I've been trying to swap images in a PictureBox in a C++/CLI application but my solution appears to have a memory leak:
System::Void button1_Click(System::Object^ sender, System::EventArgs^ e)
{
// Pick a new bitmap
static int resource = IDB_BITMAP1;
if( resource == IDB_BITMAP2)
{
resource = IDB_BITMAP1;
}
else
{
resource = IDB_BITMAP2;
}
// Get the primary module
Module^ mod = Assembly::GetExecutingAssembly()->GetModules()[0];
// Get the instance handle
IntPtr hinst = Marshal::GetHINSTANCE(mod);
// Get the bitmap as unmanaged
HANDLE hbi = LoadImage((HINSTANCE) hinst.ToPointer(),MAKEINTRESOURCE(resource),IMAGE_BITMAP,0,0,LR_DEFAULTCOLOR);
// Import the unmanaged bitmap into the managed side
Bitmap^ bi = Bitmap::FromHbitmap(IntPtr(hbi)开发者_开发百科);
// Remove any previously stored images
if(m_pictureBox1->Image != nullptr)
{
delete m_pictureBox1->Image;
m_pictureBox1->Image = nullptr;
}
// Insert the bitmap into the picture box
m_pictureBox1->Image = bi;
// Free up the unmanaged bitmap
DeleteObject(hbi);
}
As far as I can see, I'm explicitely releasing the memory so why does task manager report an ~24k increase in memory each time the button is clicked?
two words: garbage collection
Bizarrely, this actually looks to be caused when you mouse-over the button. Each time you do that the memory jumps but after enough mouse-overs that memory usage stabilises. The actual clicks on the button (i.e. calls to my routine) don't cause any leakage.
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