我有很多包含数据的excel文件,其中包含空行和空列。如下图所示
我正在尝试使用互操作从excel中删除空行和空列。我创建了一个简单的winform应用程序,并使用了以下代码,它工作得很好。
Dim lstFiles As New List(Of String)
lstFiles.AddRange(IO.Directory.GetFiles(m_strFolderPath, "*.xls", IO.SearchOption.AllDirectories))
Dim m_XlApp = New Excel.Application
Dim m_xlWrkbs As Excel.Workbooks = m_XlApp.Workbooks
Dim m_xlWrkb As Excel.Workbook
For Each strFile As String In lstFiles
m_xlWrkb = m_xlWrkbs.Open(strFile)
Dim m_XlWrkSheet As Excel.Worksheet = m_xlWrkb.Worksheets(1)
Dim intRow As Integer = 1
While intRow <= m_XlWrkSheet.UsedRange.Rows.Count
If m_XlApp.WorksheetFunction.CountA(m_XlWrkSheet.Cells(intRow, 1).EntireRow) = 0 Then
m_XlWrkSheet.Cells(intRow, 1).EntireRow.Delete(Excel.XlDeleteShiftDirection.xlShiftUp)
Else
intRow += 1
End If
End While
Dim intCol As Integer = 1
While intCol <= m_XlWrkSheet.UsedRange.Columns.Count
If m_XlApp.WorksheetFunction.CountA(m_XlWrkSheet.Cells(1, intCol).EntireColumn) = 0 Then
m_XlWrkSheet.Cells(1, intCol).EntireColumn.Delete(Excel.XlDeleteShiftDirection.xlShiftToLeft)
Else
intCol += 1
End If
End While
Next
m_xlWrkb.Save()
m_xlWrkb.Close(SaveChanges:=True)
Marshal.ReleaseComObject(m_xlWrkb)
Marshal.ReleaseComObject(m_xlWrkbs)
m_XlApp.Quit()
Marshal.ReleaseComObject(m_XlApp)
但是,当清理大的excel文件时,需要花费大量的时间。对优化这段代码有什么建议吗?或者用另一种方法来更快地清理这个excel文件?有没有可以一键删除空行的功能?
如果答案使用C#,我不会有问题
编辑:
我上传了一个示例文件Sample File。但并不是所有的文件都有相同的结构。
发布于 2016-11-22 01:48:12
我发现,如果工作表很大,遍历excel工作表可能需要一些时间。因此,我的解决方案试图避免工作表中的任何循环。为了避免循环遍历工作表,我使用以下命令从usedRange
返回的单元格创建了一个二维对象数组:
Excel.Range targetCells = worksheet.UsedRange;
object[,] allValues = (object[,])targetCells.Cells.Value;
这是我循环通过的数组,以获取空行和空列的索引。我做了两个int列表,一个保留行索引以删除,另一个保留列索引以删除。
List<int> emptyRows = GetEmptyRows(allValues, totalRows, totalCols);
List<int> emptyCols = GetEmptyCols(allValues, totalRows, totalCols);
这些列表将从高到低排序,以简化从下到上删除行和从右到左删除列的过程。然后简单地遍历每个列表并删除适当的行/列。
DeleteRows(emptyRows, worksheet);
DeleteCols(emptyCols, worksheet);
最后,在删除所有空行和空列之后,我将文件另存为一个新的文件名。
希望这能有所帮助。
编辑:
解决了UsedRange问题,如果工作表顶部有空行,这些行现在将被删除。此外,这将删除起始数据左侧的所有空列。这样,即使在数据开始之前有空行或空列,索引也可以正常工作。这是通过获取UsedRange中第一个单元的地址来实现的。这将是一个“$A$1:$D$4”形式的地址。如果要保留顶部的空行和左侧的空列而不删除,这将允许使用偏移量。在这种情况下,我只是简单地删除它们。要获取要从顶部删除的行数,可以通过第一个“$A$4”地址计算,其中“4”是第一个数据出现的行。所以我们需要删除前3行。列地址的形式是“A”,“AB”,甚至“AAD”,这需要一些转换,多亏了How to convert a column number (eg. 127) into an excel column (eg. AA),我能够确定左侧有多少列需要删除。
class Program {
static void Main(string[] args) {
Excel.Application excel = new Excel.Application();
string originalPath = @"H:\ExcelTestFolder\Book1_Test.xls";
Excel.Workbook workbook = excel.Workbooks.Open(originalPath);
Excel.Worksheet worksheet = workbook.Worksheets["Sheet1"];
Excel.Range usedRange = worksheet.UsedRange;
RemoveEmptyTopRowsAndLeftCols(worksheet, usedRange);
DeleteEmptyRowsCols(worksheet);
string newPath = @"H:\ExcelTestFolder\Book1_Test_Removed.xls";
workbook.SaveAs(newPath, Excel.XlSaveAsAccessMode.xlNoChange);
workbook.Close();
excel.Quit();
System.Runtime.InteropServices.Marshal.ReleaseComObject(workbook);
System.Runtime.InteropServices.Marshal.ReleaseComObject(excel);
Console.WriteLine("Finished removing empty rows and columns - Press any key to exit");
Console.ReadKey();
}
private static void DeleteEmptyRowsCols(Excel.Worksheet worksheet) {
Excel.Range targetCells = worksheet.UsedRange;
object[,] allValues = (object[,])targetCells.Cells.Value;
int totalRows = targetCells.Rows.Count;
int totalCols = targetCells.Columns.Count;
List<int> emptyRows = GetEmptyRows(allValues, totalRows, totalCols);
List<int> emptyCols = GetEmptyCols(allValues, totalRows, totalCols);
// now we have a list of the empty rows and columns we need to delete
DeleteRows(emptyRows, worksheet);
DeleteCols(emptyCols, worksheet);
}
private static void DeleteRows(List<int> rowsToDelete, Excel.Worksheet worksheet) {
// the rows are sorted high to low - so index's wont shift
foreach (int rowIndex in rowsToDelete) {
worksheet.Rows[rowIndex].Delete();
}
}
private static void DeleteCols(List<int> colsToDelete, Excel.Worksheet worksheet) {
// the cols are sorted high to low - so index's wont shift
foreach (int colIndex in colsToDelete) {
worksheet.Columns[colIndex].Delete();
}
}
private static List<int> GetEmptyRows(object[,] allValues, int totalRows, int totalCols) {
List<int> emptyRows = new List<int>();
for (int i = 1; i < totalRows; i++) {
if (IsRowEmpty(allValues, i, totalCols)) {
emptyRows.Add(i);
}
}
// sort the list from high to low
return emptyRows.OrderByDescending(x => x).ToList();
}
private static List<int> GetEmptyCols(object[,] allValues, int totalRows, int totalCols) {
List<int> emptyCols = new List<int>();
for (int i = 1; i < totalCols; i++) {
if (IsColumnEmpty(allValues, i, totalRows)) {
emptyCols.Add(i);
}
}
// sort the list from high to low
return emptyCols.OrderByDescending(x => x).ToList();
}
private static bool IsColumnEmpty(object[,] allValues, int colIndex, int totalRows) {
for (int i = 1; i < totalRows; i++) {
if (allValues[i, colIndex] != null) {
return false;
}
}
return true;
}
private static bool IsRowEmpty(object[,] allValues, int rowIndex, int totalCols) {
for (int i = 1; i < totalCols; i++) {
if (allValues[rowIndex, i] != null) {
return false;
}
}
return true;
}
private static void RemoveEmptyTopRowsAndLeftCols(Excel.Worksheet worksheet, Excel.Range usedRange) {
string addressString = usedRange.Address.ToString();
int rowsToDelete = GetNumberOfTopRowsToDelete(addressString);
DeleteTopEmptyRows(worksheet, rowsToDelete);
int colsToDelete = GetNumberOfLeftColsToDelte(addressString);
DeleteLeftEmptyColumns(worksheet, colsToDelete);
}
private static void DeleteTopEmptyRows(Excel.Worksheet worksheet, int startRow) {
for (int i = 0; i < startRow - 1; i++) {
worksheet.Rows[1].Delete();
}
}
private static void DeleteLeftEmptyColumns(Excel.Worksheet worksheet, int colCount) {
for (int i = 0; i < colCount - 1; i++) {
worksheet.Columns[1].Delete();
}
}
private static int GetNumberOfTopRowsToDelete(string address) {
string[] splitArray = address.Split(':');
string firstIndex = splitArray[0];
splitArray = firstIndex.Split('$');
string value = splitArray[2];
int returnValue = -1;
if ((int.TryParse(value, out returnValue)) && (returnValue >= 0))
return returnValue;
return returnValue;
}
private static int GetNumberOfLeftColsToDelte(string address) {
string[] splitArray = address.Split(':');
string firstindex = splitArray[0];
splitArray = firstindex.Split('$');
string value = splitArray[1];
return ParseColHeaderToIndex(value);
}
private static int ParseColHeaderToIndex(string colAdress) {
int[] digits = new int[colAdress.Length];
for (int i = 0; i < colAdress.Length; ++i) {
digits[i] = Convert.ToInt32(colAdress[i]) - 64;
}
int mul = 1; int res = 0;
for (int pos = digits.Length - 1; pos >= 0; --pos) {
res += digits[pos] * mul;
mul *= 26;
}
return res;
}
}
EDIT 2: For testing我创建了一个遍历工作表的方法,并将其与循环遍历对象数组的代码进行比较。它显示了一个显着的差异。
方法循环访问工作表并删除空行和空列。
enum RowOrCol { Row, Column };
private static void ConventionalRemoveEmptyRowsCols(Excel.Worksheet worksheet) {
Excel.Range usedRange = worksheet.UsedRange;
int totalRows = usedRange.Rows.Count;
int totalCols = usedRange.Columns.Count;
RemoveEmpty(usedRange, RowOrCol.Row);
RemoveEmpty(usedRange, RowOrCol.Column);
}
private static void RemoveEmpty(Excel.Range usedRange, RowOrCol rowOrCol) {
int count;
Excel.Range curRange;
if (rowOrCol == RowOrCol.Column)
count = usedRange.Columns.Count;
else
count = usedRange.Rows.Count;
for (int i = count; i > 0; i--) {
bool isEmpty = true;
if (rowOrCol == RowOrCol.Column)
curRange = usedRange.Columns[i];
else
curRange = usedRange.Rows[i];
foreach (Excel.Range cell in curRange.Cells) {
if (cell.Value != null) {
isEmpty = false;
break; // we can exit this loop since the range is not empty
}
else {
// Cell value is null contiue checking
}
} // end loop thru each cell in this range (row or column)
if (isEmpty) {
curRange.Delete();
}
}
}
然后主要用于测试/计时这两种方法。
enum RowOrCol { Row, Column };
static void Main(string[] args)
{
Excel.Application excel = new Excel.Application();
string originalPath = @"H:\ExcelTestFolder\Book1_Test.xls";
Excel.Workbook workbook = excel.Workbooks.Open(originalPath);
Excel.Worksheet worksheet = workbook.Worksheets["Sheet1"];
Excel.Range usedRange = worksheet.UsedRange;
// Start test for looping thru each excel worksheet
Stopwatch sw = new Stopwatch();
Console.WriteLine("Start stopwatch to loop thru WORKSHEET...");
sw.Start();
ConventionalRemoveEmptyRowsCols(worksheet);
sw.Stop();
Console.WriteLine("It took a total of: " + sw.Elapsed.Milliseconds + " Miliseconds to remove empty rows and columns...");
string newPath = @"H:\ExcelTestFolder\Book1_Test_RemovedLoopThruWorksheet.xls";
workbook.SaveAs(newPath, Excel.XlSaveAsAccessMode.xlNoChange);
workbook.Close();
Console.WriteLine("");
// Start test for looping thru object array
workbook = excel.Workbooks.Open(originalPath);
worksheet = workbook.Worksheets["Sheet1"];
usedRange = worksheet.UsedRange;
Console.WriteLine("Start stopwatch to loop thru object array...");
sw = new Stopwatch();
sw.Start();
DeleteEmptyRowsCols(worksheet);
sw.Stop();
// display results from second test
Console.WriteLine("It took a total of: " + sw.Elapsed.Milliseconds + " Miliseconds to remove empty rows and columns...");
string newPath2 = @"H:\ExcelTestFolder\Book1_Test_RemovedLoopThruArray.xls";
workbook.SaveAs(newPath2, Excel.XlSaveAsAccessMode.xlNoChange);
workbook.Close();
excel.Quit();
System.Runtime.InteropServices.Marshal.ReleaseComObject(workbook);
System.Runtime.InteropServices.Marshal.ReleaseComObject(excel);
Console.WriteLine("");
Console.WriteLine("Finished testing methods - Press any key to exit");
Console.ReadKey();
}
根据操作请求编辑3个...我更新并更改了代码以匹配操作码。有了这个,我发现了一些有趣的结果。见下文。
我更改了代码以匹配您正在使用的函数,即ie…EntireRow和CountA。下面的代码我发现它的表现非常糟糕。运行一些测试,我发现下面的代码的执行时间是800+毫秒。然而,一个细微的变化带来了巨大的不同。
在线上:
while (rowIndex <= worksheet.UsedRange.Rows.Count)
这让事情变慢了很多。如果您为UsedRang创建了一个范围变量,并且不保留regrabbibg,那么while循环的每次迭代都会产生巨大的差异。所以…当我将while循环更改为…时
Excel.Range usedRange = worksheet.UsedRange;
int rowIndex = 1;
while (rowIndex <= usedRange.Rows.Count)
and
while (colIndex <= usedRange.Columns.Count)
这与我的对象数组解决方案非常接近。我没有发布结果,因为您可以使用下面的代码并更改while循环来在每次迭代中获取UsedRange,或者使用变量usedRange来测试这一点。
private static void RemoveEmptyRowsCols3(Excel.Worksheet worksheet) {
//Excel.Range usedRange = worksheet.UsedRange; // <- using this variable makes the while loop much faster
int rowIndex = 1;
// delete empty rows
//while (rowIndex <= usedRange.Rows.Count) // <- changing this one line makes a huge difference - not grabbibg the UsedRange with each iteration...
while (rowIndex <= worksheet.UsedRange.Rows.Count) {
if (excel.WorksheetFunction.CountA(worksheet.Cells[rowIndex, 1].EntireRow) == 0) {
worksheet.Cells[rowIndex, 1].EntireRow.Delete(Excel.XlDeleteShiftDirection.xlShiftUp);
}
else {
rowIndex++;
}
}
// delete empty columns
int colIndex = 1;
// while (colIndex <= usedRange.Columns.Count) // <- change here also
while (colIndex <= worksheet.UsedRange.Columns.Count) {
if (excel.WorksheetFunction.CountA(worksheet.Cells[1, colIndex].EntireColumn) == 0) {
worksheet.Cells[1, colIndex].EntireColumn.Delete(Excel.XlDeleteShiftDirection.xlShiftToLeft);
}
else {
colIndex++;
}
}
}
提供的更新
如果excel在上次使用的行和列之后包含额外的空行和列,则可以更改DeleteCols
和DeleteRows
函数以获得更好的性能:
private static void DeleteRows(List<int> rowsToDelete, Microsoft.Office.Interop.Excel.Worksheet worksheet)
{
// the rows are sorted high to low - so index's wont shift
List<int> NonEmptyRows = Enumerable.Range(1, rowsToDelete.Max()).ToList().Except(rowsToDelete).ToList();
if (NonEmptyRows.Max() < rowsToDelete.Max())
{
// there are empty rows after the last non empty row
Microsoft.Office.Interop.Excel.Range cell1 = worksheet.Cells[NonEmptyRows.Max() + 1,1];
Microsoft.Office.Interop.Excel.Range cell2 = worksheet.Cells[rowsToDelete.Max(), 1];
//Delete all empty rows after the last used row
worksheet.Range[cell1, cell2].EntireRow.Delete(Microsoft.Office.Interop.Excel.XlDeleteShiftDirection.xlShiftUp);
} //else last non empty row = worksheet.Rows.Count
foreach (int rowIndex in rowsToDelete.Where(x => x < NonEmptyRows.Max()))
{
worksheet.Rows[rowIndex].Delete();
}
}
private static void DeleteCols(List<int> colsToDelete, Microsoft.Office.Interop.Excel.Worksheet worksheet)
{
// the cols are sorted high to low - so index's wont shift
//Get non Empty Cols
List<int> NonEmptyCols = Enumerable.Range(1, colsToDelete.Max()).ToList().Except(colsToDelete).ToList();
if (NonEmptyCols.Max() < colsToDelete.Max())
{
// there are empty rows after the last non empty row
Microsoft.Office.Interop.Excel.Range cell1 = worksheet.Cells[1,NonEmptyCols.Max() + 1];
Microsoft.Office.Interop.Excel.Range cell2 = worksheet.Cells[1,NonEmptyCols.Max()];
//Delete all empty rows after the last used row
worksheet.Range[cell1, cell2].EntireColumn.Delete(Microsoft.Office.Interop.Excel.XlDeleteShiftDirection.xlShiftToLeft);
} //else last non empty column = worksheet.Columns.Count
foreach (int colIndex in colsToDelete.Where(x => x < NonEmptyCols.Max()))
{
worksheet.Columns[colIndex].Delete();
}
}
在上查看我的答案
发布于 2016-11-13 21:47:30
也许需要考虑的是:
Sub usedRangeDeleteRowsCols()
Dim LastRow, LastCol, i As Long
LastRow = Cells.Find(What:="*", SearchDirection:=xlPrevious, SearchOrder:=xlByRows).Row
LastCol = Cells.Find(What:="*", SearchDirection:=xlPrevious, SearchOrder:=xlByColumns).Column
For i = LastRow To 1 Step -1
If WorksheetFunction.CountA(Range(Cells(i, 1), Cells(i, LastCol))) = 0 Then
Cells(i, 1).EntireRow.Delete
End If
Next
For i = LastCol To 1 Step -1
If WorksheetFunction.CountA(Range(Cells(1, i), Cells(LastRow, i))) = 0 Then
Cells(1, i).EntireColumn.Delete
End If
Next
End Sub
我认为与原始代码中的等效函数相比,它有两个效率。首先,我们不使用Excel的不可靠的UsedRange属性,而是找到最后一个值,并且只扫描真正使用的范围内的行和列。
其次,工作表计数功能同样只在真正使用的范围内工作-例如,当搜索空白行时,我们只在使用的列范围内查找(而不是.EntireRow
)。
For
循环是反向工作的,因为,例如,每次删除一行时,后续数据的行地址都会更改。向后工作意味着“待处理的数据”的行地址不变。
发布于 2016-11-20 19:36:53
在我看来,最耗时的部分可能是枚举和查找空行和空列。
编辑:
下面是什么:
m_XlWrkSheet.Columns("A:A").SpecialCells(xlCellTypeBlanks).EntireRow.Delete
m_XlWrkSheet.Rows("1:1").SpecialCells(xlCellTypeBlanks).EntireColumn.Delete
在样本数据上测试结果看起来不错,性能更好(从VBA测试,但差异很大)。
更新:
在具有14k行(由样本数据组成)的示例Excel上进行了测试,原始代码约30秒,此版本<1
https://stackoverflow.com/questions/40574084
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