在c#中从excel数据创建HashMap

本文关键字：创建 HashMap 数据 excel 中从 | 更新日期: 2023-09-27 18:13:38

我是c#的新手，我有一个有2列的excel工作表，我想在该工作表中创建一个hashmap的日期。假设excel表格看起来像

 A         Value1
 A         Value2
 A         Value3
 B         value4
 B         value5

，其中A和B在第一列，值在第二列

我想创建一个像

这样的hashmap
HashMap<String, List<String>>();

其中String将是键，List将是该键的值

有什么想法吗?

谢谢

在c#中从excel数据创建HashMap

我使用这篇文章作为参考。因此，您要查找的内容可能像这样:

查看我如何使用字典而不是HashMap 

//import the references needed. Checkout the article
public static void getExcelFile()
{
    //Create COM Objects. Create a COM object for everything that is referenced
    Excel.Application xlApp = new Excel.Application();
    Excel.Workbook xlWorkbook = xlApp.Workbooks.Open(@"C:'Users'wearybands'test.xlsx");
    Excel._Worksheet xlWorksheet = xlWorkbook.Sheets[1];
    Excel.Range xlRange = xlWorksheet.UsedRange;
    int rowCount = xlRange.Rows.Count;
    //IMPORTANT SECTION
    var dictionary = new Dictionary<string, List<string>>();
    //iterate over the rows and columns as it appears in the file
    //excel is not zero based!!
    for (int i = 1; i <= rowCount; i++)
    {
        //it would be nice if we add some null checking to these variables
        //so, check the article
        var col1 = xlRange.Cells[i, 1].Value2.ToString();
        var col2 = xlRange.Cells[i, 2].Value2.ToString();
        if (dictionary.ContainsKey(col1))
        {
            var existingList = dictionary[col1];
            existingList.Add(col2);
        } 
        else{
            var newList = new List<string>();
            newList.Add(col2);
            dictionary.Add(col1, newList);
        }
    }
    //Do whatever you'd like with the dictionary
    //It now contains this data: A -> [Value1, Value2, Value3], B -> [Value4, Value5]
    //END OF IMPORTANT SECTION
    //cleanup
    GC.Collect();
    GC.WaitForPendingFinalizers();
    //rule of thumb for releasing com objects:
    //never use two dots, all COM objects must be referenced and released individually
    //ex: [somthing].[something].[something] is bad
    //release com objects to fully kill excel process from running in the background
    Marshal.ReleaseComObject(xlRange);
    Marshal.ReleaseComObject(xlWorksheet);
    //close and release
    xlWorkbook.Close();
    Marshal.ReleaseComObject(xlWorkbook);
    //quit and release
    xlApp.Quit();

    Marshal.ReleaseComObject(xlApp);
}

注意:如果您正在处理日期，并且对这些日期进行计算对您很重要，我会使用DateTime而不是string

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