无法将类型"int"隐式转换为"string"

#region 得到一个对象实体
public static shubuy GetModel(int Buy_id)
{
SqlParameter[] parameters =
{
new SqlParameter ("@Buy_id",SqlDbType.Int,4)
};
parameters[0].Value = Buy_id;
Customer model = new Customer();

DataSet ds = DbHelperSql.RunProcedure("UP_Customer_GetModel", parameters, "ds");
model.Buy_id = Buy_id;// 就是这 错误 说无法将类型"int"隐式转换为"string"
if (ds.Tables[0].Rows.Count > 0)
{
model.SupplyType = ds.Tables[0].Rows[0]["SupplyType"].ToString();
model.Supplykind = ds.Tables[0].Rows[0]["Supplykind"].ToString();
model.SupplyPro = ds.Tables[0].Rows[0]["SupplyPro"].ToString();
model.Intrduce = ds.Tables[0].Rows[0]["Intrduce"].ToString();
model.OncePro = ds.Tables[0].Rows[0]["OncePro"].ToString();
model.HopeProvice = ds.Tables[0].Rows[0]["HopeProvice"].ToString();
model.HopeArea = ds.Tables[0].Rows[0]["HopeArea"].ToString();
model.Degree = ds.Tables[0].Rows[0]["Degree"].ToString();
model.Fax = ds.Tables[1].Rows[0]["Fax"].ToString();
model.People = ds.Tables[0].Rows[0]["People"].ToString();
model.Tel = ds.Tables[0].Rows[0]["Tel"].ToString();
model.MailMan = ds.Tables[0].Rows[0]["MailMan"].ToString();
model.E_mail = ds.Tables[0].Rows[0]["E_mail"].ToString();
model.QQMSN = ds.Tables[0].Rows[0]["QQMSN"].ToString();
model.ComAdd = ds.Tables[0].Rows[0]["ComAdd"].ToString();
model.ComName = ds.Tables[0].Rows[0]["ComName"].ToString();
model.Remark = ds.Tables[0].Rows[0]["Remark"].ToString();
}
else
{
return null;
}
}
#endregion

 

那写成
model.Buy_id = Buy_id.ToString();
就行了