如何檢查TextView是否爲空？

Question

我已經使用此代碼來檢查Textview是否爲空。它能正常工作，如果我給空間，但如果我按「Enter」按鈕，它允許我輸入數據庫中的數據。這有什麼問題？

func validation()->Int 
{ 
    var i = 1 

    //1st way 

    if txt_view.text.isEmpty 
    { 
     var alert = UIAlertView() 
     alert.title = "Message" 
     alert.message = "Write Career Objective" 
     alert.addButtonWithTitle("OK") 
     alert.show() 
     i = 0 
    } 

    //2nd way 

    if txt_view.text.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet()) == "" 
    { 
     var alert = UIAlertView() 
     alert.title = "Message" 
     alert.message = "Write Career Objective" 
     alert.addButtonWithTitle("OK") 
     alert.show() 
     i = 0 
    } 

    return i 
} 

Answer 1

更改你的第二次嘗試，包括新線：

if txt_view.text.stringByTrimmingCharactersInSet(
    NSCharacterSet.whitespaceAndNewlineCharacterSet()).isEmpty 
{ 
    var alert = UIAlertView() 
    alert.title = "Message" 
    alert.message = "Write Career Objective" 
    alert.addButtonWithTitle("OK") 
    alert.show() 
    i = 0 
} 

而且我總是喜歡在isEmpty比較空字符串== ""。