key: val.

来源：https://stackoverflow.com/questions/25236456/how-to-set-ios-uitextfield-placeholder-color-rubymotion-ios