How to change selected item when user click on done not scroll - xamarin

Question

i have issue with picker Update Mode
after search find this line
"iOSSpecific:Picker.UpdateMode="WhenFinished""
after add to my custom picker selected item not changed
protected override void OnElementChanged(ElementChangedEventArgs<Picker> e)
{
base.OnElementChanged(e);
var extendedPicker = e.NewElement as CustomPicker;
if (extendedPicker == null) return;
var toolbar = new UIToolbar(new CGRect(0.0f, 0.0f, Control.Frame.Size.Width, 44.0f));
toolbar.Items = new[]
{
new UIBarButtonItem(UIBarButtonSystemItem.FlexibleSpace),
new UIBarButtonItem("Yes",
UIBarButtonItemStyle.Done,
delegate {
Control.ResignFirstResponder();
})
};
if (this.Control != null)
{
Control.InputAccessoryView = toolbar;
}
}

Answer 1

When setting a new UIToolbar for Control.InputAccessoryView , need to set selected value for Control manually .
Have a try with follow code in renderer :
public class CustomPickerRenderer : PickerRenderer, IUIPickerViewDelegate, IUIPickerViewDataSource
{
string SelectedValue;
protected override void OnElementChanged(ElementChangedEventArgs<Picker> e)
{
base.OnElementChanged(e);
SelectedValue = Element.Items[0];
UIPickerView pickerView = (UIPickerView)Control.InputView;
pickerView.WeakDelegate = this;
pickerView.DataSource = this;
pickerView.Delegate = new deleagteClass();
var toolbar = new UIToolbar(new CGRect(0.0f, 0.0f, Control.Frame.Size.Width, 44.0f));
toolbar.Items = new[]
{
new UIBarButtonItem(UIBarButtonSystemItem.FlexibleSpace),
new UIBarButtonItem("Yes",
UIBarButtonItemStyle.Done,
delegate {
Control.ResignFirstResponder();
Control.Text = SelectedValue;
})
};
if (this.Control != null)
{
Control.InputAccessoryView = toolbar;
}
}
public nint GetComponentCount(UIPickerView pickerView)
{
return 1;
}
public nint GetRowsInComponent(UIPickerView pickerView, nint component)
{
return Element.Items.Count;
}
[Export("pickerView:viewForRow:forComponent:reusingView:")]
public UIView GetView(UIPickerView pickerView, nint row, nint component, UIView view)
{
UILabel label = new UILabel
{
TextColor = UIColor.Black,
Text = Element.Items[(int)row].ToString(),
TextAlignment = UITextAlignment.Center,
};
var picker = this.Element;
return label;
}
[Export("pickerView:didSelectRow:inComponent:")]
public void Selected(UIPickerView pickerView, nint row, nint component)
{
SelectedValue = Element.Items[(int)row];
}
}
The effect :