shendashen，获取键盘高度为0，造成输入框不能弹起，这个问题能解决吗？

UIKeyboardWillChangeFrameNotification; userInfo = {
UIKeyboardAnimationCurveUserInfoKey = 7;
UIKeyboardAnimationDurationUserInfoKey = 0;
UIKeyboardBoundsUserInfoKey = "NSRect: {{0, 0}, {414, 0}}";
UIKeyboardCenterBeginUserInfoKey = "NSPoint: {207, 736}";
UIKeyboardCenterEndUserInfoKey = "NSPoint: {207, 736}";
UIKeyboardFrameBeginUserInfoKey = "NSRect: {{0, 736}, {414, 0}}";
UIKeyboardFrameEndUserInfoKey = "NSRect: {{0, 736}, {414, 0}}";
UIKeyboardIsLocalUserInfoKey = 1;
}}