blocks|key|49794|text|从SWIFT2.0开始，Dictionary的values属性现在返回LazyMapCollection而不是LazyBidirectionalCollection。Array类型知道如何使用此抽象集合类型初始化自身：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|49795|let+colors+=+Array(colorsForColorSchemes.values)|code-block|syntax|javascript|49796|Swift的类型推断已经知道这些值是UIColor对象，所以不需要类型转换，这很好！|49797|entityMap^0|C|A|N|6|Z|H|1J|R|2B|5|0|0|I|7|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]|$9|T|A|U|B|C]|$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|Z|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|10|8|@$9|11|A|12|B|C]]|D|@]|E|$]]|$1|M|3|-4|5|6|7|13|8|@]|D|@]|E|$]]]|N|$]]

As of Swift 2.0, <code>Dictionary</code>’s <code>values</code> property now returns a <code>LazyMapCollection</code> instead of a <code>LazyBidirectionalCollection</code>. The <code>Array</code> type knows how to initialise itself using this abstract collection type:

<pre><code>let colors = Array(colorsForColorSchemes.values)
</code></pre>

Swift's type inference already knows that these values are <code>UIColor</code> objects, so no type casting is required, which is nice!

blocks|key|49825|text|您可以在LazyMapCollection上创建扩展模块|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|49826|public+extension+LazyMapCollection++{

++++func+toArray()+->+[Element]{
++++++++return+Array(self)
++++}
}|code-block|syntax|javascript|49827|colorsForColorSchemes.values.toArray()或colorsForColorSchemes.keys.toArray()|49828|entityMap^0|4|H|0|0|0|12|13|10|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]]|D|@]|E|$]]|$1|M|3|-4|5|6|7|X|8|@]|D|@]|E|$]]]|N|$]]

you can create an extension on <code>LazyMapCollection</code>

<pre><code>public extension LazyMapCollection {

 func toArray() -&gt; [Element]{
 return Array(self)
 }
}
</code></pre>

<code>colorsForColorSchemes.values.toArray()</code> or <code>colorsForColorSchemes.keys.toArray()</code>

blocks|key|4556443|text|使用colorsForColorScheme.map({$0.value})|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4556444|entityMap^0|2|10|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

Use <code>colorsForColorScheme.map({$0.value})</code>

blocks|key|49892|text|我发现这是Swift+5中最有用的：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|49893|colorsForColorSchemes.allValues|offset|length|style|CODE|49894|请参阅docs+-+https://developer.apple.com/documentation/foundation/nsdictionary/1408915-allvalues|49895|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.apple.com/documentation/foundation/nsdictionary/1408915-allvalues^0|0|0|V|0|A|2B|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|S|8|@$D|T|E|U|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|V|8|@]|9|@$D|W|E|X|1|Y]]|A|$]]|$1|J|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|K|$L|$5|M|N|O|A|$P|Q]]]]

I've found this to be the most useful in Swift 5:

<code>colorsForColorSchemes.allValues</code> 

See docs - <a href="https://developer.apple.com/documentation/foundation/nsdictionary/1408915-allvalues" rel="nofollow noreferrer">https://developer.apple.com/documentation/foundation/nsdictionary/1408915-allvalues</a>

blocks|key|4556509|text|首先，从下面的语句可以看出，您的变量(字典)名称是colorsForColorScheme|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4556510|var+colorsForColorScheme:+[ColorScheme+:+UIColor]+=+...+|code-block|syntax|javascript|4556511|当您尝试从colorsForColorSchemes字典中获取值时-|4556512|let+colors:+[UIColor]+=+colorsForColorSchemes.values|4556513|这应该会给你一个编译时错误。无论如何，我假设你有一个打字错误，你的字典的名字是colorsForColorSchemes。所以，这就是解决方案-|4556514|如前所述，由于swift中的类型推断属性，您的代码可以推断出从.values函数返回的类型是返回一个UIColor数组。然而，Swift希望是类型安全的，所以当您将值存储在colors数组中时，您需要显式地定义它。对于swift+5和更高版本，现在您只需执行以下操作-|4556515|let+colors+=+[UIColor](colorsForColorSchemes.values)|4556516|entityMap^0|P|K|0|0|5|L|0|0|13|L|0|V|7|2E|6|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|Z|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|10|8|@$9|11|A|12|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|13|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|14|8|@$9|15|A|16|B|C]]|D|@]|E|$]]|$1|Q|3|R|5|6|7|17|8|@$9|18|A|19|B|C]|$9|1A|A|1B|B|C]]|D|@]|E|$]]|$1|S|3|T|5|H|7|1C|8|@]|D|@]|E|$I|J]]|$1|U|3|-4|5|6|7|1D|8|@]|D|@]|E|$]]]|V|$]]

Firstly, from the following statement, it seems that your variable(dictionary) name is <code>colorsForColorScheme</code>

<pre><code>var colorsForColorScheme: [ColorScheme : UIColor] = ... 
</code></pre>

while you are trying to get the values from <code>colorsForColorSchemes</code> dictionary when you did-

<pre><code>let colors: [UIColor] = colorsForColorSchemes.values
</code></pre>

which should give you a compile time error. Anyways I am assuming that you had a typo, and you dictionary's name is <code>colorsForColorSchemes</code>. So, here is the solution-

As mentioned earlier, because of the type inference property in swift, your code can infer that the returned type from the <code>.values</code> function is returning an array of UIColor. However, Swift wants to be type-safe, so when you store the values in the <code>colors</code> array, you need to explicitly define that. For swift 5 and above, now you could just do following-

<pre><code>let colors = [UIColor](colorsForColorSchemes.values)
</code></pre>

blocks|key|49931|text|您也可以使用flatMap|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|49932|let+colors+=+colorsForColorScheme.values.flatMap+{+$0+}|49933|entityMap^0|6|7|0|0|1J|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|P|8|@]|D|@]|E|$]]]|I|$]]

You can also use <code>flatMap</code>:
<code>let colors = colorsForColorScheme.values.flatMap { $0 }</code>

I have a dictionary containing <code>UIColor</code> objects hashed by an enum value, <code>ColorScheme</code>:

<pre><code>var colorsForColorScheme: [ColorScheme : UIColor] = ...
</code></pre>

I would like to be able to extract an array of all the colors (the values) contained by this dictionary. I thought I could use the <code>values</code> property, as is used when iterating over dictionary values (<code>for value in dictionary.values {...}</code>), but this returns an error:

<pre><code>let colors: [UIColor] = colorsForColorSchemes.values
 ~~~~~~~~~~~~~~~~~~~~~^~~~~~~
'LazyBidrectionalCollection&lt;MapCollectionView&lt;Dictionary&lt;ColorScheme, UIColor&gt;, UIColor&gt;&gt;' is not convertible to 'UIColor'
</code></pre>

It seems that rather than returning an <code>Array</code> of values, the <code>values</code> method returns a more abstract collection type. Is there a way to get an <code>Array</code> containing the dictionary's values without extracting them in a <code>for-in</code> loop?

Swift Dictionary: Get values as array

Swift

我有一个字典，其中包含通过枚举值ColorScheme散列的UIColor对象var colorsForColorScheme: [ColorScheme : UIColor] = ...我希望能够提取这个字典包含的所有颜色(值)的数组。我认为我可以使用在迭代字典值(for value in dictionary.va...

问Swift字典:以数组形式获取值
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