Delete All Shapes of a PowerPoint Slide

Question

I tried to delete all shapes with the following piece of codes:

PowerPoint.Application ppApp = Globals.ThisAddIn.Application;
PowerPoint.Presentation ppP = ppApp.ActivePresentation;
PowerPoint.Slide ppS = ppApp.ActiveWindow.Selection.SlideRange[1];
PowerPoint.Shapes shapes = ppS.Shapes;

foreach (PowerPoint.Shape shape in shapes)
{
      shape.Delete(shape);                    
}

It cannot delete all shapes as I expected, because when a shape is deleted, it will affect the PowerPoint.Shapes. If I want to delete all shapes, I need to add all shapes into a List, and then delete each one like:

PowerPoint.Application ppApp = Globals.ThisAddIn.Application;
PowerPoint.Presentation ppP = ppApp.ActivePresentation;
PowerPoint.Slide ppS = ppApp.ActiveWindow.Selection.SlideRange[1];
PowerPoint.Shapes shapes = ppS.Shapes;
if (shapes == null) return;

List listShapes = new List();
foreach (PowerPoint.Shape shape in shapes)
{
      listShapes.Add(shape);                    
}

foreach (PowerPoint.Shape shape in listShapes)
{
      shape.Delete();
}

Is there any other ways to delete faster?

Answer 1

You can't iterate over a collection and delete an item from that collection, because that affects the collection. So just try avoiding the for-each loop:

while (shapes.Count > 0) {
  shapes[0].Delete();
}

Not 100% sure of the syntax in relationship to PowerPoint, but that's the general idea.