OFN_ENABLESIZING top-level constant Null safety
Enables the Explorer-style dialog box to be resized using either the mouse or the keyboard. By default, the Explorer-style Open and Save As dialog boxes allow the dialog box to be resized regardless of whether this flag is set. This flag is necessary only if you provide a hook procedure or custom template. The old-style dialog box does not permit resizing.
const OFN_ENABLESIZING = 0x00800000;