Question

过去的问题主题并链接到完整代码HERE

我使用参数类创建我的字典，因此它可以包含两个string值。现在我正在尝试在此类中的两个字符串中写TryGetValue到out：

public class DictionaryInitializer
{
    public class DictionarySetup
    {
        public string theDescription { get; set; }
        public string theClass { get; set; }
    }

如您所见，theDescription嵌套theClass和DictionarySetup。然后我会在这里使用该类创建词典：

    public class DictionaryInit
    {
        //IS_Revenues data
        public Dictionary<int, DictionarySetup> accountRevenue = new Dictionary<int, DictionarySetup>()
            {
                { 400000, new DictionarySetup {theDescription="Call", theClass="Revenues"}}
            };
        public Dictionary<int, DictionarySetup> accountExpenses = new Dictionary<int, DictionarySetup>()
            {
                {790100, new DictionarySetup { theDescription="Currency Hedge", theClass="Other income/expense"}}
            };
    }

然后，我计划在字典上使用TryGetValue的扩展方法：

    public void DictionaryUseKey(int MapCode, int MapKey, int rowindex, Dictionary<int, DictionarySetup> AccountLexicon)
    {
        AccountLexicon[1] = new DictionarySetup();
        DictionarySetup Classes;
        DictionarySetup Descriptions;
        //Saw the above code in another thread, not sure if it's what I should be doing but it seems pretty close to what I want, however, I don't know how to specify the DictionarySetup.theDescription for example;
        AccountLexicon.TryGetValue(MapKey, out Classes);
        {
            //I want to be able to write theDescription and theClass into string variables for use below if the `TryGetValue` returns true, but it seems to me that it can only out one value? How does this work?
            DGVMain.Rows[rowindex].Cells[3].Value =  ?? how do I write something like...  theValues.theDescription;
            DGVMain.Rows[rowindex].Cells[11].Value = ?? how do I write something like...  theValues.theClass;
        }
    }

最后，我在我的活动中调用扩展方法，如下所示：

    private void btnMapper_Click(object sender, EventArgs e)
    {
        for (int rowindex = 0; rowindex < DGVMain.RowCount; rowindex++)
        {
            int accountKey = Convert.ToInt32(DGVMain.Rows[rowindex].Cells[2].Value);
            int projCode = Math.Abs(Convert.ToInt32(DGVMain.Rows[rowindex].Cells[7].Value));
            int deptCode = Math.Abs(Convert.ToInt32(DGVMain.Rows[rowindex].Cells[9].Value));
            int AbsoluteKey = Math.Abs(accountKey);
            while (AbsoluteKey >= 10) { AbsoluteKey /= 10; }
            while (deptCode >= 10) { deptCode /= 10; }
            theDictionary = new DictionaryInit();
            DictionaryUseKey(deptCode, accountKey, theDictionary.accountRevenue);
        }
    }

Answer 1

实际上TryGetValue方法将返回一个布尔值，表示存在指定的键，如果找到该键，则相应的值将存储在out参数中。在您的情况下，out参数为Classes，并在您的代码中定义如下：DictionarySetup Classes。这意味着如果密钥出现在字典中，则相应的DictionarySetup对象将存储在Classes中，以便您可以从theDescription访问theClass和Classes };请考虑以下代码：

 if(AccountLexicon.TryGetValue(MapKey, out Classes))
 {
    DGVMain.Rows[rowindex].Cells[3].Value =  Classes.theDescription;
    DGVMain.Rows[rowindex].Cells[11].Value = Classes.theClass;
 }

在Dictionary TryGetValue中，如果它是类的一部分，如何编写out参数（并获取它的值）？

1 个答案: