1
是否可以按照它們在源文檔中出現的相同順序訪問映射的鍵?即如果我有這個簡單的文檔:我可以依次讀取YamlDotNet映射嗎?
values:
first: something1
second: something2
third: something3
然後我就能夠拿到鑰匙的序列中的原始順序:第一,第二,第三]
是否可以按照它們在源文檔中出現的相同順序訪問映射的鍵?即如果我有這個簡單的文檔:我可以依次讀取YamlDotNet映射嗎?
values:
first: something1
second: something2
third: something3
然後我就能夠拿到鑰匙的序列中的原始順序:第一,第二,第三]
實現此目的的一種方法是使用RepresentationModel
API。它允許獲得YAML文檔的底層結構緊密匹配的表示:
var stream = new YamlStream();
stream.Load(new StringReader(yaml));
var document = stream.Documents.First();
var rootMapping = (YamlMappingNode)document.RootNode;
var valuesMapping = (YamlMappingNode)rootMapping.Children[new YamlScalarNode("values")];
foreach(var tuple in valuesMapping.Children)
{
Console.WriteLine("{0} => {1}", tuple.Key, tuple.Value);
}
這種方法的缺點是,你需要「手動」解析文檔。另一種方法是使用序列化,並使用保留排序的類型。我不知道任何現成的使用實施IDictionary<TKey, TValue>
具有此特徵的,但如果你不關心性能高,它是相當簡單的實現:
// NB: This is a minimal implementation that is intended for demonstration purposes.
// Most of the methods are not implemented, and the ones that are are not efficient.
public class OrderPreservingDictionary<TKey, TValue>
: List<KeyValuePair<TKey, TValue>>, IDictionary<TKey, TValue>
{
public void Add(TKey key, TValue value)
{
Add(new KeyValuePair<TKey, TValue>(key, value));
}
public bool ContainsKey(TKey key)
{
throw new NotImplementedException();
}
public ICollection<TKey> Keys
{
get { throw new NotImplementedException(); }
}
public bool Remove(TKey key)
{
throw new NotImplementedException();
}
public bool TryGetValue(TKey key, out TValue value)
{
throw new NotImplementedException();
}
public ICollection<TValue> Values
{
get { throw new NotImplementedException(); }
}
public TValue this[TKey key]
{
get
{
return this.First(e => e.Key.Equals(key)).Value;
}
set
{
Add(key, value);
}
}
}
一旦你有了這樣的容器,你可以採取Serialization
API的優勢來解析文檔:
var deserializer = new Deserializer();
var result = deserializer.Deserialize<Dictionary<string, OrderPreservingDictionary<string, string>>>(new StringReader(yaml));
foreach(var tuple in result["values"])
{
Console.WriteLine("{0} => {1}", tuple.Key, tuple.Value);
}
只是爲人們尋找這與無意推行有序字典:我覺得這個[TKEY的鍵]被錯誤地執行,你守首先檢查密鑰是否存在,除非你想重複。 另請參閱[this](https://msdn.microsoft.com/pl-pl/library/system.collections.specialized.ordereddictionary(v = vs.110).aspx) – MaLiN2223