Bug in Rectangle Drawing (SL2 B1)

05-14-2008 10:46 AM |

All,

Please check out the following simple code. If you hold down mouse button and drag mouse thru canvas, the rectangle is expected to draw/refresh itself. It does draw rectangle "except the Stroke" used for border. If you notice there is a small "Aaua" dot at left/top corner when you start dragging indicating the presence of stroke. Can somebody provide a solution to this issue?

Thanks

Nilk 

<UserControl x:Class="Tryouts.Page"
    xmlns="http://schemas.microsoft.com/client/2007"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Width="400" Height="300">
    <Canvas Width="400" Height="300"
                Canvas.Left="0" Canvas.Top="0" Canvas.ZIndex="1"
                Background="DarkBlue"
                MouseLeftButtonDown="MyMouseLeftButtonDown"
                MouseLeftButtonUp="MyMouseLeftButtonUp"
                MouseMove="MyMouseMove">

        <Button x:Name="BtnTest"  Click="BtnTest_Click" Width="200" Height="30" Canvas.Left="150" Canvas.Top="5" Content="Move Mouse in Blue Area"></Button>
        <Rectangle  x:Name="RecSelection" 
                    Height="100" Width="100"
                    Canvas.Left="0" Canvas.Top="0" Canvas.ZIndex="10"
                    Fill="#7F92B5F4" Stroke="Aqua"
                    StrokeThickness="1"
                    Visibility="Collapsed"/>
    </Canvas>
</UserControl>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;

namespace Tryouts
{
    public partial class Page : UserControl
    {
        Point MouseBeginPosition;

        public Page()
        {
            InitializeComponent();
        }

        private void BtnTest_Click(object sender, RoutedEventArgs e)
        {
            this.RecSelection.Width = 30;
            this.RecSelection.Height = 200;
            this.RecSelection.Visibility = Visibility.Visible;
        }

        private void MyMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            MouseBeginPosition = e.GetPosition(this);
            if (RecSelection.Visibility == Visibility.Collapsed)
            {
                ResetRectangle(MouseBeginPosition.Y, MouseBeginPosition.X);
                RecSelection.Visibility = Visibility.Visible;
            }
        }

        private void MyMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
        {
            if (RecSelection.Visibility == Visibility.Visible)
            {
                RecSelection.Visibility = Visibility.Collapsed;
                ResetRectangle(-1, -1);
            }

            MouseBeginPosition = e.GetPosition(this);

        }

        private void MyMouseMove(object sender, MouseEventArgs e)
        {
            Point CurrentLocation = e.GetPosition(this);

            if (RecSelection.Visibility == Visibility.Visible)
                DrawSelectionRectangle(MouseBeginPosition, CurrentLocation);

        }

        private void DrawSelectionRectangle(Point From, Point To)
        {
            RecSelection.Visibility = Visibility.Visible;
           
            RecSelection.Width = Math.Abs(From.X - To.X);
            RecSelection.Height = Math.Abs(From.Y - To.Y);
            if (From.X > To.X)
                RecSelection.SetValue(Canvas.LeftProperty, To.X);
            else
                RecSelection.SetValue(Canvas.LeftProperty, From.X);

            if (From.Y > To.Y)
                RecSelection.SetValue(Canvas.TopProperty, To.Y);
            else
                RecSelection.SetValue(Canvas.TopProperty, From.Y);

            RecSelection.Visibility = Visibility.Visible;
        }

        private void ResetRectangle(double Top, double Left)
        {
            if (Top > -1)
            {
                RecSelection.SetValue(Canvas.TopProperty, Top);
            }
            if (Left > -1)
            {
                RecSelection.SetValue(Canvas.LeftProperty, Left);
            }
            RecSelection.Width = 0;
            RecSelection.Height = 0;
            RecSelection.Visibility = Visibility.Visible;
        }
    }
}

Re: Bug in Rectangle Drawing (SL2 B1)

05-16-2008 9:00 AM |

Yi-Lun Luo,

Thanks for the update. The workaround is prefect. I worked like champ.

Regards

Nilk