objective-c - Swift 中 NSDictionary 函数的问题

Question

我有以下 imageMap，它在名为 WXCondition 的 Class 中返回 NSDictionary:

+ (NSDictionary *)imageMap {
    // 1
    static NSDictionary *_imageMap = nil;
    if (! _imageMap) {
        // 2
        _imageMap = @{
          @"01d" : @"weather-clear",
          @"02d" : @"weather-few",
          @"03d" : @"weather-few",
          @"04d" : @"weather-broken",
          @"09d" : @"weather-shower",
          @"10d" : @"weather-rain",
          @"11d" : @"weather-tstorm",
          @"13d" : @"weather-snow",
          @"50d" : @"weather-mist",
          @"01n" : @"weather-moon",
          @"02n" : @"weather-few-night",
          @"03n" : @"weather-few-night",
          @"04n" : @"weather-broken",
          @"09n" : @"weather-shower",
          @"10n" : @"weather-rain-night",
          @"11n" : @"weather-tstorm",
          @"13n" : @"weather-snow",
          @"50n" : @"weather-mist",
      };
    }
    return _imageMap;
}

然后我有以下返回 imageMap 方法的方法:

- (NSString *)imageName {
    return [WXCondition imageMap][self.icon];
}

我正在尝试将这些方法转换为 Swift，到目前为止我有以下内容:

func JSONKeyPathsByPropertyKey() -> NSDictionary {
    return {
        "date": "dt",
        "locationName": "name",
        "humidity": "main.humidity",
        "temperature": "main.temp",
        "tempHigh": "main.temp_max",
        "tempLow": "main.temp_min",
        "sunrise": "sys.sunrise",
        "sunset": "sys.sunset",
        "conditionDescription": "weather.description",
        "condition": "weather.main",
        "icon": "weather.icon",
        "windBearing": "wind.deg",
        "windSpeed": "wind.speed"
    }
}

func imageName() -> NSString {
    return "" //[WXCondition imageMap][self.icon];
}

不太确定如何正确返回 NSDictionary。

Answer 1

+ 方法称为类 方法。在 Swift 中，您使用关键字 class。如果你需要一个 NSDictionary，你可以创建一个普通的字典，然后只使用 as 关键字(你也可以将它桥接到 objective-c ，但这更明确)。所以这就是你最终会得到的:

class func blah() -> NSDictionary {
    return [
        "date": "dt",
        "locationName": "name"
        // ...
    ] as NSDictionary
}

你的第二个函数(虽然我没有看到太多关于它的信息)可能只是被修改成类似的东西:return WXCondition.imageMap()[self.icon](你可能需要include as NSString 取决于信息的来源和你试图用它做什么)