ios - NSJSON序列化: unexpectedly found nil while unwrapping an Optional value

Question

通常情况下，以下代码可以正常工作，但有时我认为，JSON 返回 nil 并遇到 fatal error 。如果数据为零我该如何处理。

我在以下行遇到 EXC_BAD_INSTRUCTION 错误:

let profileJsonArray = try NSJSONSerialization.JSONObjectWithData(data!, options: .MutableContainers) as? NSArray

感谢您的帮助。

do {
        let profileJsonArray = try NSJSONSerialization.JSONObjectWithData(data!, options: .MutableContainers) as? NSArray

        if let parseJSONArray = profileJsonArray {                
            self.myProfileinfo = parseJSONArray

                    let name: String? = self.myProfileinfo[0].valueForKey("fullname") as? String
                    let messsage: String? = self.myProfileinfo[0].valueForKey("message") as? String
                    let infourl: String! = self.myProfileinfo[0].valueForKey("thumb") as? String
                    let prourl: String! = self.myProfileinfo[0].valueForKey("prothumb") as? String
                    let email: String? = self.myProfileinfo[0].valueForKey("email") as? String ...

Answer 1

读取网络响应时，应先检查是否有错误。

NSSession 例如:

let task = session.dataTaskWithRequest(request, completionHandler: {data, response, error -> Void in
    if error {
        // Deal with error, e.g.
        print(error)
    }
    else {
        do {
            // Use data or response
            let profileJsonArray = try NSJSONSerialization.JSONObjectWithData(data!, options: .MutableContainers) as? NSArray
            // ....
        }
        catch {
            // Deal with error
        }
    }
})
task.resume();