选择器视图默认行未使用 swift 2 更改

Question

我想通过从核心数据中读取数据并检查它们，以编程方式更改选择器视图默认 selected 行。我使用了 select 行并做了 select 行，但实际上它只是改变了选择器视图的值，而不是它的视觉 selected 行！这令人困惑。

我的意思是在这部分：

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

        labelPassedData.text = languagePicker[row]
}

这部分：

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

func pickerView(pickerView : UIPickerView , numberOfRowsInComponent component : Int) ->Int{
    return languagePicker.count
}

func pickerView(pickerView : UIPickerView, titleForRow row:Int, forComponent component : Int) -> String?
{
    return languagePicker[row]
}

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

    labelPassedData.text = languagePicker[row]

    self.Insert(labelPassedData!.text!) // calling save lang function


    let Language = languageDB[0]
    dbshow!.text = Language.valueForKey("lang") as? String

    self.view.endEditing(true)
}

我从核心数据中获取了值，但可视化选择器视图没有变化！

这是我的代码：

更新代码

override func viewDidAppear(animated: Bool) {

fetch("Language")
let Language = languageDB[0]
let row_value : String = Language.valueForKey("lang") as! String

let row_num : Int

if(row_value == "فارسی"){

    row_num = 0
    self.pickerView.selectRow(row_num, inComponent: 0, animated: true)
    self.pickerView(self.pickerView, didSelectRow: row_num, inComponent: 0)

}else if(row_value == "English"){

    row_num = 1
    self.pickerView.selectRow(row_num, inComponent: 0, animated: true)
    self.pickerView(self.pickerView, didSelectRow: row_num, inComponent: 0)

}else if(row_value == "العربية"){

    row_num = 2
    self.pickerView.selectRow(row_num, inComponent: 0, animated: true)
    self.pickerView(self.pickerView, didSelectRow: row_num, inComponent: 0)
}

self.pickerView.reloadComponent(0)

}

Answer 1

我解决了这个问题，它与声明选择器视图数据源和委托有关这部分解决了我的问题：

override func viewDidLoad() {
    super.viewDidLoad()

    self.pickerView.dataSource = self
    self.pickerView.delegate = self
}

选择器视图默认行未使用 swift 2 更改

Picker view default row is not changing using swift 2

select

core-data

uipickerview

ios

swift2

更新代码