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  • GroupBy

    GroupBy
    private void LoadData()
            {
                DataTable dataTable = new DataTable();
                dataTable.Columns.Add("key", typeof(string));
                dataTable.Columns.Add("value", typeof(decimal));
                dataTable.Rows.Add(new object[] { "123", 10 });
                dataTable.Rows.Add(new object[] { "123", 50 });
                dataTable.Rows.Add(new object[] { "234", 30 });
                dataTable.Rows.Add(new object[] { "235", 30 });
                dataTable.Rows.Add(new object[] { "236", 30 });
                dataTable.Rows.Add(new object[] { "236", 30 });
                dataTable.Rows.Add(new object[] { "237", 30 });
                dataTable.Rows.Add(new object[] { "237", 30 });
                dataTable.Rows.Add(new object[] { "237", 30 });
                dataTable.Rows.Add(new object[] { "240", 30 });
                dataTable.Rows.Add(new object[] { "240", 30 });
                dataTable.Rows.Add(new object[] { "240", 30 });
    
                var list = dataTable.Rows.Cast<DataRow>().GroupBy(d => d.Field<string>("key")).Select(g => new { key = g.Key, value = g.Sum(a=>a.Field<decimal>("value")) }).ToList();
                gridControl1.DataSource = list;
    
                nMax = list.Count();
                pageCount = nMax / pageSize;
    
                bindingSource1.DataSource = list;
                bindingNavigator1.BindingSource = bindingSource1;
                //gridControl1.DataSource = bindingSource1;
            }
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  • 原文地址:https://www.cnblogs.com/mapstar/p/13892706.html
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