MB_SYSTEMMODAL top-level constant Null safety
Same as MB_APPLMODAL except that the message box has the WS_EX_TOPMOST style.
Use system-modal message boxes to notify the user of serious, potentially damaging errors that require immediate attention (for example, running out of memory). This flag has no effect on the user's ability to interact with windows other than those associated with hWnd.
const MB_SYSTEMMODAL = 0x00001000;