建立cell
tableView的cell效果如下：
image.png
为了建立该cell，我们需要自定义头像UIImage，姓名、日期以及评论区域三个label：
self.avatarImage = UIImageView(frame: CGRectMake(8,8,40,40))
self.avatarImage?.layer.cornerRadius = 20
self.avatarImage?.layer.masksToBounds = true
self.contentView.addSubview(self.avatarImage!)
self.nameLabel = UILabel(frame: CGRectMake(56,8,SCREEN_WIDTH-56-8,15))
self.nameLabel?.font = UIFont(name: MY_FONT, size: 13)
self.contentView.addSubview(self.nameLabel!)
self.dateLabel = UILabel(frame: CGRectMake(56,self.frame.size.height-8-10,SCREEN_WIDTH-56-8,10))
self.dateLabel?.font = UIFont(name: MY_FONT, size: 13)
self.dateLabel?.textColor = UIColor.grayColor()
self.contentView.addSubview(self.dateLabel!)
self.detailLabel = UILabel(frame: CGRectMake(56,30,SCREEN_WIDTH-56-8,self.frame.size.height - 30 - 25))
self.detailLabel?.font = UIFont(name: MY_FONT, size: 15)
self.detailLabel?.numberOfLines = 0
self.contentView.addSubview(self.detailLabel!)
为了实现评论区高度自适应，还需添加如下语句，用于定义每个cell的高度：
func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
let object = self.dataArray[indexPath.row] as? AVObject
let text = object!["text"] as? NSString
let textSize = text?.boundingRectWithSize(CGSizeMake(SCREEN_WIDTH-56-8,0), options: .UsesLineFragmentOrigin, attributes: [NSFontAttributeName:UIFont.systemFontOfSize(15)], context: nil).size
return (textSize?.height)! + 30 + 25
}
注意运行顺序：
1、调用PresentViewController时，是在初始化VC时就初始化Viewdidload；该错误导致tableView无显示；
2、cell在执行tableView之前执行，那么tableView自定义高度变得无法实现；需要在执行定义tableview cell时加载cell初始化；不然会导致cell高度错误
上拉与加载
为了使tableview能实现上拉与加载需要在viewdidload时添加上拉与加载的响应：
self.tableView?.mj_header = MJRefreshNormalHeader(refreshingTarget: self, refreshingAction: "headerRefresh")
self.tableView?.mj_footer = MJRefreshBackNormalFooter(refreshingTarget: self, refreshingAction: "footerRefresh")
然后从LeanCloud中得到数组，并对数组排序；limit是限制一个tableview显示多少个数据，skip表示一次跳过多少个数据；whereKey表示依据什么排序，最后把排序好的dataarray加载进数组并reload tableview：
/**
* 上拉加载、下拉刷新
*/
func headerRefresh(){
let query = AVQuery(className: "discuss")
query.orderByDescending("createdAt")
query.limit = 20
query.skip = 0
query.whereKey("user", equalTo: AVUser.currentUser())
query.whereKey("BookObject", equalTo: self.BookObject)
query.includeKey("user")
query.includeKey("BookObject")
query.findObjectsInBackgroundWithBlock { (results, error) -> Void in
self.tableView?.mj_header.endRefreshing()
self.dataArray.removeAllObjects()
self.dataArray.addObjectsFromArray(results)
self.tableView?.reloadData()
}
}
func footerRefresh(){
let query = AVQuery(className: "discuss")
query.orderByDescending("createdAt")
query.limit = 20
query.skip = self.dataArray.count
query.whereKey("user", equalTo: AVUser.currentUser())
query.whereKey("BookObject", equalTo: self.BookObject)
query.includeKey("user")
query.includeKey("BookObject")
query.findObjectsInBackgroundWithBlock { (results, error) -> Void in
self.tableView?.mj_footer.endRefreshing()
self.dataArray.addObjectsFromArray(results)
self.tableView?.reloadData()
}
}
评论栏InputView
为了在下方添加一个评论栏，需要加载一个第三方库InputView，并ViewController中添加进去：
self.input = NSBundle.mainBundle().loadNibNamed("InputView", owner: self, options: nil).last as? InputView
self.input?.frame = CGRectMake(0,SCREEN_HEIGHT-44,SCREEN_WIDTH,44)
self.input?.delegate = self
self.view.addSubview(self.input!)
为了实现InputView功能，需要实现InputView相关的代理方法，譬如：textViewHeightDidChange、textViewHeightDidChange、keyboardWillHide以及keyboardWillHide；实现键盘的出现和隐藏以及高低变化，在这个观察中Input的view相应bottom也会随之改变。
为了实现评论完后，InputView复原；还需要在keyboardWillHide中添加如下代码：
func keyboardWillHide(inputView: InputView!, keyboardHeight: CGFloat, animationDuration duration: NSTimeInterval, animationCurve: UIViewAnimationCurve) {
UIView.animateWithDuration(duration, delay: 0, options: .BeginFromCurrentState, animations: { () -> Void in
self.layView?.alpha = 0
self.input?.bottom = SCREEN_HEIGHT
}) { (finish) -> Void in
self.layView?.hidden = true
self.input?.resetInputView()
self.input?.inputTextView?.text = ""
self.input?.bottom = SCREEN_HEIGHT
}
}