Excel 和 PowerPoint 都可以有 Shape 对象.您的:

Excel and PowerPoint can both have Shape objects. Your:

Dim myTextbox As Shape

准备 Excel 以期待 Excel 形状.改成

prepares Excel to expect an Excel shape. Change it to

Dim myTextbox As PowerPoint.Shape

因此，当您尝试将 PowerPoint 属性和方法应用于 Excel 形状时，Excel 不会吠叫.

so Excel doesn't bark when you try to apply PowerPoint properties and methods to an Excel shape.