Question

我有两个哈希表。我想基于密钥比较两个哈希表的值。我想在循环中执行此操作，如果找到匹配则要执行字符串构建操作。但问题是我不知道在循环中比较它们的任何机制。请指导我...... 以下是我要比较的哈希表

       HashTable OldTable= new HashTable();

        OldTable.Add("Date of Event", OCEFData.EventDate);
            OldTable.Add("Angina Status", OCEFData.AnginaStatusValue);
            OldTable.Add("Please indicate the body system involved (tick all that apply)",strBodySystem.ToString());
            OldTable.Add("If Unstable Angina, define Braunswald Classification", OCEFData.UnstableAnginaValue);
            OldTable.Add("If Stable Angina", OCEFData.StableAnginaValue);
            OldTable.Add("Details of method of Documentation of Angina", OCEFData.AnginaDocDetails);
            OldTable.Add("INFORM TO SPONSOR", (OCEFData.IsInformed)?"Yes":"No");
            OldTable.Add("DATE OF INFORMATION TO SPONSOR ", OCEFData.SponsorDate);
            OldTable.Add("DATE OF INFORMATION TO INSTITUTIONAL ETHICS COMMITTEE", OCEFData.EthicsCommitteeDate);
            OldTable.Add("DATE OF INFORMATION TO LICENSING AUTHORITY", OCEFData.LicensingAuthority);



       HashTable NewTable= new HashTable();

       NewTable.Add("Date of Event", OCEFData.EventDate);
        NewTable.Add("Angina Status", OCEFData.AnginaStatusValue);
        NewTable.Add("Please indicate the body system involved (tick all that apply)", strBodySystem.ToString());
        NewTable.Add("If Unstable Angina, define Braunswald Classification", OCEFData.UnstableAnginaValue);
        NewTable.Add("If Stable Angina", OCEFData.StableAnginaValue);
        NewTable.Add("Details of method of Documentation of Angina", OCEFData.AnginaDocDetails);
        NewTable.Add("INFORM TO SPONSOR", (OCEFData.IsInformed)?"Yes":"No");
        NewTable.Add("DATE OF INFORMATION TO SPONSOR ", OCEFData.SponsorDate);
        NewTable.Add("DATE OF INFORMATION TO INSTITUTIONAL ETHICS COMMITTEE", OCEFData.EthicsCommitteeDate);
        NewTable.Add("DATE OF INFORMATION TO LICENSING AUTHORITY", OCEFData.LicensingAuthority);

Answer 1

这是你想要的吗？

Hashtable OldTable = new Hashtable();
Hashtable NewTable = new Hashtable();

        foreach (DictionaryEntry entry in OldTable)
        {
            if(NewTable.ContainsKey(entry.Key))
            {
                //Do something?
            }
        }

Answer 2

您可以使用Linq交叉键，在两个表中为您提供键集合吗？

var combinedKeys=OldTable.Keys.Cast<string>().Intersect(NewTable.Keys.Cast<string>())

然后，您可以迭代键或使用Linq Select或Agregate语句来获取收集结果。

修改

由于HashTable没有强类型，Keys没有为您提供IEnumerable，因此调用Cast<string>()获取IEnumerable<string>

如果您使用的是强类型Dictionary<string,string>，则不需要Cast<string>()部分。

Answer 3

假设您正在尝试匹配两个HashTable中的键...您可以这样做

 foreach (string key in oldtable.Keys)
    {
        if (newtable.Contains(key))
        {
            // do your work;
        }
        else
        {
            // do your work;         
       }
    }

Answer 4

首先 - 使用键入的Dictionary<TKey, TValue>而不是Hashtable，下面是值为string类型的示例，这可以很容易地将string更改为您的自定义类型（我相信enum或已经是字符串常量。）

IDictionary<string, string> map1 = new Dictionary<string, string>
                                        {
                                            {"A", "M1-A"},
                                            {"B", "M1-B"},
                                            {"C", "M1-C"}
                                        };

IDictionary<string, string> map2 = new Dictionary<string, string>
                                        {
                                            {"A", "M2-A"},
                                            {"B", "M2-B"},
                                            {"D", "M2-D"}
                                        };

.NET 3.5及更高版本：使用LINQ Intersect()

var items = map1.Keys.Intersect(map2.Keys)
                     .Select(k => map1[k] + " / " + map2[k])
                     .ToList();

＆lt; .NET 3.5

IList<string> results = new List<string>();
foreach (var key in map1.Keys)
{
    if (map2.ContainsKey(key))
    {
        results.Add(map1[key] + " / " + map2[key]);
    }
}

OUTPUT:
M1-A / M2-A
M1-B / M2-B

比较循环中两个哈希表的值

4 个答案: