自動調整列

//Make all text fit the cells
worksheet.Cells[worksheet.Dimension.Address].AutoFitColumns();

//Autofit with minimum size for the column.
double minimumSize = 10;
worksheet.Cells[worksheet.Dimension.Address].AutoFitColumns(minimumSize);    

//Autofit with minimum and maximum size for the column.
double maximumSize = 50;
worksheet.Cells[worksheet.Dimension.Address].AutoFitColumns(minimumSize, maximumSize);

//optional use this to make all columms just a bit wider, text would sometimes still overflow after AutoFitColumns().
for (int col = 1; col <= worksheet.Dimension.End.Column; col++)
{
    worksheet.Column(col).Width = worksheet.Column(col).Width + 1;
}