无法添加已存在的实体

Question

我在提交更改时收到错误“无法添加已存在的实体”但我设置了一个新ID，该ID在每条记录（主键）上都是唯一的

protected void lbtnAddEdit_Click(object sender, EventArgs e)
    {
        ExcelImportDataContext dc = new ExcelImportDataContext();
        DataTable dtCustomers = (DataTable)ViewState["dtCustomers"];

        Customer obj = new Customer();

        int count = 0;


            if (dtCustomers != null && dtCustomers.Rows.Count > 0)
            {
                dtCustomers.Columns.Add("-Select-");

                foreach (DataRow row in dtCustomers.Rows)
                {
                    row["-Select-"] = string.Empty;

                    obj.name= row[id1.SelectedValue].ToString();
                    obj.surename= row[id2.SelectedValue].ToString();
                    obj.phoneNumber= row[id3.SelectedValue].ToString();


                dc.Customers.InsertOnSubmit(obj);

                    dc.SubmitChanges();


                }
            }

Answer 1

Oups我的不好，我从foreach循环中Customer obj = new Customer();

解决！

欢迎您建议我改变一些事情。

int count = 0;

        if (dtCustomers != null && dtCustomers.Rows.Count > 0)
        {
            dtCustomers.Columns.Add("-Select-");
            foreach (DataRow row in dtCustomers.Rows)
            {
                Customer obj = new Customer();
                row["-Select-"] = string.Empty;