我有一个需要解析为 excel 文件的 .xls ( .csv ) 文件。我正在为 NPOI 使用 c# 库的最新稳定版本。问题是我得到了正确的 CSV 而不是标准化的行大小。
What the data in excel file looks like
输出 csv 文件为:
"FirstName","MiddleName","LastName","PhNum"
"John","L","Doe","555-555-5555"
"Little","Ding","Bat"
"Roger","D","Rabbit","123-456-7890"
我希望它发生的是在第二个数据行的末尾(在“Bat”之后)添加一个额外的分隔符，如下所示:
"FirstName","MiddleName","LastName","PhNum"
"John","L","Doe","555-555-5555"
"Little","Ding","Bat",
"Roger","D","Rabbit","123-456-7890"
这是我的代码:
public override bool ParseFile()
{
FileStream iFile = new FileStream(InputFileName, FileMode.Open);
HSSFWorkbook wb = new HSSFWorkbook(iFile);
ExcelExtractor extractor = new ExcelExtractor(wb);
extractor.IncludeBlankCells = true;
bool result = true;
if (AllWorksheets)
{
for (int i = 0; i < wb.NumberOfSheets; i++)
result = result && ParseWorksheet(wb, i);
}
else
{
result = ParseWorksheet(wb, 0);
}
return result;
}
protected char c = '"';
public static string FormatValue(string s, bool AddQuotes, char quoteChar)
{
if (AddQuotes)
{
return quoteChar + s + quoteChar;
}
return s;
}
private bool ParseWorksheet(HSSFWorkbook wb, int SheetIndex)
{
bool result = true;
HSSFSheet sheet = (HSSFSheet)wb.GetSheetAt(SheetIndex);
if (sheet.FirstRowNum == sheet.LastRowNum && sheet.LastRowNum == 0) return result;
System.IO.StreamWriter sw = new StreamWriter(OutputFileName, true);
for (int i = sheet.FirstRowNum; i <= sheet.LastRowNum; i++)
{
string OutputRow = String.Empty;
HSSFRow row = (HSSFRow)sheet.GetRow(i);
int Column = 0;
int MaxCol = 0;
int temp = 0;
for (int j = 0; j < row.LastCellNum; j++)
{
temp = row.LastCellNum;
if (temp > MaxCol)
{
MaxCol = temp;
}
}
for (int j = 0; j < MaxCol; j++)
{
if (j == row.Cells[Column].ColumnIndex)
{
switch (row.Cells[Column].CellType)
{
case NPOI.SS.UserModel.CellType.Boolean:
OutputRow += FormatValue(row.Cells[Column].BooleanCellValue.ToString(), AddQuotes, c) + Delimiter.ToString();
break;
case NPOI.SS.UserModel.CellType.Formula:
OutputRow += FormatValue(row.Cells[Column].CachedFormulaResultType.ToString(), AddQuotes, c) + Delimiter.ToString();
break;
case NPOI.SS.UserModel.CellType.Numeric:
OutputRow += FormatValue((NPOI.SS.UserModel.DateUtil.IsCellDateFormatted(row.Cells[Column]) ? row.Cells[Column].DateCellValue.ToShortDateString() : row.Cells[Column].NumericCellValue.ToString()), AddQuotes, c) + Delimiter.ToString();
break;
case NPOI.SS.UserModel.CellType.Blank:
OutputRow += Delimiter.ToString();
break;
case NPOI.SS.UserModel.CellType.String:
OutputRow += FormatValue(row.Cells[Column].StringCellValue.ToString().Replace('\n', ' ').TrimEnd(), AddQuotes, c) + Delimiter.ToString();//replace the new line character to space due to formatting issue.
break;
default:
result = false;
break;
}
Column++;
}
else
{
OutputRow += Delimiter.ToString();
}
}
OutputRow = OutputRow.Remove(OutputRow.Length - 1);
sw.WriteLine(OutputRow);
}
sw.Flush();
sw.Close();
return result;
}`
任何建议将不胜感激。
最佳答案
这里有几个问题导致了这个问题。
首先，您正在重新计算 MaxCol对于每一行。如果你想要一个非参差不齐的右边缘，那么你需要找到 MaxCol首先遍历所有行，然后生成输出。
其次，您使用的是 row.Cells[]尝试获取该行的特定单元格。 Cells[]忽略空值。所以如果你碰巧在行的某处有一个空白单元格，那么所有剩余的值都会向左移动，数组的长度会小于MaxCol。 .如果您尝试访问 row.Cells[MaxCol - 1]，这将导致异常。在至少有一个空白值的行上。
此问题的解决方案是使用 row.GetCell(index)代替方法。此方法返回列 index 处的单元格(从 0 开始)，或 null如果该单元格为空。它使用起来更加直接，并且允许您消除代码中检查 ColumnIndex 的特殊逻辑。当前单元格的循环索引 j确保您得到的单元格确实在您期望的列中。
作为一个额外的建议，我建议在内部循环中只检索一次当前单元格并将其分配给一个变量，而不是多次重新检索它。这将使您的代码更高效且更易于阅读。
这是 ParseWorksheet 的修订代码具有上述所有更改的方法:
private bool ParseWorksheet(HSSFWorkbook wb, int SheetIndex)
{
bool result = true;
HSSFSheet sheet = (HSSFSheet)wb.GetSheetAt(SheetIndex);
if (sheet.FirstRowNum == sheet.LastRowNum && sheet.LastRowNum == 0) return result;
StreamWriter sw = new StreamWriter(OutputFileName, true);
int MaxCol = 0;
for (int i = sheet.FirstRowNum; i <= sheet.LastRowNum; i++)
{
HSSFRow row = (HSSFRow)sheet.GetRow(i);
MaxCol = Math.Max(MaxCol, row.LastCellNum);
}
for (int i = sheet.FirstRowNum; i <= sheet.LastRowNum; i++)
{
string OutputRow = String.Empty;
HSSFRow row = (HSSFRow)sheet.GetRow(i);
for (int j = 0; j < MaxCol; j++)
{
HSSFCell cell = (HSSFCell)row.GetCell(j);
if (cell != null)
{
switch (cell.CellType)
{
case NPOI.SS.UserModel.CellType.Boolean:
OutputRow += FormatValue(cell.BooleanCellValue.ToString(), AddQuotes, c) + Delimiter;
break;
case NPOI.SS.UserModel.CellType.Formula:
OutputRow += FormatValue(cell.CachedFormulaResultType.ToString(), AddQuotes, c) + Delimiter;
break;
case NPOI.SS.UserModel.CellType.Numeric:
OutputRow += FormatValue((NPOI.SS.UserModel.DateUtil.IsCellDateFormatted(cell) ? cell.DateCellValue.ToShortDateString() : cell.NumericCellValue.ToString()), AddQuotes, c) + Delimiter;
break;
case NPOI.SS.UserModel.CellType.Blank:
OutputRow += Delimiter;
break;
case NPOI.SS.UserModel.CellType.String:
OutputRow += FormatValue(cell.StringCellValue.ToString().Replace('\n', ' ').TrimEnd(), AddQuotes, c) + Delimiter; //replace the new line character to space due to formatting issue.
break;
default:
result = false;
break;
}
}
else
{
OutputRow += Delimiter;
}
}
OutputRow = OutputRow.Remove(OutputRow.Length - 1);
sw.WriteLine(OutputRow);
}
sw.Flush();
sw.Close();
return result;
}
关于c# - 如何使用 NPOI 获得非参差不齐的右列，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/39537600/