ios Swift 2.0：没有更多上下文的表达式类型是不明确的？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/32663364/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Swift 2.0: Type of Expression is ambiguous without more context?
提问by lernerbot
The following used to work in Swift 1.2:
以下用于在 Swift 1.2 中工作：
var recordSettings = [
AVFormatIDKey: kAudioFormatMPEG4AAC,
AVEncoderAudioQualityKey : AVAudioQuality.Max.rawValue,
AVEncoderBitRateKey : 320000,
AVNumberOfChannelsKey: 2,
AVSampleRateKey : 44100.0]
Now, it gives the error:
现在，它给出了错误：
"Type expression is ambiguous without more context".
“没有更多上下文，类型表达式是不明确的”。
采纳答案by Stephan
To comply to the required [String : AnyObject]format required by recordSettingsparameter; In addition to @Unheilig's answer, you'll need to convert your intsand floatsto NSNumber:
符合参数要求的[String : AnyObject]格式recordSettings；除了@Unheilig 的回答之外，您还需要将您的intsand转换floats为NSNumber：
let recordSettings : [String : AnyObject] =
[
AVFormatIDKey: NSNumber(unsignedInt: kAudioFormatMPEG4AAC),
AVEncoderAudioQualityKey : AVAudioQuality.Max.rawValue as NSNumber,
AVEncoderBitRateKey : 320000 as NSNumber,
AVNumberOfChannelsKey: 2 as NSNumber,
AVSampleRateKey : 44100.0 as NSNumber
]
回答by Unheilig
You could give the compiler more information:
您可以为编译器提供更多信息：
let recordSettings : [String : Any] =
[
AVFormatIDKey: kAudioFormatMPEG4AAC,
AVEncoderAudioQualityKey : AVAudioQuality.Max.rawValue,
AVEncoderBitRateKey : 320000,
AVNumberOfChannelsKey: 2,
AVSampleRateKey : 44100.0
]
回答by rghome
I also got this error message trying to initialise an array of optionals with nil:
我还收到此错误消息，试图用 nil 初始化一组可选值：
var eggs : [Egg] = Array<Egg>(count: 10, repeatedValue: nil)
Expression Type 'Array<Egg>' is ambiguous without more context.
表达式类型 'Array<Egg>' 在没有更多上下文的情况下是不明确的。
Changing [Egg]to [Egg?]fixed the error.
更改[Egg]以[Egg?]修复错误。
