Question

我想知道在添加子项之前是否有刷新画布的方法？我有这个代码，它画了一个浅蓝色笔画的黑色椭圆。现在我想在程序启动时更改StrokeThickness（我有一个滑块来定义StrokeThickness）。问题是StrokeThickness被改变了，但只有当我重绘椭圆时，我想要在移动滑块时进行更改。有任何想法吗？谢谢！

            //this code is in canvas_MouseDown
            double smt = sliderThickness.Value;

            //krog
            elip = new Ellipse
            {
                Width = 100,
                Height = 100,
                Fill = Brushes.Black,
                Stroke = Brushes.LightBlue,
                StrokeThickness = smt,
            };

            Canvas.SetLeft(elip, mouseX - 50);
            Canvas.SetTop(elip, mouseY - 50);

            canvas1.Children.Add(elip);

Answer 1

在滑块值Changedevent中你必须输入以下代码

 private void sliderThickness_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
    {
        foreach (var item in canvas1.Children)
        {
            if (item is Ellipse)
            {
                var elip = item as Ellipse;
                elip.StrokeThickness = sliderThickness.Value;
            }
        }
    }

Answer 2

或更短

// using System.Linq;

foreach (var ellipse in canvas1.Children.OfType<Ellipse>())
{
    ellipse.StrokeThickness = sliderThickness.Value;
}

Wpf画布刷新

2 个答案: