How to change the change cancel and ok buttons' color in the picker?

问题

I'm using a custompicker in my app and I need to change the cancel and ok buttons' color. I recently changed the whole theme of timepicker and datepicker for android by adding this code to the style file:

 <item name="android:datePickerDialogTheme">@style/AppCompatDialogStyle</item>
    <item name="android:timePickerDialogTheme">@style/TimePickerTheme</item>

item name="colorAccent">#039BE5</item>
    <item name="android:layout_width">wrap_content</item>
    <item name="android:layout_height">wrap_content</item>
  </style>
  <style name="TimePickerTheme" parent="Theme.AppCompat.Light.Dialog">
    <item name="colorAccent">#039BE5</item>
    <item name="android:layout_width">wrap_content</item>
    <item name="android:layout_height">wrap_content</item>
  </style>

Is that a similar code that I can add for the picker?

回答1:

if you change the theme <item name="colorAccent">#039BE5</item> may affect the theme of other controls,you could only change the color in your CustomRenderer like this:

public class CustomPickerRenderer : PickerRenderer
{
    private Context context;
    private IElementController ElementController => Element as IElementController;
    private AlertDialog _dialog;

    public CustomPickerRenderer(Context context) : base(context)
    {
        this.context = context;
    }

    protected override void OnElementChanged(ElementChangedEventArgs<Picker> e)
    {
        base.OnElementChanged(e);
        if (Control == null || e.NewElement == null) return;
        Control.Click += Control_Click1;
    }
    protected override void Dispose(bool disposing)
    {
        Control.Click -= Control_Click1;
        base.Dispose(disposing);
    }

    private void Control_Click1(object sender, EventArgs e)
    {
        Picker model = Element;

        var picker = new NumberPicker(Context);
        if (model.Items != null && model.Items.Any())
        {
            picker.MaxValue = model.Items.Count - 1;
            picker.MinValue = 0;
            picker.SetDisplayedValues(model.Items.ToArray());
            picker.WrapSelectorWheel = false;
            picker.DescendantFocusability = DescendantFocusability.BlockDescendants;
            picker.Value = model.SelectedIndex;
        }

        var layout = new LinearLayout(Context) { Orientation = Orientation.Vertical };
        layout.AddView(picker);

        ElementController.SetValueFromRenderer(VisualElement.IsFocusedProperty, true);

        var builder = new AlertDialog.Builder(Context);
        builder.SetView(layout);
        builder.SetTitle(model.Title ?? "");

        //change the text or color here
        builder.SetNegativeButton(Html.FromHtml("<font color='#039BE5'>Cancel</font>"), (s, a) =>
        {
            ElementController.SetValueFromRenderer(VisualElement.IsFocusedProperty, false);
            // It is possible for the Content of the Page to be changed when Focus is changed.
            // In this case, we'll lose our Control.
            Control?.ClearFocus();
            _dialog = null;
        });

         //change the text or color here
        builder.SetPositiveButton(Html.FromHtml("<font color='#039BE5'>OK</font>"), (s, a) =>
        {
            ElementController.SetValueFromRenderer(Picker.SelectedIndexProperty, picker.Value);
            // It is possible for the Content of the Page to be changed on SelectedIndexChanged.
            // In this case, the Element & Control will no longer exist.
            if (Element != null)
            {
                if (model.Items.Count > 0 && Element.SelectedIndex >= 0)
                    Control.Text = model.Items[Element.SelectedIndex];
                ElementController.SetValueFromRenderer(VisualElement.IsFocusedProperty, false);
                // It is also possible for the Content of the Page to be changed when Focus is changed.
                // In this case, we'll lose our Control.
                Control?.ClearFocus();
            }
            _dialog = null;
        });

        _dialog = builder.Create();
        _dialog.DismissEvent += (ssender, args) =>
        {
            ElementController?.SetValueFromRenderer(VisualElement.IsFocusedProperty, false);
        };
        _dialog.Show();
    }
}

update i test it on Tablet emulator,it works well

来源：https://stackoverflow.com/questions/56391601/how-to-change-the-change-cancel-and-ok-buttons-color-in-the-picker