Get control's dimensions in CustomRenderer (Xamarin.Forms iOS)

Question

I've overridden OnElementChanged method inside a custom EntryRenderer which looks like this:

protected override void OnElementChanged(ElementChangedEventArgs<Entry> e)
{
    base.OnElementChanged(e);

    if (Control != null)
    {
        var iconLabel = new UILabel();
        iconLabel.Font = FontAwesome.Font(12);
        iconLabel.Text = " " + FontAwesome.FAPlay;
        iconLabel.Frame = new CGRect(x: 5, y: 0, width: 20, height: 20);
        Control.LeftView = iconLabel;
        Control.LeftViewMode = UITextFieldViewMode.Always;

        Control.BorderStyle = UITextBorderStyle.None;
        var bottomLine = new CALayer();
        bottomLine.Frame = new CGRect(0.0, Control.Frame.Height - 1, Control.Frame.Width, 1.0);
        bottomLine.BackgroundColor = UIColor.White.CGColor;
        Control.Layer.AddSublayer(bottomLine);
    }
}

All I want to do is customize Entry control to add FontAwesome icon on the left and add a layer at the bottom to make it look like it only has bottom-border.

The problem is that Control.Frame doesn't have Width & Height (their value is 0).

Any help or another way to hack border bottom Entry (UITextField) style? Thanks in advance.

Maybe you could also check if the e.NewElement (which is the Xamarin Entry) isn't null and apply those dimensions? — Gerald Versluis

SushiHangover SushiHangover · Accepted Answer · 2016-04-14T11:09:20

All I want to do is customize Entry control to add FontAwesome icon on the left and add a layer at the bottom to make it look like it only has bottom-border.

Use a colored UIView added as Subview of the control and the clipping will be handled for you.

:-)

if (Control != null) {
    Control.BackgroundColor = UIColor.LightGray;
    var iconLabel = new UILabel();
    iconLabel.Font = FontAwesome.Font(12);
    iconLabel.Text = " " + FontAwesome.FAAmbulance;
    iconLabel.Frame = new CGRect(x: 5, y: 0, width: 20, height: 20);
    Control.LeftView = iconLabel;
    Control.LeftViewMode = UITextFieldViewMode.Always;

    Control.BorderStyle = UITextBorderStyle.None;
    Console.WriteLine ("cs: " + customSize);
    UIView myBox = new UIView (new CGRect (0.0, 20.0, 1000.0, 1.0)); 
    myBox.BackgroundColor = UIColor.Red;
    Control.AddSubview(myBox);
}

if (Control != null) {
    var iconLabel = new UILabel();
    iconLabel.Font = FontAwesome.Font(12);
    iconLabel.Text = " " + FontAwesome.FAPlay;
    iconLabel.Frame = new CGRect(x: 5, y: 0, width: 20, height: 20);
    Control.LeftView = iconLabel;
    Control.LeftViewMode = UITextFieldViewMode.Always;

    Control.BorderStyle = UITextBorderStyle.None;
    Console.WriteLine ("cs: " + customSize);
    UIView myBox = new UIView (new CGRect (0.0, 20.0, 1000.0, 1.0)); 
    myBox.BackgroundColor = UIColor.Black;
    Control.AddSubview(myBox);
}

Get control's dimensions in CustomRenderer (Xamarin.Forms iOS)

1 Answers