The row already belongs to another table

When NCRE was optimized, an error like this was reported: The line change already belongs to another table. The starting reason for the error is that I want to assign a row of a datatable table to another datatable.

The solution is: first add the corresponding column name to the datatable that receives the data

#region  为table1和table2加入对应的列名
            for (int j = 0; j < dt.Columns.Count; j++)
            {
                table1.Columns.Add(dt.Columns[j].ColumnName);//有重载的方法，可以加入列数据的类型
            }
            for (int j = 0; j < dt.Columns.Count; j++)
            {
                table2.Columns.Add(dt.Columns[j].ColumnName);//有重载的方法，可以加入列数据的类型
            }
            #endregion

Then declare a row, assign a value to the row, and then add the row to the table.

for (int i = 1; i < dt.Rows.Count; i++)
            {
                studentInfo.studentID = Convert.ToString(dt.Rows[i][0]);
                DataTable table = addStudent.SelectStudent(studentInfo);
                if (table.Rows.Count > 0)
                {                   
                    //声明一个行
                    DataRow drq = table1.NewRow();
                    drq.ItemArray = dt.Rows[i].ItemArray;
                    table1.Rows.Add(drq);                   
                }
                else
                {
                    DataRow drq = table2.NewRow();
                    drq.ItemArray = dt.Rows[i].ItemArray;
                    table2.Rows.Add(drq);
                }               
            }   

In this way, a row in one datatable can be successfully assigned to another datatable.