5

我是 swift 新手，在 PlacesTableViewController 类中声明我的初始化程序时遇到问题。它提示我“在从初始化程序返回之前未调用 Super.init”，当我添加 Super.init 时，它提示我：

“必须调用超类 'UITableViewController' 的指定初始化程序”

这是我的 PlacesTableViewController.swift 文件：

class PlacesTableViewController: UITableViewController { 

    var pa55DB : COpaquePointer = nil
    var selectStatement : COpaquePointer = nil;

    var chapterdata : Array<Entry> = []
    var ety : Entry
    var sqlString : String = "";

    var chpData : ChapterData

    init(pa55DB : COpaquePointer,selectStatement : COpaquePointer, chapterdata : Array<Entry>, ety : Entry, sqlString : String) {
        super.init()
        self.pa55DB = pa55DB
        self.selectStatement = selectStatement
        self.chapterdata = chapterdata
        self.ety = ety
        self.sqlString = sqlString

    }

    required init!(coder aDecoder: NSCoder!) {
        fatalError("init(coder:) has not been implemented")
    }


    override func viewDidLoad() {
        super.viewDidLoad()

        chpData = ChapterData(newEntryArray : chapterdata, entryV : ety, paDB55 : pa55DB, selectStatement : selectStatement, sqlString : sqlString)
        chpData.openDB()
        chapterdata = chpData.prepareStartment()

        println("Testing...")
    }
...
}

这是我的另一个名为 ChapterData.swift 的类文件，用于打开数据库和检索数据

class Entry {

    let image : String!
    let heading : String!
    let title : String!
    let description : String!
    public init(image : String, heading : String, title : String, desc : String) {
        self.heading = heading
        self.image = image
        self.title = title
        self.description = desc
    }
}


class ChapterData {

    var paDB : COpaquePointer = nil;
    var selectStatement : COpaquePointer = nil;
    var sqlString : String = "";

    var newEntryArray : Array<Entry> = [];
    var entryV : Entry;

    init(newEntryArray : Array<Entry>, entryV : Entry, paDB55 : COpaquePointer, selectStatement : COpaquePointer, sqlString : String){
        self.newEntryArray = newEntryArray
        self.entryV = entryV
        self.paDB = paDB55
        self.selectStatement = selectStatement
        self.sqlString = sqlString
    }

    func openDB() {
        var paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as! String
        var docsDir = paths.stringByAppendingPathComponent("pa55.sqlite")


        if (sqlite3_open(docsDir, &paDB) == SQLITE_OK) {
            println("success open database")
        }
        else {
            println("failed to open database")
        }
    }

    func prepareStartment() -> Array<Entry>   {
        sqlString = "SELECT * FROM Chapter ORDER BY CID ASC"
        var cSql = sqlString.cStringUsingEncoding(NSUTF8StringEncoding)
        sqlite3_prepare_v2(paDB, cSql!, -1, &selectStatement, nil)

        println("startment start")

        while (sqlite3_step(selectStatement) == SQLITE_ROW) {

            let image_buf = sqlite3_column_text(selectStatement, 3)
            var image = String.fromCString(UnsafePointer<CChar>(image_buf))

            let heading_buf = sqlite3_column_text(selectStatement, 1)
            var heading = String.fromCString(UnsafePointer<CChar>(heading_buf))

            let title_buf = sqlite3_column_text(selectStatement, 2)
            var title = String.fromCString(UnsafePointer<CChar>(title_buf))

            let desc_buf = sqlite3_column_text(selectStatement, 4)
            var description = String.fromCString(UnsafePointer<CChar>(desc_buf))

            entryV = Entry(image: image!, heading: heading!, title: title!, desc: description!)
            newEntryArray.append(entryV)
        }
        println("select statement successful executed")
        return newEntryArray
    }

}
4

4 回答 4

6

init混乱是 ObjC <-> Swift 桥接的一个已知限制。

解决此问题的一种方法是委托给super' 的init(nibName:bundle:)初始化程序。

class PlacesTableViewController: UITableViewController { 

    var chapterdata: [Entry]
    var chpData: ChapterData?
    var ety: Entry
    var pa55DB: COpaquePointer
    var selectStatement: COpaquePointer
    var sqlString: String


    init(pa55DB: COpaquePointer, selectStatement: COpaquePointer, chapterdata: [Entry], ety: Entry, sqlString: String) {
        self.pa55DB = pa55DB
        self.selectStatement = selectStatement
        self.chapterdata = chapterdata
        self.ety = ety
        self.sqlString = sqlString

        super.init(nibName: nil, bundle: nil)
    }


    required init(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    // …
}
于 2015-05-19T14:38:15.770 回答
2

看看这是否能解决您的问题：

override init(style: UITableViewStyle) {
    super.init(style: style)
}

init(pa55DB : COpaquePointer,selectStatement : COpaquePointer, chapterdata : Array<Entry>, ety : Entry, sqlString : String) {
    super.init(style: UITableView.Style.plain)
    self.pa55DB = pa55DB
    self.selectStatement = selectStatement
    self.chapterdata = chapterdata
    self.ety = ety
    self.sqlString = sqlString

}

UITableView 类参考

来自 Swift 编程语言指南：

指定初始化器是类的主要初始化器。指定的初始化程序完全初始化该类引入的所有属性，并调用适当的超类初始化程序以继续沿超类链的初始化过程。

[阅读更多]

更新：

上面的代码实际上解决了您指定的初始化程序的问题。您现在需要正确初始化您的 self.ety 属性。

于 2015-05-19T03:21:54.427 回答
0

也许尝试这样的事情：

class PlacesTableViewController: UITableViewController { 

   var chapterdata: [Entry]
   var chpData: ChapterData?
   var ety: Entry
   var pa55DB: COpaquePointer
   var selectStatement: COpaquePointer
   var sqlString: String


   convenience init(pa55DB: COpaquePointer, selectStatement: COpaquePointer, chapterdata: [Entry], ety: Entry, sqlString: String) {
       self.init()

       self.pa55DB = pa55DB
       self.selectStatement = selectStatement
       self.chapterdata = chapterdata
       self.ety = ety
       self.sqlString = sqlString

   }

   required init(coder aDecoder: NSCoder) {
       super.init(coder: aDecoder)
   }

   // …
}
于 2015-09-03T19:35:51.103 回答
-1

UITableViewController 对于高级用例没有什么好处。您总是可以子类化UIViewController并在其中放置一个UITableView属性，就像这样：

class PlacesTableViewController: UIViewController {

    let tableView = UITableView(frame: CGRectZero, style: .Plain)

    override func loadView() {
        view = tableView
    }

    // Custom designated initializer
    init(pa55DB : COpaquePointer,selectStatement : COpaquePointer, chapterdata : Array<Entry>, ety : Entry, sqlString : String) {
        // setting up these properties
        super.init(nibName: nil, bundle: nil)  // designated initializer of the superclass 'UIViewController'"
    }
}

它像UITableViewController.

其他实用程序UITableViewController提供，如refreshControl您也可以为自己设置一个，也可以根据您的需要或根据您的需要clearsSelectionOnViewWillAppear实现类似机制。viewWillAppear()didSelectRowAtIndexPath

于 2015-12-31T08:17:23.820 回答