将json调用语法从Objective-C转换为Swift的正确方法是啥?
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【中文标题】将json调用语法从Objective-C转换为Swift的正确方法是啥?【英文标题】:What is the right way to convert json call syntax from Objective-C to Swift?将json调用语法从Objective-C转换为Swift的正确方法是什么? 【发布时间】:2015-11-02 04:04:03 【问题描述】:我正在将 ViewController 从 Objective-C 更新到 Swift,并遇到了几个错误,我的原始代码是:
/* Line 161 read: NSString *dateString = [NSString stringWithFormat:@"%i-%i", start.month, start.day];
*/ This is from Objective-c file to call Holiday.json file
NSString *dateString = [NSString, stringWithFormat;@"%li-%li", (long)start.month, (long)start.day];
NSString *filePath = [[NSBundle mainBundle] pathForResource:@"Holidays" ofType:@"json"];
NSString *holidayJSON = [[NSString alloc] initWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:NULL];
if (holidayJSON)
NSData *jsonData = [holidayJSON dataUsingEncoding:NSUTF8StringEncoding];
NSDictionary *results = [NSJSONSerialization JSONObjectWithData:jsonData options:0 error:nil];
NSDictionary *holiday = [results objectForKey:dateString];
NSDictionary *titleDescription = [holiday objectForKey:@"holidays"];
NSLog(@"holiday %@", titleDescription);
NSString *title = [[titleDescription valueForKey:@"title"]objectAtIndex:0];
NSString *description = [[titleDescription valueForKey:@"description"]objectAtIndex:0];
NSLog(@"title: %@, description: %@", title, description);
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:title message:description delegate:nil cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil];
[alertView show];
NSLog( @"Selected %ld/%ld - %ld/%ld", (long)range.startDay.day, (long)range.startDay.month, (long)range.endDay.day, (long)range.endDay.month);
else
NSLog( @"No selection" );
在尝试将其更改为 Swift 时,我遇到了几个错误:
// have calendar present a holiday from the JSON file for each day
let filePath: String = NSBundle.mainBundle().pathForResource("Holiday", ofType: "json") as String!
let jsonData = NSData(contentsOfFile:filePath) as NSData!
let dateString = ["%li-%li",DayView.monthstart.day] as NSString!
var holidayJSON: String = NSString(contentsOfFile: filePath, encoding: NSUTF8StringEncoding, error: nil)
if holidayJSON
var jsonData: NSData = holidayJSON.dataUsingEncoding(NSUTF8StringEncoding)
var results: [NSObject : AnyObject] = NSJSONSerialization.JSONObjectWithData(jsonData, options: 0, error: nil)
var holiday: [NSObject : AnyObject] = results[dateString]
var titleDescription: [NSObject : AnyObject] = holiday["holidays"]
NSLog("holiday %@", titleDescription)
var title: String = titleDescription.valueForKey("title").objectAtIndex(0)
var description: String = titleDescription.valueForKey("description").objectAtIndex(0)
NSLog("title: %@, description: %@", title, description)
var alertView: UIAlertView = UIAlertView(title: title, message: description, delegate: nil, cancelButtonTitle: "Ok", otherButtonTitles: nilnil)
alertView.show()
NSLog("Selected %ld/%ld - %ld/%ld", range.startDay.day, range.startDay.month, range.endDay.day, range.endDay.month)
【问题讨论】:
您遇到了哪些错误以及发生在哪些行上? 我建议你不要转换语法。使用 Swift 特性进行编码。例如,对于 JSON 解析,您可以尝试 SwiftyJSon。 谢谢,我现在主要转换了大部分。我只收到警告“UIAlertView 在 ios9 中已弃用:UIAletView 已弃用”但它仍然无法正常工作,因为我需要找到正确的函数来调用日期。 【参考方案1】:我对coding/***/etc..etc还是很陌生...所以当我提出这个问题时,我正在寻找关于如何解决问题的其他想法,我遇到了一个视频说我可以使用桥接在 swift 项目中使用 Objective-c 的头文件。这是我当时没有想到的一种解决方案。但我能够从更有经验的人那里获得一些帮助,这是一个不会出现错误的 swift 版本:
`// Line 161 read: NSString *dateString = [NSString stringWithFormat:@"%i-%i", start.month, start.day];
// This is from Objective-c file to call Holiday.json file
func holidayForDate(date:CVDate)
//let cal = NSCalendar.currentCalendar()
// let components = cal.components([.Month, .Day], fromDate: date)
let dateString = "\(date.month)-\(date.day)"
guard let path : String = NSBundle.mainBundle().pathForResource("Holiday", ofType: "json") else
// TODO error handling?
return
guard let jsonData = NSData(contentsOfFile: path) else
// TODO error handling?
return
do
guard let dict:[String:AnyObject] = try NSJSONSerialization.JSONObjectWithData(jsonData, options: []) as? [String : AnyObject] else
// TODO error handling
return
let holidays:[[String:String]] = dict[dateString] as! [[String:String]]
if let holiday = holidays.first
let title = holiday["title"]
let description = holiday["description"]
UIAlertView(title: title, message: description, delegate: nil, cancelButtonTitle: "OK").show()
catch
NSLog("\(error)")
`
【讨论】:
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