blocks|key|227306|text|为什么不使用真正的泛型方法GetDataElement<T>+where+T+:+DataElement呢？C#中不支持通用索引器。为什么你认为在这种情况下，索引器比方法更好？|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|227307|entityMap^0|D|13|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|$]]

Why not use a real generic method <code>GetDataElement&lt;T&gt; where T : DataElement</code> instead? Generic indexers are not supported in C#. Why do you think in this case an indexer is better than a method?

blocks|key|227346|text|最好的选择是使用泛型方法(而不是索引器)，或者让您的类成为泛型(在这种情况下，索引器将绑定到类泛型类型)。您所描述的通用索引器在C#中是不允许的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|227347|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

The best options are to either use a generic method (instead of an indexer), or to have your class be generic (in which case, the indexer would be tied to the class generic type). A generic indexer as you've described is not allowed in C#.

blocks|key|1989694|text|这对你来说是个案例吗？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1989695|public+class+DicomDictionary<TElement>+
{
++++++++Dictionary<int,+TElement>+myElements+=+new+Dictionary<int,+TElement>();
++++++++public+TElement+this[int+DataElementTag]+++
++++++++{+++++
++++++++++++++get+++++
++++++++++++++{+++++++
+++++++++++++++++return+myElements[int];+++++
++++++++++++++}+++
++++++++}+
}|code-block|syntax|javascript|1989696|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Is it a case for you?

<pre><code>public class DicomDictionary&lt;TElement&gt; 
{
 Dictionary&lt;int, TElement&gt; myElements = new Dictionary&lt;int, TElement&gt;();
 public TElement this[int DataElementTag] 
 { 
 get 
 { 
 return myElements[int]; 
 } 
 } 
}
</code></pre>

blocks|key|3603683|text|附加到sll的答案是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3603684|public+class+Acessor<TKey,+TValue>
++++where+TKey+:+IComparable
++++where+TValue+:+class
{
++++Dictionary<TKey,+TValue>+myElements+=+new+Dictionary<TKey,+TValue>();

++++public+TValue+this[TKey+key]
++++{
++++++++get
++++++++{
++++++++++++return+myElements[key];
++++++++}
++++++++set
++++++++{
++++++++++++myElements.Add(key,+value);
++++++++}
++++}
}|code-block|syntax|javascript|3603685|或者在不更改类签名的情况下：|3603686|+public+class+Acessor
{
++++Dictionary<string,+object>+myElements+=+new+Dictionary<string,+object>();

++++public+object+this[string+key]
++++{
++++++++get
++++++++{
++++++++++++return+myElements[key];
++++++++}
++++++++set
++++++++{
++++++++++++myElements.Add(key,+value);
++++++++}
++++}
}|3603687|并创建一个方法来解析泛型类型：|3603688|public+T+Get<T>(string+key)
++++++++where+T+:+class
++++{
++++++++return+(T)Convert.ChangeType(acessor[key],+typeof(T));
++++}|3603689|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

Append for sll answer is:

<pre><code>public class Acessor&lt;TKey, TValue&gt;
 where TKey : IComparable
 where TValue : class
{
 Dictionary&lt;TKey, TValue&gt; myElements = new Dictionary&lt;TKey, TValue&gt;();

 public TValue this[TKey key]
 {
 get
 {
 return myElements[key];
 }
 set
 {
 myElements.Add(key, value);
 }
 }
}
</code></pre>

Or without change the class signature:

<pre><code> public class Acessor
{
 Dictionary&lt;string, object&gt; myElements = new Dictionary&lt;string, object&gt;();

 public object this[string key]
 {
 get
 {
 return myElements[key];
 }
 set
 {
 myElements.Add(key, value);
 }
 }
}
</code></pre>

And create a method to parse for the generic type:

<pre><code>public T Get&lt;T&gt;(string key)
 where T : class
 {
 return (T)Convert.ChangeType(acessor[key], typeof(T));
 }
</code></pre>

I have a DICOM dictionary that contains a set of objects all deriving from DataElement.
The dictionary has an int as a key, and the DataElement as property.
My DICOM dictionary contains a this[] property where I can access the DataElement, like this:

<pre><code>public class DicomDictionary
{
 Dictionary&lt;int, DataElement&gt; myElements = new Dictionary&lt;int, DataElement&gt;();
 .
 .
 public DataElement this[int DataElementTag]
 {
 get
 {
 return myElements[int];
 }
 }
}
</code></pre>

A problem now is that I have different DataElement types all deriving from DataElement, like DataElementSQ, DataElementOB and so on. What I wanted to do now is the following to make writing in C# a little bit easier:

<pre><code> public T this&lt;T&gt;[int DataElementTag] where T : DataElement
 {
 get
 {
 return myElements[int];
 }
 }
</code></pre>

But this is not really possible. Is there something I have missed? Of course I could do it with Getter method, but it would be much nicer to have it this way.

Can I have a generic this[] property?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我有一个DICOM字典，其中包含一组对象，这些对象都是从DataElement派生的。字典有一个int作为键，DataElement作为属性。我的DICOM字典包含一个可以访问DataElement的this[]属性，如下所示：public class DicomDictionary{ Dictionary<int,...

问我能有一个泛型的this[]属性吗？
EN

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问我能有一个泛型的this[]属性吗？EN