Question

我正在尝试使用输入发出警告消息，然后从输入中获取值。我发现了很多很好的教程如何制作输入文本字段。但我无法从警报中获得价值。

Answer 1

针对Swift 3及更高版本进行了更新：

//1. Create the alert controller.
let alert = UIAlertController(title: "Some Title", message: "Enter a text", preferredStyle: .alert)

//2. Add the text field. You can configure it however you need.
alert.addTextField { (textField) in
    textField.text = "Some default text"
}

// 3. Grab the value from the text field, and print it when the user clicks OK.
alert.addAction(UIAlertAction(title: "OK", style: .default, handler: { [weak alert] (_) in
    let textField = alert.textFields![0] // Force unwrapping because we know it exists.
    print("Text field: \(textField.text)")
}))

// 4. Present the alert.
self.present(alert, animated: true, completion: nil)

Swift 2.x

假设您想要iOS上的操作提醒：

//1. Create the alert controller.            
var alert = UIAlertController(title: "Some Title", message: "Enter a text", preferredStyle: .Alert)

//2. Add the text field. You can configure it however you need.
alert.addTextFieldWithConfigurationHandler({ (textField) -> Void in
    textField.text = "Some default text."
})

//3. Grab the value from the text field, and print it when the user clicks OK. 
alert.addAction(UIAlertAction(title: "OK", style: .Default, handler: { [weak alert] (action) -> Void in
    let textField = alert.textFields![0] as UITextField
    println("Text field: \(textField.text)")
}))

// 4. Present the alert.
self.presentViewController(alert, animated: true, completion: nil)

Answer 2

Swift 3/4

您可以使用以下扩展名方便。

results <- map2(dat1, dat2, ~ { pl.val <- .y[1] vg.val <- .y[2] re.val <- .y[3] me.val <- .y[4] rain1 <- if(is.na(pl.val) | is.na(vg.val)) NA else sum(.x[pl.val:vg.val], na.rm = T) rain2 <- if(is.na(vg.val) | is.na(re.val)) NA else sum(.x[(vg.val+ 1):re.val], na.rm = T) rain3 <- if(is.na(re.val) | is.na(me.val)) NA else sum(.x[(re.val + 1):me.val], na.rm = T) c(rain1 = rain1, rain2 = rain2, rain3 = rain3) } ) # If you want data.frame instead of list invoke("rbind", results)内的用法：

ViewController

扩展代码：

showInputDialog(title: "Add number",
                subtitle: "Please enter the new number below.",
                actionTitle: "Add",
                cancelTitle: "Cancel",
                inputPlaceholder: "New number",
                inputKeyboardType: .numberPad)
{ (input:String?) in
    print("The new number is \(input ?? "")")
}

Answer 3

迅速4 ans Xcode 10

使用“保存”和“取消”操作添加两个文本字段，并读取TextFields文本数据

func alertWithTF() {
    //Step : 1
    let alert = UIAlertController(title: "Great Title", message: "Please input something", preferredStyle: UIAlertControllerStyle.alert)
    //Step : 2
    let save = UIAlertAction(title: "Save", style: .default) { (alertAction) in
        let textField = alert.textFields![0] as UITextField
        let textField2 = alert.textFields![1] as UITextField
        if textField.text != "" {
            //Read TextFields text data
            print(textField.text!)
            print("TF 1 : \(textField.text!)")
        } else {
            print("TF 1 is Empty...")
        }

        if textField2.text != "" {
            print(textField2.text!)
            print("TF 2 : \(textField2.text!)")
        } else {
            print("TF 2 is Empty...")
        }
    }

    //Step : 3
    //For first TF
    alert.addTextField { (textField) in
        textField.placeholder = "Enter your first name"
        textField.textColor = .red
    }
    //For second TF
    alert.addTextField { (textField) in
        textField.placeholder = "Enter your last name"
        textField.textColor = .blue
    }

    //Step : 4
    alert.addAction(save)
    //Cancel action
    let cancel = UIAlertAction(title: "Cancel", style: .default) { (alertAction) in }
    alert.addAction(cancel)
    //OR single line action
    //alert.addAction(UIAlertAction(title: "Cancel", style: .default) { (alertAction) in })

    self.present(alert, animated:true, completion: nil)

}

有关更多说明，https://medium.com/@chan.henryk/alert-controller-with-text-field-in-swift-3-bda7ac06026c

在Swift的iOS警报中从TextField获取输入值

3 个答案: