问题
I'm making a trivia app that prints the question out word by word, and currently it starts at the middle of the UILabel and pushes the previous text upward. I'm trying to find out if I can start the first word at the top left of the label, the continue printing the rest.
func printQuestion ()
{
var str = quizbrain.getQuestionText()
var arr = str.components(separatedBy: " ")
var count = 0
Timer.scheduledTimer(withTimeInterval: 0.25, repeats: true) { (t) in
self.questionLabel.text! += " " + arr[count]
count += 1
if count == arr.count {
t.invalidate()
}
if self.hasBuzzed == true {
t.invalidate()
}
}
回答1:
I'm trying to find out if I can start the first word at the top left of the label
No, you can’t. That’s not how labels draw when their text changes.
Cool workaround: start with the label containing the whole text, but use an attributed string so that the text is the same color as the background (e.g. white on white) and thus invisible. In your timer, change the color of one word at a time to black.
That way, you never change the text, just the color, so the text does not move as each word is revealed.
来源：https://stackoverflow.com/questions/65056860/swift-how-to-get-uilabel-align-to-top-left