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IsDisposed Property
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Leadtools Namespace > RasterImage Class : IsDisposed Property



Gets a value indicating whether the RasterImage object has been disposed of.

Syntax

Visual Basic (Declaration) 
Public ReadOnly Property IsDisposed As Boolean
Visual Basic (Usage)Copy Code
Dim instance As RasterImage
Dim value As Boolean
 
value = instance.IsDisposed
C# 
public bool IsDisposed {get;}
C++/CLI 
public:
property bool IsDisposed {
   bool get();
}

Return Value

true if the RasterImage object has been disposed of; otherwise, false.

Example

This example will show the use of the IsDisposed property of a RasterImage object.

Visual BasicCopy Code
Public Sub IsDisposedTest()
   ' Create a RasterImage objects
   Dim image As New RasterImage( _
      RasterMemoryFlags.Conventional, _
      100, _
      100, _
      24, _
      RasterByteOrder.Bgr, _
      RasterViewPerspective.TopLeft, _
      Nothing, _
      IntPtr.Zero, _
      0)
   ' Check the IsDisposed property, should be false
   Debug.Assert(Not image.IsDisposed)
   MessageBox.Show("IsDisposed = " + image.IsDisposed.ToString())

   ' Now dispose the image
   image.Dispose()

   ' Re-check the IsDisposed property, should be true
   Debug.Assert(image.IsDisposed)
   MessageBox.Show("IsDisposed = " + image.IsDisposed.ToString())
End Sub
C#Copy Code
public void IsDisposedTest() 

   // Create a RasterImage objects 
   RasterImage image = new RasterImage( 
      RasterMemoryFlags.Conventional, 
      100, 
      100, 
      24, 
      RasterByteOrder.Bgr, 
      RasterViewPerspective.TopLeft, 
      null, 
      IntPtr.Zero, 
      0); 
 
   // Check the IsDisposed property, should be false 
   Debug.Assert(!image.IsDisposed); 
   MessageBox.Show("IsDisposed = " + image.IsDisposed.ToString()); 
 
   // Now dispose the image 
   image.Dispose(); 
 
   // Re-check the IsDisposed property, should be true 
   Debug.Assert(image.IsDisposed); 
   MessageBox.Show("IsDisposed = " + image.IsDisposed.ToString()); 
}

Remarks

When this property returns true, the RasterImage object is disposed of and can no longer be referenced as a valid object. Even though the instance of an object is disposed of, it is still maintained in memory until it is removed from memory through garbage collection. When an object is disposed, you should not check any other properties or call any other methods in the control or an NullReferenceException error will occur.

If it is required to track when a RasterImage object is disposed, use the Disposed event.

The RasterImage class implements the IDisposable interface, it is recommended that you follow the standard .NET dispose pattern when using the RasterImage class. For more information, refer to the IDisposable interface documentation in MSDN.

Requirements

Target Platforms: Microsoft .NET Framework 3.0, Windows XP, Windows Server 2003 family, Windows Server 2008 family

See Also