我正在尝试使用扩展方法，但是该方法用相同的名称定义了两次。
假设jar和import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.*;
import org.apache.poi.ss.util.*;
import org.apache.poi.ss.SpreadsheetVersion;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import org.openxmlformats.schemas.spreadsheetml.x2006.main.CTTableColumn;
class ExcelExpandingTable {
static void addRowToTable(XSSFTable table) {
int lastTableRow = table.getEndCellReference().getRow();
int totalsRowCount = table.getTotalsRowCount();
int lastTableDataRow = lastTableRow - totalsRowCount;
// we will add one row in table data
lastTableRow++;
lastTableDataRow++;
// new table area plus one row
AreaReference newTableArea = new AreaReference(
table.getStartCellReference(),
new CellReference(
lastTableRow,
table.getEndCellReference().getCol()
),
SpreadsheetVersion.EXCEL2007
);
// new table data area plus one row
AreaReference newTableDataArea = new AreaReference(
table.getStartCellReference(),
new CellReference(
lastTableDataRow,
table.getEndCellReference().getCol()
),
SpreadsheetVersion.EXCEL2007
);
XSSFSheet sheet = table.getXSSFSheet();
if (totalsRowCount > 0) {
//if we have totals rows, shift totals rows down
sheet.shiftRows(lastTableDataRow, lastTableRow, 1);
// correcting bug that shiftRows does not adjusting references of the cells
// if row 3 is shifted down, then reference in the cells remain r="A3", r="B3", ...
// they must be adjusted to the new row thoug: r="A4", r="B4", ...
// apache poi 3.17 has done this properly but had have other bugs in shiftRows.
for (int r = lastTableDataRow; r < lastTableRow + 1; r++) {
XSSFRow row = sheet.getRow(r);
if (row != null) {
long rRef = row.getCTRow().getR();
for (Cell cell : row) {
String cRef = ((XSSFCell)cell).getCTCell().getR();
((XSSFCell)cell).getCTCell().setR(cRef.replaceAll("[0-9]", "") + rRef);
}
}
}
// end correcting bug
}
// if there are CalculatedColumnFormulas do filling them to the new row
XSSFRow row = sheet.getRow(lastTableDataRow); if (row == null) row = sheet.createRow(lastTableDataRow);
for (CTTableColumn tableCol : table.getCTTable().getTableColumns().getTableColumnList()) {
if (tableCol.getCalculatedColumnFormula() != null) {
int id = (int)tableCol.getId();
String formula = tableCol.getCalculatedColumnFormula().getStringValue();
XSSFCell cell = row.getCell(id -1); if (cell == null) cell = row.createCell(id -1);
cell.setCellFormula(formula);
}
}
table.setArea(newTableArea);
// correcting bug that Autofilter includes possible TotalsRows after setArea new
// Autofilter must only contain data area
table.getCTTable().getAutoFilter().setRef(newTableDataArea.formatAsString());
// end correcting bug
table.updateReferences();
}
public static void main(String[] args) throws Exception {
try (Workbook workbook = WorkbookFactory.create(new FileInputStream("SAMPLE.xlsx"));
FileOutputStream out = new FileOutputStream("SAMPLE_NEW.xlsx")) {
XSSFSheet sheet = ((XSSFWorkbook)workbook).getSheetAt(0);
XSSFTable table = sheet.getTables().get(0);
addRowToTable(table);
workbook.write(out);
}
}
}
在我的课堂和尝试
A.Extensions.Ext()我想以某种方式定义要使用的方法，但我不知道该怎么做。 感谢您的帮助！
答案 0 :(得分：0)
如果这些类位于不同的命名空间中，则只需要使用您要使用的扩展名方法使用-using ConsoleApp.A;
但是，如果您想明确指定：
假定您有两个带有字符串扩展方法的类
public static class Extension1
{
public static string GetLowerCaseResult(this string str)
{
return str.ToLowerInvariant();
}
}
public static class Extension2
{
public static string GetLowerCaseResult(this string str)
{
return str.ToLowerInvariant();
}
}
要在Main方法中调用它，您必须以这种方式显式指定类和方法
static void Main(string[] args)
{
var str = "QWERTY";
Extension2.GetLowerCaseResult(str);
Console.Read();
}