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The PictureBox control is not designed to allow drag and drop procedures. However, since PictureBox inherits from control, it also inherits the AllowDrop property. To clarify this, in the next release of the documentation, the PictureBox.AllowDrop topic will be marked with the “for internal use only” boilerplate. Also, the PictureBox.AllowDrop property will not appear in intellisense if you are using the Visual Studio text editor.