setAnimationDuration 方法：定義動畫的時間嘁傀。
setAnimationCurve 方法：定義動畫的軌跡（動畫如何執(zhí)行）

 
typedef NS_ENUM(NSInteger, UIViewAnimationCurve) {
    UIViewAnimationCurveEaseInOut,         // 開始時慢兴蒸，中間快，結(jié)束時慢
    UIViewAnimationCurveEaseIn,            // 開始慢细办，然后加速
    UIViewAnimationCurveEaseOut,           // 逐漸減速
    UIViewAnimationCurveLinear             // 勻速
};


 [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(keyboardChangeFrame:) name:UIKeyboardWillChangeFrameNotification object:nil];
 [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(keyboardHide:) name:UIKeyboardWillHideNotification object:nil];


-(void)keyboardChangeFrame:(NSNotification*)noti;
{
    
    CGRect rect= [noti.userInfo[UIKeyboardFrameEndUserInfoKey]CGRectValue];
    NSLog(@"%@", noti.userInfo);
    CGFloat keyboardheight = rect.origin.y;
    CGFloat duration=[noti.userInfo[UIKeyboardAnimationDurationUserInfoKey]doubleValue];
    CGFloat curve=[noti.userInfo[UIKeyboardAnimationCurveUserInfoKey]doubleValue];
    [_messageTable zxp_updateConstraints:^(ZXPAutoLayoutMaker *layout) {
        layout.top.offset(0);
        layout.left.offset(0);
        layout.right.offset(0);
        layout.height.offset(keyboardheight-30-80);
    }];
    [_sendTextView zxp_updateConstraints:^(ZXPAutoLayoutMaker *layout) {
        layout.left.offset(0);
        layout.right.offset(0);
        layout.height.offset(45);
        layout.top.equalTo(_messageTable.zxp_bottom).offset(0);
    }];
    [UIView setAnimationCurve:curve];
    [UIView animateWithDuration:duration animations:^{
        [self.view layoutIfNeeded];
        [self tableScrollToBottom];
    } completion:^(BOOL finished) {
        
    }];
    
}


-(void)keyboardHide:(NSNotification *)noti
{
    [self.view endEditing:YES];

    [UIView animateWithDuration:0.3 animations:^{
            
        _inputView.frame = CGRectMake(0, ScreenViewWH-260-110, ScreenViewW, 260);
        [_inputView mas_updateConstraints:^(MASConstraintMaker *make) {
            make.left.offset(0);
            make.right.offset(0);
            make.bottom.offset(-64);
            make.height.offset(260);
        }];
        [self.view layoutIfNeeded];
        
    } completion:^(BOOL finished) {
        
    }];

}