C#Foreach循环哈希表问题

Question

我有一些代码填充哈希表,其中一个问题作为键,一个答案的arraylist作为值.

我想从哈希表中打印出这些值,以便在哈希表中显示每个问题的问题和相应的解决方案.

我知道我已经用foreach循环做了一些完全愚蠢的事情来打印出哈希表的内容,但是我已经编写了好几个小时的编码,我想不出打印我的嵌套arraylist的逻辑.

非常感谢.

这是代码:

//Hashtable Declaration
static Hashtable sourceList = new Hashtable();    

//Class For Storing Question Information
public class QuestionAnswerClass
{
    public string simonQuestion;
    public ArrayList simonAnswer = new ArrayList();
}

//Foreach loop which populates a hashtable with results from
//a linq query that i need to print out.
foreach (var v in linqQueryResult)
        {
            Debug.WriteLine(v.question);
            newques.simonQuestion = v.question;
            //Debug.WriteLine(v.qtype);
            //newques.simonQType = v.qtype;

            foreach (var s in v.solution)
            {
                Debug.WriteLine(s.Answer);
                newques.simonAnswer.Add(s.Answer);
            }
        }          

        sourceList.Add(qTextInput,newques);

//foreach loop to print out contents of hashtable
foreach (string key in sourceList.Keys)
        {
            foreach(string value in sourceList.Values)
            {
                Debug.WriteLine(key);
                Debug.WriteLine(sourceList.Values.ToString());
            }
        }

Answer 1

当您使用LINQ时,您显然不受框架1.1的限制,因此您不应该使用HashTable和ArrayList类.您应该使用严格类型的泛型Dictionary和List类.

您不需要课程来保持问题和答案Dictionary.该类只是一个没有实际用途的额外容器.

//Dictionary declaration
static Dictionary<string, List<string>> sourceList = new Dictionary<string, List<string>>();

//Foreach loop which populates a Dictionary with results from
//a linq query that i need to print out.
foreach (var v in linqQueryResult) {
   List<string> answers = v.solution.Select(s => s.Answer).ToList();
   sourceList.Add(v.question, answers);
}          

//foreach loop to print out contents of Dictionary
foreach (KeyValuePair<string, List<string>> item in sourceList) {
   Debug.WriteLine(item.Key);
   foreach(string answer in item.Value) {
      Debug.WriteLine(answer);
   }
}

如果由于其他原因需要课程,那可能如下所示.

(请注意,问题字符串在类中都被引用并在字典中用作键,但字典键实际上并未用于此代码中的任何内容.)

//Class For Storing Question Information
public class QuestionAnswers {

   public string Question { get; private set; }
   public List<string> Answers { get; private set; }

   public QuestionAnswers(string question, IEnumerable<string> answers) {
      Question = question;
      Answers = new List<string>(answers);
   }

}

//Dictionary declaration
static Dictionary<string, QuestionAnswers> sourceList = new Dictionary<string, QuestionAnswers>();

//Foreach loop which populates a Dictionary with results from
//a linq query that i need to print out.
foreach (var v in linqQueryResult) {
   QuestionAnswers qa = new QuestionAnswers(v.question, v.solution.Select(s => s.Answer));
   sourceList.Add(qa.Question, qa);
}          

//foreach loop to print out contents of Dictionary
foreach (QustionAnswers qa in sourceList.Values) {
   Debug.WriteLine(qa.Question);
   foreach(string answer in qa.Answers) {
      Debug.WriteLine(answer);
   }
}