Conversion String to NSDate - Fatal error: Unexpectedly found nil while unwrapping an Optional value

Conversion String to NSDate - Fatal error: Unexpectedly found nil while unwrapping an Optional value

怎么了? 相同的代码适用于其他 类。当我将字符串转换为 nsdate 时,模拟器崩溃了。

let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = "EEE, dd/MM/yyyy (HH:mm)"
        
        
        //ordino il file 
        var dataminima = dateFormatter.date(from: "lun, 01/01/2010 (01:01)")
        var datamassima = dateFormatter.date(from: "lun, 01/01/2010 (01:01)")
        
        var indice = 0
        var indiceminimo = 1
        
        var indice1 = 0
        
        for data in arraycomplessivo {
            let validData = data as! NSDictionary
            let dataestratta = validData["data"]
            print(dataestratta as! String)
            
            //converto da stringa a NSDate - that's the error
            let dataconvertita = dateFormatter.date(from:dataestratta as! String)!
            
            //print(dataminima!)
            print(dataconvertita)

// dataestratta 是:gio,10/06/2021 (12:00)

error in console

模拟器中的语言环境不一定与您的设备或 Mac 中的语言环境相同。

由于字符串日期格式显然是意大利语,因此添加固定语言环境

dateFormatter.locale = Locale(identifier: "it_IT")
dateFormatter.dateFormat = "EEE, dd/MM/yyyy (HH:mm)"