Question

我有一个UITableView，包含3个原型单元格和3个自定义单元格类： FriendCell FriendRequestCell和AddFriendCell。

初始化后，表格显示Friends。

如果有FriendRequests，则会在Friends上方的部分中显示它们。

如果没有FriendRequests，则只显示Friends。

但是，我还有一个UISearchBar来搜索用户，当它有结果时，应该返回AddFriendCell并重新加载表。

相反，我明白了：

代码：

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    if searching == true {
        if let cell = tableView.dequeueReusableCellWithIdentifier("AddFriendCell", forIndexPath: indexPath) as? AddFriendCell {
            let resultCell = userResults[indexPath.row]
            cell.configureCell(resultCell)
        }
    } else {
        if friendRequests.isEmpty ||  (indexPath.section == 1)  {
            if let cell = tableView.dequeueReusableCellWithIdentifier("FriendCell", forIndexPath: indexPath) as? FriendCell {
                let friendCell = friends[indexPath.row]
                cell.configureCell(friendCell)
            }
        } else {
            if (indexPath.section == 0) {
                if let cell = tableView.dequeueReusableCellWithIdentifier("FriendRequestCell", forIndexPath: indexPath) as? FriendRequestCell {
                    let friendRequestCell = friendRequests[indexPath.row]
                    cell.configureCell(friendRequestCell)
                }
            }
        }
    }
    return FriendCell()
}


func numberOfSectionsInTableView(tableView: UITableView) -> Int {
    if searching == true {
        return 1
    } else {
        return friendsDataSource.count
    }
}

func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    if searching == true {
        return userResults.count
    } else {
        return friendsDataSource[section].count
    }
}

func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
    if searching == true {
        return nil
    } else {
        if friendsDataSource.count > 1 {
            if section == 0 {
                return "Friend Requests"
            } else if section == 1 {
                return "Friends"
            }
        } else {
             return "Friends"
        }
        return "Friends"
    }
}

func tableView(tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
    if searching == true {
        return 0
    } else {
        return 25
    }
}

func searchBarSearchButtonClicked(searchBar: UISearchBar) {
    searching = true
    searchBar.resignFirstResponder()
    userResults = [UserProfile]()
    activitySpinner.startAnimating()

    if let searchText = searchBar.text {
        let userProfileQuery = PFQuery(className: "UserProfile")
        userProfileQuery.whereKey("username", containsString: searchText)

        userProfileQuery.findObjectsInBackgroundWithBlock({ resultArray, error in
            if error != nil {
                print("there's been an error searching for users: \(error)")

            } else if let resultArray = resultArray {
                print("number of results: \(resultArray.count)")
                self.parseResults = resultArray

                for userProfile in resultArray {
                    let username = userProfile["username"] as! String
                    let profilePicUrl = userProfile["profilePicUrl"] as! String
                    let parseObjectId = userProfile.objectId!

                    let newProfile = UserProfile(username: username, profilePicUrl: profilePicUrl, parseObjectId: parseObjectId)
                    self.userResults.append(newProfile)
                }
                self.tableView.reloadData()
                self.activitySpinner.stopAnimating()
            }
        })
    }
}

关于问题根源的任何想法？

Answer 1

如果方法findObjectsInBackgroundWithBlock是异步的，我认为您可以使用self.tableView.reloadData()代替dispatch_async(dispatch_get_main_queue(), { self.tableView.reloadData() }) 添加self.tableView.rowHeight = 50

并且您不会返回您的addfriendcell。你只需在最后一行返回FriendsCell（）。添加返回单元格。

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    if searching == true {
        if let cell = tableView.dequeueReusableCellWithIdentifier("AddFriendCell", forIndexPath: indexPath) as? AddFriendCell {
            let resultCell = userResults[indexPath.row]
            cell.configureCell(resultCell)
            return cell! //add the return
        }
    } else {
        if friendRequests.isEmpty ||  (indexPath.section == 1)  {
            if let cell = tableView.dequeueReusableCellWithIdentifier("FriendCell", forIndexPath: indexPath) as? FriendCell {
                let friendCell = friends[indexPath.row]
                cell.configureCell(friendCell)
                return cell! //add the return
            }
        } else {
            if (indexPath.section == 0) {
                if let cell = tableView.dequeueReusableCellWithIdentifier("FriendRequestCell", forIndexPath: indexPath) as? FriendRequestCell {
                    let friendRequestCell = friendRequests[indexPath.row]
                    cell.configureCell(friendRequestCell)
                    return cell! //add the return
                }
            }
        }
    }
    return FriendCell()
}

Answer 2

好的，这是多种类型的单元格的代码：

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    if searching == true {

        let cell = tableView.dequeueReusableCellWithIdentifier("AddFriendCell", forIndexPath: indexPath) as! AddFriendCell

        // ...configure your cell...

        return cell 
    } 
    else{
        if friendRequests.isEmpty ||  (indexPath.section == 1)  {

            let cell = tableView.dequeueReusableCellWithIdentifier("FriendCell", forIndexPath: indexPath) as! FriendCell

            // ...configure your cell...

            return cell            
        } 
        else{
            if (indexPath.section == 0) {

                let cell = tableView.dequeueReusableCellWithIdentifier("FriendRequestCell", forIndexPath: indexPath) as! FriendRequestCell

                 // ...configure your cell...

                return cell
            }
            else {
                // Decide what to do if section is NOT 0. If this CAN happen
                // and you don't have a cell type to return, it is a design flaw.
                // don't add a adummy "return FriendCell()" as a fallback for a
                // case that should never happen, to make the compiler happy. 
                // This type of error should be caught during development.
            }
        }
    }
}

（参见关于如何处理未经移植的执行路径的评论段落）

或者，您可以在所有if / else块之外将cell声明为var类型UITableViewCell，将其分配给内部适当的已出列单元格，（即删除{ {1}}关键字，如果修改上面的代码，并在最后返回。

但是你仍然需要确保在返回之前初始化它。

不同的UITableViewCells重叠

2 个答案: