Ios 如何检查TextView是否为空？

我用这段代码检查Textview是否为空。若我给空间，它可以正常工作，但若我按下“回车”按钮，它允许我在数据库中输入数据。这有什么问题

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
}

---

更改第二次尝试包括新行：

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
}

---

另外，与空字符串相比，我更喜欢

isEmpty

，，

谢谢。。这成功了！！