拖放函数,采样函数返回值

enum DragStatus {
  kNoChange = -6,
  kCancel = -4,
  kOther = -3,
  kNull = -1,
  kNormal = 0,
  kKW1 = 1,
  kKW2,
  kKW3,
  kKW4,
  kKW5,
  kKW6,
  kKW7,
  kKW8,
  kKW9,
  kKW10,
  kKW11,
  kKW12,
  kKW13,
  kKW14,
  kKW15,
  kKW16,
  kKW17,
  kKW18,
  kKW19,
  kKW20
};