protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
// Set the view from the Main.axml layout resource
SetContentView(Resource.Layout.Main);
// Get a reference to the FingerPaintCanvasView from the Main.axml file
fingerPaintCanvasView = FindViewById <FingerPaintCanvasView>(Resource.Id.canvasView);
// Set up the Spinner to select stroke color
Spinner colorSpinner = FindViewById <Spinner>(Resource.Id.colorSpinner);
colorSpinner.ItemSelected += OnColorSpinnerItemSelected;
var adapter = ArrayAdapter.CreateFromResource(this, Resource.Array.colors_array, Android.Resource.Layout.SimpleSpinnerItem);
adapter.SetDropDownViewResource(Android.Resource.Layout.SimpleSpinnerDropDownItem);
colorSpinner.Adapter = adapter;
// Set up the Spinner to select stroke width
Spinner widthSpinner = FindViewById <Spinner>(Resource.Id.widthSpinner);
widthSpinner.ItemSelected += OnWidthSpinnerItemSelected;
var widthsAdapter = ArrayAdapter.CreateFromResource(this, Resource.Array.widths_array, Android.Resource.Layout.SimpleSpinnerItem);
widthsAdapter.SetDropDownViewResource(Android.Resource.Layout.SimpleSpinnerDropDownItem);
widthSpinner.Adapter = widthsAdapter;
// Set up the Clear button
Button clearButton = FindViewById <Button>(Resource.Id.clearButton);
clearButton.Click += OnClearButtonClick;
}
public override void LoadView()
{
base.LoadView();
// White view covering entire screen
UIView contentView = new UIView()
{
BackgroundColor = UIColor.White
};
View = contentView;
// Vertical UIStackView offset from status bar
CGRect rect = UIScreen.MainScreen.Bounds;
rect.Y += 20;
rect.Height -= 20;
UIStackView vertStackView = new UIStackView(rect)
{
Axis = UILayoutConstraintAxis.Vertical,
};
contentView.Add(vertStackView);
// Horizontal UIStackView for tools
UIStackView horzStackView = new UIStackView
{
Axis = UILayoutConstraintAxis.Horizontal,
Alignment = UIStackViewAlignment.Center,
Distribution = UIStackViewDistribution.EqualSpacing
};
vertStackView.AddArrangedSubview(horzStackView);
// FingerPaintCanvasView for drawing
FingerPaintCanvasView canvasView = new FingerPaintCanvasView();
vertStackView.AddArrangedSubview(canvasView);
// Add space at left to horizontal UIStackView
horzStackView.AddArrangedSubview(new UILabel(new CGRect(0, 0, 10, 10)));
// Construct UIPickerView for choosing color, but don't add it to any view
PickerDataModel <UIColor> colorModel = new PickerDataModel <UIColor>
{
Items =
{
new NamedValue <UIColor>("Red", UIColor.Red),
new NamedValue <UIColor>("Green", UIColor.Green),
new NamedValue <UIColor>("Blue", UIColor.Blue),
new NamedValue <UIColor>("Cyan", UIColor.Cyan),
new NamedValue <UIColor>("Magenta", UIColor.Magenta),
new NamedValue <UIColor>("Yellow", UIColor.Yellow),
new NamedValue <UIColor>("Black", UIColor.Black),
new NamedValue <UIColor>("Gray", UIColor.Gray),
new NamedValue <UIColor>("White", UIColor.White)
}
};
UIPickerView colorPicker = new UIPickerView
{
Model = colorModel
};
// Ditto for UIPickerView for stroke thickness
PickerDataModel <float> thicknessModel = new PickerDataModel <float>
{
Items =
{
new NamedValue <float>("Thin", 2),
new NamedValue <float>("Thinish", 5),
new NamedValue <float>("Medium", 10),
new NamedValue <float>("Thickish", 20),
new NamedValue <float>("Thick", 50)
}
};
UIPickerView thicknessPicker = new UIPickerView
{
Model = thicknessModel
};
// Create UIToolbar for dismissing picker when it's displayed
var toolbar = new UIToolbar(new CGRect(0, 0, UIScreen.MainScreen.Bounds.Width, 44))
{
BarStyle = UIBarStyle.Default,
Translucent = true
};
// Set Font to be used in tools
UIFont font = UIFont.SystemFontOfSize(24);
// Create a NoCaretField text field for invoking color picker & add to horizontal UIStackView
// (technique from Xamarin.Forms iOS PickerRenderer
UITextField colorTextField = new NoCaretField
{
Text = "Red",
InputView = colorPicker,
InputAccessoryView = toolbar,
Font = font
};
horzStackView.AddArrangedSubview(colorTextField);
// Use ValueChanged handler to change the color
colorModel.ValueChanged += (sender, args) =>
{
colorTextField.Text = colorModel.SelectedItem.Name;
canvasView.StrokeColor = colorModel.SelectedItem.Value.CGColor;
};
// Ditto for the thickness
UITextField thicknessTextField = new NoCaretField
{
Text = "Thin",
InputView = thicknessPicker,
InputAccessoryView = toolbar,
Font = font
};
horzStackView.AddArrangedSubview(thicknessTextField);
thicknessModel.ValueChanged += (sender, args) =>
{
thicknessTextField.Text = thicknessModel.SelectedItem.Name;
canvasView.StrokeWidth = thicknessModel.SelectedItem.Value;
};
// Now add a Done button to the toolbar to rest text fields
var spacer = new UIBarButtonItem(UIBarButtonSystemItem.FlexibleSpace);
var doneButton = new UIBarButtonItem(UIBarButtonSystemItem.Done, (o, a) =>
{
colorTextField.ResignFirstResponder();
thicknessTextField.ResignFirstResponder();
});
toolbar.SetItems(new[] { spacer, doneButton }, false);
// Create the Clear button
UIButton button = new UIButton(UIButtonType.RoundedRect)
{
Font = font
};
horzStackView.AddArrangedSubview(button);
button.Layer.BorderColor = UIColor.Black.CGColor;
button.Layer.BorderWidth = 1;
button.Layer.CornerRadius = 10;
button.SetTitle("Clear", UIControlState.Normal);
button.SetTitleColor(UIColor.Black, UIControlState.Normal);
button.TouchUpInside += (sender, args) =>
{
canvasView.Clear();
};
// Add space at right to horizontal UIStackView
horzStackView.AddArrangedSubview(new UILabel(new CGRect(0, 0, 10, 10)));
}