Excel导入DataTable（二）

这种方法导入DataTable是利用 Excel.Range的Value2属性。和导出Excel（一）是一个相反的过程。一般情况下不建议使用这种方法。

/// <summary>
/// Excel导入DataTable
/// </summary>
/// <param name="strFileName">文件名称</param>
/// <param name="isHead">是否包含表头</param>
/// <param name="iSheet">Sheet</param>
/// <param name="strErrorMessage">错误信息</param>
/// <param name="iRowsIndex">导入的Excel的开始行</param>
/// <returns></returns>
public static DataTable GetDataFromExcel(string strFileName, bool isHead, int iSheet,
ref string strErrorMessage,int iRowsIndex)
{
if (!strFileName.ToUpper().EndsWith(".XLS"))
{
strErrorMessage = "文件类型与系统设定不一致，请核对！";
return null;
}

Excel.Application appExcel = new Excel.Application();
Excel.Workbook workbookData;
Excel.Worksheet worksheetData;

workbookData = appExcel.Workbooks.Open(strFileName, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value,
Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value);

worksheetData = (Excel.Worksheet)workbookData.Sheets[iSheet];

Excel.Range xlRang = null;
int iRowCount = worksheetData.UsedRange.Cells.Rows.Count;
int iParstedRow = 0, iCurrSize = 0;
int iEachSize = 1000; // each time you
int iColumnAccount = worksheetData.UsedRange.Cells.Columns.Count;
int iHead = iRowsIndex;

if (isHead)
iHead = iRowsIndex+1;

DataTable dt = new DataTable();
for (int i = 1; i <= iColumnAccount; i++)
{
if (isHead)
dt.Columns.Add(worksheetData.get_Range(worksheetData.Cells[iRowsIndex, i], worksheetData.Cells[iRowsIndex, i]).Text.ToString());
else
dt.Columns.Add("Columns" + i.ToString());
}

object[,] objVal = new object[iEachSize, iColumnAccount];
try
{
iCurrSize = iEachSize;
while (iParstedRow < iRowCount)
{
if ((iRowCount - iParstedRow) < iEachSize)
iCurrSize = iRowCount - iParstedRow;

xlRang = worksheetData.get_Range("A" + ((int)(iParstedRow + iHead)).ToString(), ((char)('A' + iColumnAccount - 1)).ToString()
+ (((int)(iParstedRow + iCurrSize + 1)).ToString()));

objVal = (object[,])xlRang.Value2;

int iLength = objVal.Length / iColumnAccount;

for (int i = 1; i < iLength; i++)
{
DataRow dr = dt.NewRow();
for (int j = 1; j <= iColumnAccount; j++)
{
if (objVal[i, j] != null)
{
dr[j - 1] = objVal[i, j].ToString();
}

}

dt.Rows.Add(dr);
}

iParstedRow = iParstedRow + iCurrSize;

}
System.Runtime.InteropServices.Marshal.ReleaseComObject(xlRang);
xlRang = null;

}
catch (Exception ex)
{
appExcel.Quit();
strErrorMessage = ex.Message;
return null;
}

appExcel.Quit();

return dt;

}