WPF ziehen Grenze in Container

Question

Ich möchte Bereich innerhalb eines Containers zeichnen. Hierfür habe ich über die Verwendung von benutzerdefinierten Steuerelementen nachgedacht.

Mein Problem ist, dass Canvas nicht den gesamten Platz beansprucht, den es bekommt. Wie erzwingen Sie es verwenden Sie alle verfügbaren Speicherplatz?

Was ich habe, ist getan von Canvas geerbt und im Inneren Randelement erstellt:

public class DrawableCanvas : Canvas 
{ 
    private Border border; 

    static DrawableCanvas() 
    { 
     DefaultStyleKeyProperty.OverrideMetadata(typeof(DrawableCanvas), new FrameworkPropertyMetadata(typeof(DrawableCanvas))); 
    } 

    public DrawableCanvas() 
    { 
     this.border = new Border(); 
     border.Background = new SolidColorBrush(Colors.Blue); 
     border.BorderThickness = new Thickness(1); 
     border.Width = 0; 
     border.Visibility = Visibility.Hidden; 
     border.Opacity = 0.3; 

     this.Children.Add(border); 

     this.MouseLeftButtonDown += DrawableCanvas_MouseLeftButtonDown; 
     this.MouseLeftButtonUp += DrawableCanvas_MouseLeftButtonUp; 
     this.MouseMove += DrawableCanvas_MouseMove; 
    } 

    private void DrawableCanvas_MouseLeftButtonUp(object sender, MouseButtonEventArgs e) 
    { 
     Debug.WriteLine("Left mouse up"); 

     // release mouse 
     Mouse.Capture(null); 

     border.Width = 0; 
     border.Height = 100; 

     startPosition = 0; 
    } 

    double startPosition = 0; 
    private void DrawableCanvas_MouseLeftButtonDown(object sender, MouseButtonEventArgs e) 
    { 
     Debug.WriteLine("Left mouse down"); 

     border.Visibility = Visibility.Visible; 

     // capture mouse 
     Mouse.Capture(this); 

     var point = e.GetPosition(this); 
     startPosition = point.X; 

     SetLeft(border, point.X); 
    } 

    private void DrawableCanvas_MouseMove(object sender, MouseEventArgs e) 
    { 
     if(this.IsMouseCaptured) 
     { 
      var point = e.GetPosition(this); 

      Debug.WriteLine("Mouse move"); 

      // set the position to far left 
      SetLeft(border, Math.Min(startPosition, point.X)); 

      // width is the difference between two points 
      border.Width = Math.Abs(startPosition - point.X); 

      Debug.WriteLine(Math.Min(startPosition, point.X)); 
      Debug.WriteLine(border.Width); 
     } 
    } 
} 

Und für Ansicht:

<DockPanel> 
    <local:DrawableCanvas> 
     <Rectangle Height="500" Width="500" Fill="Transparent" /> 
    </local:DrawableCanvas> 
</DockPanel> 

Ich möchte etwas wie folgt aus:

Answer 1

Was Ich wollte dieses Steuerelement erstellen, um die Auswahl auf ui zu ermöglichen.

Dazu brauchte ich eine Grenze/Rechteck, das nur in der Breite überspannen wird und verbrauchen alle die Höhe wird es

ich damit endete:

Ausblick:

<Window x:Class="Wpf.Test01.Stack_43281567" 
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
     xmlns:local="clr-namespace:Wpf.Test01.Controls" 
     mc:Ignorable="d" 
     Title="Stack_43281567" Height="300" Width="300"> 
    <Grid> 
     <local:DrawableCanvas /> 
    </Grid> 
</Window> 

DrawableCanvas.cs:

public class DrawableCanvas : Canvas 
{ 
    private Border border; 

    static DrawableCanvas() 
    { 
     DefaultStyleKeyProperty.OverrideMetadata(typeof(DrawableCanvas), new FrameworkPropertyMetadata(typeof(DrawableCanvas))); 
    } 

    // when selection is done expose event to notify the user of selection change 

    public DrawableCanvas() 
    { 
     this.border = new Border(); 
     border.Background = new SolidColorBrush(Colors.Blue); 
     border.BorderThickness = new Thickness(1); 
     border.Visibility = Visibility.Hidden; 
     border.Opacity = 0.3; 
     border.Height = this.ActualHeight; 

     this.Children.Add(border); 
     this.Background = new SolidColorBrush(Colors.Transparent); 

     this.MouseLeftButtonDown += DrawableCanvas_MouseLeftButtonDown; 
     this.MouseLeftButtonUp += DrawableCanvas_MouseLeftButtonUp; 
     this.MouseMove += DrawableCanvas_MouseMove; 

     this.SizeChanged += DrawableCanvas_SizeChanged; 
    } 

    private void DrawableCanvas_SizeChanged(object sender, SizeChangedEventArgs e) 
    { 
     border.Height = e.NewSize.Height; 
    } 

    private void DrawableCanvas_MouseLeftButtonUp(object sender, MouseButtonEventArgs e) 
    { 
     Debug.WriteLine("Left mouse up"); 

     // release mouse 
     Mouse.Capture(null); 

     border.Width = 0; 

     startPosition = 0; 
    } 

    double startPosition = 0; 
    private void DrawableCanvas_MouseLeftButtonDown(object sender, MouseButtonEventArgs e) 
    { 
     Debug.WriteLine("Left mouse down"); 

     border.Visibility = Visibility.Visible; 

     // capture mouse 
     Mouse.Capture(this); 

     var point = e.GetPosition(this); 
     startPosition = point.X; 

     SetLeft(border, point.X); 
    } 

    private void DrawableCanvas_MouseMove(object sender, MouseEventArgs e) 
    { 
     if (this.IsMouseCaptured) 
     { 
      var point = e.GetPosition(this); 

      Debug.WriteLine("Mouse move"); 

      // set the position to far left 
      SetLeft(border, Math.Min(startPosition, point.X)); 

      // width is the difference between two points 
      border.Width = Math.Abs(startPosition - point.X); 

      Debug.WriteLine(Math.Min(startPosition, point.X)); 
      Debug.WriteLine(border.Width); 
     } 
    } 
}