多个子字符串在MVC Razor视图中不起作用

 @foreach (var i in (List<MyDME.Data.Model.ERNFileRequestDTO>)ViewBag.lst)
                    {
                        for (int j = 0; j < i.Parse835Details.storedChkNo.Count; j++)
                        {

                            <tr>
                                <td>
                                    @i.Parse835Details.storedPayorName[j]
                                </td>
                                <td>
                                    @i.Parse835Details.storedChkNo[j]
                                </td>
                                <td>
                                    @i.Parse835Details.storedTotalBilled[j]

                                </td>
                                <td>
                                    @i.Parse835Details.storedTotalPaid[j]

                                </td>
                                <td>
                              //below line doing substring which is not working
   @(i.Parse835Details.storedChkDate[j].Substring(4, 5) + " " + i.Parse835Details.storedChkDate[j].Substring(6, 7) + " " + i.Parse835Details.storedChkDate[j].Substring(0, 3))
                                   
                                </td>
                                <td>
                                    <a href='/PatientManagement/DownloadUploadedDocument?fileName=@Html.Raw(i.path)'>Download</a>

                                </td>
                            </tr>

下面的错误是

System.ArgumentOutOfRangeException: 'Index and length must refer to a location within the string. Parameter name: length'

20210225 类似于日期格式是以字符串形式出现的,从这个值开始执行子字符串,但不能对多个子字符串执行子字符串。

@i.Parse835Details.storedChkDate[j].Substring(0, 5)

@i.Parse835Details.storedChkDate[j].Substring(4, 5)