无法在LINQ方法下施放类型的对象

Question

我在下面的代码行号（var ColumnNames =）中获得以下错误。

`System.InvalidCastException: 'Unable to cast object of type 'System.Object' to type 'System.Collections.Generic.Dictionary`2[System.String,System.Object]'.'`

Javscript控制台中的代码

 public JsonResult SaveData(List<object> customers)
        {
            DataTable dt = new DataTable();
            
            var columnNames = ((Dictionary<string, object>)customers[0]).Select(x => x.Key).ToList();
            for (int i = 0; i < columnNames.Count(); i++)
            {
                dt.Columns.Add(columnNames[i]);
            }
            foreach (Dictionary<string, object> customer in customers)
            {
                DataRow dr = dt.NewRow();
                for (int i = 0; i < columnNames.Count(); i++)
                {
                    dr[columnNames[i]] = customer[columnNames[i]];
                }
                dt.Rows.Add(dr);
            }

    

            return Json('1');

        }

显示传递数据

0 : {Id: "1", Name: "abc", Country: "uk", __rowNum__: 1}
1: {Id: "2", Name: "kala", Country: "us", __rowNum__: 2}
2: {Id: "3", Name: "Has", Country: "IN", __rowNum__: 3}

Answer 1

您需要进行反思。

var columnNames = customers[0]
    .GetType()
    .GetProperties()
    .Select(x => x.Name)
    .ToList();

foreach (var customer in customers)
{
    DataRow dr = dt.NewRow();
    for (int i = 0; i < columnNames.Count(); i++)
    {
        PropertyInfo prop = customer.GetType().GetProperty(columnNames[i]);
        dr[columnNames[i]] = prop.GetValue(customer);
    }

    dt.Rows.Add(dr);
}

sample .net小提琴