Question

我刚接触过Swift，但不知道这意味着什么。在下面的代码行中，我有＆＃34;表达式列表中的预期表达式＆＃34;在参数[String]之后。同时它正在寻找＆＃34;预期＆＃39;，＆＃39;分隔器。我相信这些是相关的。

AppDelegate.submitLacunaRequest(module: "empire", method: "login", parameters[String]:["myuserid", "mypassword", "mykey"]) {

            responseObject, error in

            // some network error or programming error

            if error != nil {
                println("error = \(error)")
                println("responseObject = \(responseObject)")
                return
            }

            // network request ok, now see if login was successful

            if let responseDictionary = responseObject as? NSDictionary {
                if let errorDictionary = responseDictionary["error"] as? NSDictionary {
                    println("error logging in (bad userid/password?): \(errorDictionary)")
                } else if let resultDictionary = responseDictionary["result"] as? NSDictionary {
                    println("successfully logged in, refer to resultDictionary for details: \(resultDictionary)")
                } else {
                    println("we should never get here")
                    println("responseObject = \(responseObject)")
                }
            }
        }

以下是AppDelegate的相关代码

public func submitLacunaRequest (#module: String, method: String, parameters: AnyObject, completion: (responseObject: AnyObject!, error: NSError!) -> (Void)) -> NSURLSessionTask? {

    let session = NSURLSession.sharedSession()
    let url = NSURL(string: "https://us1.lacunaexpanse.com")?.URLByAppendingPathComponent(module)
    let request = NSMutableURLRequest(URL: url!)
    request.HTTPMethod = "POST"
    request.setValue("application/json-rpc", forHTTPHeaderField: "Content-Type")


    let requestDictionary = [
        "jsonrpc" : "2.0",
        "id"      : 1,
        "method"  : "login",
        "params"  : ["myuserid", "mypassword", "mykey"]
    ]

    var error: NSError?
    let requestBody = NSJSONSerialization.dataWithJSONObject(requestDictionary, options: nil, error: &error)
    if requestBody == nil {
        completion(responseObject: nil, error: error)
        return nil
    }

    request.HTTPBody = requestBody

    let task = session.dataTaskWithRequest(request) {
        data, response, error in

        // handle fundamental network errors (e.g. no connectivity)

        if error != nil {
            completion(responseObject: data, error: error)
            return
        }

        // parse the JSON response

        var parseError: NSError?
        let responseObject = NSJSONSerialization.JSONObjectWithData(data, options: nil, error: &parseError) as? NSDictionary

        if responseObject == nil {

            // because it's not JSON, let's convert it to a string when we report completion (likely HTML or text)

            let responseString = NSString(data: data, encoding: NSUTF8StringEncoding) as String
            completion(responseObject: responseString, error: parseError)
            return
        }

        completion(responseObject: responseObject, error: nil)
    }
    task.resume()

    return task
}

Answer 1

调用函数时，您正在使用参数的外部参数名称，但函数声明中未定义外部参数。只需这样使用它。

submitLacunaRequest(module: "empire", "login", ["myuserid", "mypassword", "mykey"]) {

Answer 2

您正在错误地调用该函数。您不需要[String]参数中的parameters ...

AppDelegate.submitLacunaRequest(module: "empire", method: "login", parameters: ["myuserid", "mypassword", "mykey"]) {
    ...
}

Answer 3

我将函数参数称为protocol。如果我想像往常一样尝试使用此属性，我会注意到它用粉红色表示为关键字，然后将其重命名。

相反，我在这样的字符串中使用了此属性，但编译器没有任何提示：

func configure(_ protocol: Protocol, host:String, port:String) {
    urlString = "\(protocol)://\(host):\(port)"
}

我花了5分钟的时间被这个错误弄糊涂了，但是后来我发现了。 问题出在参数名称上。

我不想重命名参数，所以我最终这样写了：

urlString = "\(`protocol`)://\(host):\(port)"

Swift - 表达式列表中的预期表达式

3 个答案: