c# - 使用linq计算gridview中的特定特征

Question

我想用linq统计gridview中“d”的个数

我的数据集是这样的:

 public DataSet TitForTat()
    {
        DataSet ds = new DataSet();
        DataTable dt = new DataTable("myt");
        dt.Columns.Add(new DataColumn("iteration", typeof(int)));
        dt.Columns.Add(new DataColumn("prison1", typeof(string)));
        dt.Columns.Add(new DataColumn("prison2", typeof (string)));
        prison[] prisons = new prison[2];
        prisons[0] = new prison();
        prisons[1] = new prison();
        //---------------------------
        DataRow dr = dt.NewRow();
        prisons[0]._state = "c";
        prisons[1]._state = valueOfState[rd.Next(0, 1)];
        dr["iteration"] = 0;
        dr["prison1"] = "c";
        dr["prison2"] = prisons[1]._state;
        dt.Rows.Add(dr);
        //----------------------
        for (int i = 1; i <= _iteration; i++)
        {
            prisons[0]._state = prisons[1]._state;
            prisons[1]._state = valueOfState[rd.Next(0, 2)];
            DataRow dr1 = dt.NewRow();
            dr1["iteration"] =i;

            dr1["prison1"] = prisons[0]._state;
            dr1["prison2"] = prisons[1]._state;
            dt.Rows.Add(dr1);
        }

        ds.Tables.Add(dt);
        return ds;
    }

在表格中我有一个 GridView “gvData”:

gvData.DataSource = obj.TitForTat().Tables[0];

我的 gridview 有一列“prison1”，有时是“d”，有时是“c”。我需要使用 linq 计算这些迭代；

Answer 1

您可以使用GroupBy:

var prisonGroups = ((DataTable)gvData.DataSource).AsEnumerable()
    .GroupBy(row => row.Field<string>("prison1"));
int countC = prisonGroups
   .Where(g => g.Key == "c")
   .Sum(g => g.Count());
int countD = prisonGroups
   .Where(g => g.Key == "d")
   .Sum(g => g.Count());

这是另一种方法:

DataTable source = (DataTable)gvData.DataSource;
int cPrisoners = source.AsEnumerable()
    .Count(row => row.Field<string>("prison1") == "c");
int dPrisoners = source.AsEnumerable()
    .Count(row => row.Field<string>("prison1") == "d");