Question

我以编程方式编写了以下UIPickerView，以提取从JSON获取的值。

基本上，在选择customerTextField时，应该会看到UIPickerView出现，其中包含来自正在解析的链接的值。

相反，我只是看到一个键盘出现。

是否存在语法问题，我没有收到任何错误，UIPickerView根本没有显示。

    import UIKit

class CreateRMA_ViewController: UIViewController, UIPickerViewDataSource, UIPickerViewDelegate, UITextFieldDelegate {



        @IBOutlet weak var customerTextField: UITextField!


    var pickerView: UIPickerView!
    var values: [AnyObject] = []

    func numberOfComponents(in pickerView: UIPickerView) -> Int {
        return 1
    }

    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {

        return self.values.count

    }

    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {


        let titleRow = (values[row] as? String)!
        return titleRow


    }

    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {


        if values.count > 0 && values.count >= row{
            self.customerTextField.text = self.values[row] as? String
            self.pickerView.isHidden = true
        }

    }




    func textFieldDidBeginEditing(_ textField: UITextField) {
        //when you select the text field the picker view will be visible

        if(textField == self.customerTextField){
            self.pickerView.isHidden = false
            self.view.endEditing(true)
        }

    }



    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()

    }


        override func viewDidLoad() {
            super.viewDidLoad()

            pickerView = UIPickerView()
            pickerView.dataSource = self
            pickerView.delegate = self


            //get the values from sql/Json
            let url = NSURL(string: "https://www.example.com/test/test.php")

            let data = NSData(contentsOf: url! as URL)
            var tmpValues = try! JSONSerialization.jsonObject(with: data! as Data, options: JSONSerialization.ReadingOptions.mutableContainers) as! NSArray
            tmpValues = tmpValues.reversed() as NSArray
            reloadInputViews()


            for candidate in tmpValues {
                if let cdict = candidate as? NSDictionary {

                    //fullName is the column name in sql/json
                    let names = cdict["customer"]
                    self.values.append(names! as AnyObject)


                }
            }
    }

}

Answer 1

在ViewDidLoad()中，您创建了pickerView，将delegate和dataSource设置为self，很好。但是您尚未完成的工作，还没有将pickerView添加为UITextfield的{{1}}。这就是为什么您没有获取pickerView

的原因

这样做

inputView

您还需要做其他事情，在override func viewDidLoad() { // do your works pickerView = UIPickerView() pickerView.dataSource = self pickerView.delegate = self customerTextField.inputView = pickerView }中删除与UIPickerView相关的代码块。

Answer 2

您必须将文本字段的inputView设置为pickerView

override func viewDidLoad() {
        super.viewDidLoad()

        pickerView = UIPickerView()
        pickerView.dataSource = self
        pickerView.delegate = self

       customerTextField.inputView = pickerView

  }

选择TextField时未显示UIPickerView

2 个答案: