UITextField 对打开 UIPickerView 无响应

Question

所以我使用 UIPickerView 作为 UITextField 的第一响应者。我将其设置为显示：

var myPickerView = UIPickerView()
myTextField.inputView = myPickerView

在我向视图添加 UITapGestureRecognizer（这将允许我在选择器视图之外单击以将其关闭）之前，我没有遇到此问题，如下所示：

let dismissUnitPickerGesture = UITapGestureRecognizer(target: self, action: "hidePicker")
dismissUnitPickerGesture.delegate = self
dismissUnitPickerGesture.cancelsTouchesInView = false

hidePicker 函数：

@IBAction func hidePicker(){
    myTextField.resignFirstResponder()

    //I don't think this code is relevant to the problem, but I included it just in case
    if materialSelectedOption == "Aluminum Cans" {
        amountTextField.placeholder = "Number of Cans"
        unitCell.hidden = true
    }
}

现在最多需要在模拟器上的 UITextField 上单击五次才能打开选择器视图，这很令人沮丧，而且显然对应用程序不利。我很确定这与点击手势有关，但我可能是错的。

如果你们还有其他问题，请告诉我。

Answer 1

添加UITapGestureRecognizer 只是为了检测到在pickerView 之外注册了一个点击并隐藏它是错误的！ 您可以使用touchesBegan 函数并像这样调用self.view.endEditing(true)：

    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
        self.view.endEditing(true)
        //or use textField.endEditing(true)
    }

Answer 2

我建议您添加带有“完成”和“清除”项目的工具栏，而不是手势。 您可以使用以下代码：

    func textFieldDidBeginEditing(sender: UITextField) {{
        let toolBar = UIToolbar(frame: CGRectMake(0, self.myTextField.frame.size.height/6, self.myTextField.frame.size.width, 40.0))
        toolBar.layer.position = CGPoint(x: self.myTextField.frame.size.width/2, y: self.myTextField.frame.size.height-20.0) 
        toolBar.barStyle = UIBarStyle.BlackTranslucent       
        toolBar.tintColor = UIColor.whiteColor()


        let defaultButton = UIBarButtonItem(title: "Clear", style: UIBarButtonItemStyle.Plain, target: self, action: #selector(CustomTimePickerTextView.clearTime(_:)))   
        let doneButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.Done, target: self, action: #selector(CustomTimePickerTextView.donePressed(_:)))    
        let flexSpace = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.FlexibleSpace, target: self, action: nil)
        let textButton = UIBarButtonItem(title: self.placeholder, style: UIBarButtonItemStyle.Plain, target: nil, action: nil)

        toolBar.setItems([defaultButton,flexSpace,textButton,flexSpace,doneButton], animated: true)

        self.myTextField.inputAccessoryView = toolBar
    }

    func clearTime(sender:UIBarButtonItem) {
        //
    }

    func donePressed(sender: UIBarButtonItem) {
        self.myTextField.resignFirstResponder()

    }