c#將字典值組合成新的鍵值對

我有這樣的 ac# 字典：

我需要做的是將字典鍵包含“UPC”的值組合成一個具有組合值的新鍵，因此它的內容如下：{[UPC, 000000000333, 789787878999]}

UPC 可以包含一個或多個值。

我想出了下面的代碼來首先從資訊字典中洗掉可能的重復項

//Remove any duplicates
        List<string> vals = new List<string>();
        Dictionary<string, string> newDict = new Dictionary<string, string>();
        foreach (KeyValuePair<string, string> item in information)
        {
            if (!vals.Contains(item.Value))
            {
                newDict.Add(item.Key, item.Value);
                vals.Add(item.Value);
            }
        }

        StringBuilder sbUPC = new StringBuilder();
        
        var newDictJustUPCs = newDict.Where(kvp => kvp.Key.Contains("UPC"));

newDictJustUPCs 回傳以下內容：

那么我將如何遍歷這些 KeyValuePairs 并為具有鍵“UPC”和兩個值組合的 newDict 創建 KeyValue 對并將其分配給 newDict？

我知道最終答案的一部分將是 newDict.Add("UPC", CombinedUPCValues);

uj5u.com熱心網友回復：

有很多方法可以做到這一點。這里只有一個

給定的

var dict = new Dictionary<string, string>
{
   { "asd", "dfgdfg" },
   { "ghj", "ghj" },
   { "UPC1", "123" },
   { "UPC2", "345" },
   { "UPC3", "567" }
};

用法

var upc = dict
   .Where(x => x.Key.StartsWith("UPC"))
   .Select(x => x.Value);

var newDict = dict
   .Where(x => !x.Key.StartsWith("UPC"))
   .ToDictionary(x => x.Key, x => x.Value);

newDict.Add("UPC", string.Join(",", upc));


foreach (var item in newDict)
    Console.WriteLine(item.Key   " : "  item.Value);

輸出

asd : dfgdfg
ghj : ghj
UPC : 123,345,567

uj5u.com熱心網友回復：

首先提取所有 UPC 元素并根據需要創建其值，然后將其附加到沒有 UPC 元素的新陣列中

            var dict = new Dictionary<string, string>
        {
            {"Modified by", "Stuart gill" },
            {"Modified on", "11/2/2021" },
            {"UPC0", "000000000333" },
            {"UPC2", "789789789" },
        };

       var keyValueWithUpc = dict.Where(kv => kv.Key.StartsWith("UPC")).ToArray();
       var upcValue = string.Join(",", keyValueWithUpc.Select(kv => kv.Value));
       var result = dict.Except(keyValueWithUpc)
                         .Append(new KeyValuePair<string, string>("UPC", upcValue))
                         .ToDictionary(x => x.Key, x => x.Value);

Append 方法：它需要源（要追加的集合）一個陣列而不是一個，只是為了與現有的一個區分，但由于它作為引數，您也可以傳遞單個專案

public static class ExtensionMethods
{
    public static IEnumerable<T> Append<T>(this IEnumerable<T> source, params T[] itemsToAppend)
    {
        return source.Concat(itemsToAppend);
    }
}

uj5u.com熱心網友回復：

TheGeneral 用他的代碼示例為我指明了正確的方向。這是我的解決方案。下面傳入日志資訊。

StringBuilder sb = new StringBuilder();
        Dictionary<string, string> information = new Dictionary<string, string>();
        List<string> changes = log.Changes.ToString().Split('?').ToList();
        changes.RemoveAt(changes.Count - 1);
        
        int start = 0;
        
        foreach (string units in changes)
        {
            string[] unit = units.Split('|');
            string[] parts = unit[0].Split('-');
            string[] values = unit[1].Split('^');

            string field = parts[1];
            string orig = values[0];
            
            if (unit[0] == "VendorPartUpc-UPC")
            {
                information.Add(field start, values[1]);
                start = start   1;
            }
            else if (values.Count() > 1 && (orig != string.Empty || values[1] != string.Empty) && !information.ContainsKey(field))
                information.Add(field, values[1]);
        }

        //Remove any duplicates
        List<string> vals = new List<string>();
        Dictionary<string, string> newDict = new Dictionary<string, string>();
        foreach (KeyValuePair<string, string> item in information)
        {
            if (!vals.Contains(item.Value))
            {
                newDict.Add(item.Key, item.Value);
                vals.Add(item.Value);
            }
        }
        
        //Need to take the UPCs from multiple key/value pairs, extract just the UPC value and put into a single value with UPC as the key.
        var newDictJustUPCs = newDict.Where(kvp => kvp.Key.Contains("UPC"));
        var upc = newDictJustUPCs
            .Where(x => x.Key.StartsWith("UPC"))
            .Select(x => x.Value);

        newDict.Add("UPC", string.Join(",", upc));
         
        information = newDict;

        return information;

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