IOS实现聊天界面底部菜单栏效果

测试代码：

-(void) testBottomMenu{ 
   self.menu = [[BottomMenuView alloc] init]; 
  self.menu.translatesAutoresizingMaskIntoConstraints = NO; 
  //self.menu.backgroundColor = [UIColor redColor]; 
  [self.menu buildOptionMenu]; 
  self.menu.delegate = self; 
  [self.view addSubview:self.menu]; 
  //使用约束来达到效果，下面开始添加约束 靠着底部 
  NSLayoutConstraint* alginBottom = [NSLayoutConstraint constraintWithItem:self.menu 
                                  attribute:NSLayoutAttributeBottom 
                                  relatedBy:NSLayoutRelationEqual 
                                   toItem:self.view 
                                  attribute:NSLayoutAttributeBottom 
                                 multiplier:1 
                                  constant:0.0]; 
  [self.view addConstraint:alginBottom]; 
  //添加高度 
  self.bottomHeightCons = [NSLayoutConstraint 
               constraintWithItem:self.menu 
               attribute:NSLayoutAttributeHeight 
               relatedBy:NSLayoutRelationEqual 
               toItem:nil 
               attribute:0 
               multiplier:1 
               constant:260]; 
  [self.menu addConstraint:self.bottomHeightCons]; 
  //添加右边约束 
  NSLayoutConstraint* rightMargin = [NSLayoutConstraint constraintWithItem:self.menu 
                                  attribute:NSLayoutAttributeRight 
                                  relatedBy:NSLayoutRelationEqual 
                                   toItem:self.view 
                                  attribute:NSLayoutAttributeRight 
                                 multiplier:1 
                                  constant:0.0]; 
  [self.view addConstraint:rightMargin]; 
  //添加左边约束 
  NSLayoutConstraint* leftMargin = [NSLayoutConstraint constraintWithItem:self.menu 
                                  attribute:NSLayoutAttributeLeft 
                                  relatedBy:NSLayoutRelationEqual 
                                   toItem:self.view 
                                  attribute:NSLayoutAttributeLeft 
                                 multiplier:1 
                                  constant:0.0]; 
  [self.view addConstraint:leftMargin]; 
} 
//更多操作按钮的协议监听接口 
-(void)onChangListener{ 
  //[self.view layoutIfNeeded]; 
  if(self.bottomHeightCons.constant == 40){ 
    self.bottomHeightCons.constant = 260; 
  }else{ 
    self.bottomHeightCons.constant = 40; 
  } 
  [UIView animateWithDuration:0.5 animations:^{ 
    [self.view layoutIfNeeded]; 
  }];    
}