UIPickerView selectRow doesn't works

问题

I try to select a row in my PickerView but it doesn't works. It stays at the first row.

Here is my code:

@IBOutlet weak var pickerView: UIDatePicker!

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

func pickerView(pickerView: UIPickerView!, numberOfRowsInComponent component: Int) -> Int
{
    return 10
}

func pickerView(pickerView: UIPickerView!, titleForRow row: Int, forComponent component: Int) -> String!{
    return String(row + 1)
}


//In viewDidLoad
pickerView.selectRow(6, inComponent: 0, animated: true)

The pickerView is working well it shows 1 to 10 but the selectRow doesn't works.

It should select the sixth row but it stays on the first one.

回答1:

While inside the viewDidLoad method, your picker is empty. Since there is no 6th element to pick, it doesn't pick it.

You can do this if you delay execution of the select call until after the data is finished loading. Likely one cycle will be enough.

First though, try moving your select to viewDidAppear.

Good luck!

来源：https://stackoverflow.com/questions/27180995/uipickerview-selectrow-doesnt-works