如何在事件可见的情况下制作画布？

Question

i have following problem, i want to generate a little canvas by a button click, after generating i want to move it by a key press event but i cant see the canvas in the event. How can i make it visible? (In the sourcecode of WPF not in XAML)

public void Button_Click_1(object sender, RoutedEventArgs e)
{   
    Canvas c = new Canvas();
    c.Height = System.Windows.SystemParameters.PrimaryScreenHeight;
    c.Width = System.Windows.SystemParameters.PrimaryScreenWidth;
    c.Loaded += c_Loaded;
    Grid.Children.Add(c);

    Canvas ship = new Canvas();
    ship.Background = Brushes.Aquamarine;
    ship.Height = 30;
    ship.Width = 30;
    ship.KeyDown += ship_KeyDown;
    Canvas.SetTop(ship, 50);
    c.Children.Add(ship);  
}

void ship_KeyDown(object sender, KeyEventArgs e)
{
    canvas.Setleft(ship, canvas.Getleft(ship) +10);  //here i can not see the object "ship" :(          
}

Answer 1

使用参数发送者：

Canvas ship = (Canvas) sender;

Answer 2

您需要添加c或运送到layoutroot`

Answer 3

最简单的方法是将其添加到UIElement的<list>并使用foreach -loop进行修改