为什么我得到＆＃34;索引无效＆＃34;在尝试将第三张表添加到我的电子表格时？

Question

我已经有了添加第三张表的代码：

// contextual code
private Excel.Application _xlApp;
private Excel.Workbook _xlBook;
private Excel.Sheets _xlSheets;
private Excel.Worksheet _xlSheet;
private Excel.Worksheet _xlSheetDelPerf;
private Excel.Worksheet _xlSheetListObjectTest;

// the line that kablooeys (sp?):
_xlSheetListObjectTest = (Excel.Worksheet)_xlSheets.Item[3]; // <= this is line 307, made infamous in the err msg screenshotted below

添加表1：

_xlSheet = (Excel.Worksheet)_xlSheets.Item[1];

...和2：

_xlSheetDelPerf = (Excel.Worksheet)_xlSheets.Item[2];

...工作正常，但当我点击kablooifies（项目[3]）时，我得到：

为什么呢？我拿了一张传单改了这个：

_xlApp.SheetsInNewWorkbook = 1; // prevent the empty "sheet 2" etc.

......对此：

_xlApp.SheetsInNewWorkbook = 3; // prevent the empty "sheet 2" etc.

...以防万一设置＆＃34; SheetsInNewWorkbook＆＃34;为1阻止我添加更多的床单，但不，它没有任何区别。

那么为什么＆＃34; 3＆＃34; ＆＃34; 2＆＃34;很好吗？

更新

对于要求更多背景的Yacoub Massad：

_xlBook = _xlApp.Workbooks.Add(Type.Missing);
_xlBook.Worksheets.Add(Type.Missing, Type.Missing, Type.Missing, Type.Missing);

_xlApp.ActiveWindow.DisplayGridlines = false;
_xlApp.SheetsInNewWorkbook = 3; // prevent the empty "sheet 2" etc.
_xlSheets = _xlBook.Worksheets;

_xlSheet = (Excel.Worksheet)_xlSheets.Item[1];

如果附加＆＃34; _xlBook.Worksheets.Add（）＆＃34;第3页需要，为什么不使用第2页？

更新2

这给了我＆＃34; InvalidIndex＆＃34;在＆＃34;项目[0]＆＃34;如下所示：

_xlApp.ErrorCheckingOptions.BackgroundChecking = false;
_xlApp.SheetsInNewWorkbook = 3;

_xlBook = _xlApp.Workbooks.Add(Type.Missing);
_xlBook.Worksheets.Add(Type.Missing, Type.Missing, Type.Missing, Type.Missing);
_xlBook.Worksheets.Add(Type.Missing, Type.Missing, Type.Missing, Type.Missing);
_xlBook.Worksheets.Add(Type.Missing, Type.Missing, Type.Missing, Type.Missing);

_xlApp.ActiveWindow.DisplayGridlines = false;

_xlSheets = _xlBook.Worksheets;

_xlSheet = (Excel.Worksheet)_xlSheets.Item[0]; // changed to 0 from 1
_xlSheetDelPerf = (Excel.Worksheet)_xlSheets.Item[1]; // changed to 1 from 2
_xlSheetListObjectTest = (Excel.Worksheet)_xlSheets.Item[2]; // changed to 2 from 3

更新3

我将更新2中的代码更改为原始索引1,2和3（替换建议的0,1和2），我不再使用＃34; InvalidIndex＆＃34;那里;但是，我现在进一步向下，在这个调用Sort（）：

fruitList.Range.Sort(
    fruitList.ListColumns[1].Range, Excel.XlSortOrder.xlAscending,
    fruitList.ListColumns[2].Range, Type.Missing, 
        Excel.XlSortOrder.xlAscending,
        Type.Missing, Excel.XlSortOrder.xlAscending,
        Excel.XlYesNoGuess.xlYes, Type.Missing, Type.Missing,
        Excel.XlSortOrientation.xlSortColumns);

在上下文中：

private void WriteListObjectTestSheet()
{
    //_xlBook.Worksheets.Add(Type.Missing, Type.Missing, Type.Missing, Type.Missing); // see if this helps
    //_xlSheetListObjectTest = (Excel.Worksheet)_xlSheets.Item[2]; // changed to 2 from 3
    _xlSheetListObjectTest.Name = ProduceUsageListObjectSortSheetName;

    _xlSheetListObjectTest.Cells[5, 1] = "Apple";
    _xlSheetListObjectTest.Cells[6, 1] = "Strawberry";
    _xlSheetListObjectTest.Cells[7, 1] = "Cashew";
    _xlSheetListObjectTest.Cells[8, 1] = "Kumquat";
    _xlSheetListObjectTest.Cells[9, 1] = "Pomegranate";
    _xlSheetListObjectTest.Cells[10, 1] = "Banana";
    _xlSheetListObjectTest.Cells[11, 1] = "Pineapple";
    _xlSheetListObjectTest.Cells[12, 1] = "Kiwi";
    _xlSheetListObjectTest.Cells[13, 1] = "Huckleberry";
    _xlSheetListObjectTest.Cells[14, 1] = "Gooseberry";

    Excel.ListObject fruitList =
        _xlSheetListObjectTest.
            ListObjects.Add(Excel.XlListObjectSourceType.xlSrcRange,
                _xlSheetListObjectTest.Range[
                    _xlSheetListObjectTest.Cells[4, 1],
                    _xlSheetListObjectTest.Cells[4, 1]], //13]], 
                Type.Missing, Excel.XlYesNoGuess.xlNo);

    fruitList.Range.Sort(
        fruitList.ListColumns[1].Range, Excel.XlSortOrder.xlAscending,
        fruitList.ListColumns[2].Range, Type.Missing, 
            Excel.XlSortOrder.xlAscending,
            Type.Missing, Excel.XlSortOrder.xlAscending,
            Excel.XlYesNoGuess.xlYes, Type.Missing, Type.Missing,
            Excel.XlSortOrientation.xlSortColumns);
}

我广告[a，o]来自here的代码，并承认我并非真正理解它;我认为问题出在ListColumns 1和/或ListColumns 2中，但不知道为什么......

Answer 1

移动此行：

_xlApp.SheetsInNewWorkbook = 3;

在此之前：

_xlBook = _xlApp.Workbooks.Add(Type.Missing);

顾名思义，SheetsInNewWorkbook设置了尚未创建的工作簿的工作表数量，而不是已经创建的工作簿数量。

Answer 2

实际上，当您使用以下代码(Excel.Worksheet)_xlSheets.Item[3]时，您正尝试访问第4张而非第3张，因为它的基于零的索引。