Canvas::Left Attached Property

Gets or sets a value that represents the distance between the left side of an element and the left side of its parent Canvas.

Namespace:  System.Windows.Controls
Assembly:  PresentationFramework (in PresentationFramework.dll)
XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation

See GetLeft, SetLeft
<object Canvas.Left="double" .../>

Property Value

Type: System::Double
A Double that represents the offset position from the left side of a parent Canvas. The default value is NaN.

Identifier field

LeftProperty

Metadata properties set to true

None

The Left offset of a child element does not affect the size of a parent Canvas.

If you specify them, the attached properties Canvas::Top or Canvas::Left take priority over Canvas::Bottom or Canvas::Right properties.

This example shows how to use the attached properties of Canvas to position child elements.

The following example adds four Button elements as child elements of a parent Canvas. Each child element represents a distinct attached property of Canvas: Bottom, Left, Right, and Top. Each Button is positioned relative to the parent Canvas and according to its assigned property value.

// Create the application's main window
mainWindow = gcnew System::Windows::Window();
mainWindow->Title = "Canvas Attached Properties Sample";

// Add a Border
Border^ myBorder = gcnew Border();
myBorder->HorizontalAlignment = HorizontalAlignment::Left;
myBorder->VerticalAlignment = VerticalAlignment::Top;
myBorder->BorderBrush = Brushes::Black;
myBorder->BorderThickness = System::Windows::Thickness(2);

// Create the Canvas
Canvas^ myCanvas = gcnew Canvas();
myCanvas->Background = Brushes::LightBlue;
myCanvas->Width = 400;
myCanvas->Height = 400;

// Create the child Button elements
Button^ myButton1 = gcnew Button();
Button^ myButton2 = gcnew Button();
Button^ myButton3 = gcnew Button();
Button^ myButton4 = gcnew Button();

// Set Positioning attached properties on Button elements
Canvas::SetTop(myButton1, 50);
myButton1->Content = "Canvas.Top=50";
Canvas::SetBottom(myButton2, 50);
myButton2->Content = "Canvas.Bottom=50";
Canvas::SetLeft(myButton3, 50);
myButton3->Content = "Canvas.Left=50";
Canvas::SetRight(myButton4, 50);
myButton4->Content = "Canvas.Right=50";

// Add Buttons to the Canvas' Children collection
myCanvas->Children->Add(myButton1);
myCanvas->Children->Add(myButton2);
myCanvas->Children->Add(myButton3);
myCanvas->Children->Add(myButton4);

// Add the Canvas as the lone Child of the Border
myBorder->Child = myCanvas;

// Add the Border as the Content of the Parent Window Object
mainWindow->Content = myBorder;
mainWindow->Show();
<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" WindowTitle="Canvas Attached Properties Sample">
  <Border HorizontalAlignment="Left" VerticalAlignment="Top" BorderBrush="Black" BorderThickness="2">
    <Canvas Background="LightBlue" Width="400" Height="400">
      <Button Canvas.Top="50">Canvas.Top="50"</Button>
      <Button Canvas.Bottom="50">Canvas.Bottom="50"</Button>
      <Button Canvas.Left="50">Canvas.Left="50"</Button>
      <Button Canvas.Right="50">Canvas.Right="50"</Button>
    </Canvas>
  </Border>    
</Page>

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0
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