/// <summary>
/// 合并单元格
/// </summary>
/// <param name="fromCell">起始单元格</param>
/// <param name="toCell">终止单元格</param>
/// <param name="isExpand">扩充模式</param>
public static void Merge(this NPOI.SS.UserModel.ICell fromCell, NPOI.SS.UserModel.ICell toCell,
bool isExpand = false)
{
if (!fromCell.Sheet.Equals(toCell.Sheet))
{
throw new OfficeException("单元格不在同一个工作表上");
}
var sheet = fromCell.Sheet;
var fromRange = fromCell.GetRangeInfo();
var toRange = toCell.GetRangeInfo();
var firstRowIndex = Math.Min(fromRange.FirstRow, toRange.FirstRow);
var firstColIndex = Math.Min(fromRange.FirstCol, toRange.FirstCol);
var lastRowIndex = Math.Max(fromRange.LastRow, toRange.LastRow);
var lastColIndex = Math.Max(fromRange.LastCol, toRange.LastCol);
var regionInfoList = sheet.GetMergedRegionInfos(firstRowIndex, lastRowIndex, firstColIndex, lastColIndex, false);
foreach (var regionInfo in regionInfoList)
{
if (isExpand)
{
firstRowIndex = Math.Min(firstRowIndex, regionInfo.FirstRow);
firstColIndex = Math.Min(firstColIndex, regionInfo.FirstCol);
lastRowIndex = Math.Max(lastRowIndex, regionInfo.LastRow);
lastColIndex = Math.Max(lastColIndex, regionInfo.LastCol);
}
sheet.RemoveMergedRegion(regionInfo.Index);
}
var region = new CellRangeAddress(firstRowIndex, lastRowIndex, firstColIndex, lastColIndex);
fromCell.Sheet.AddMergedRegion(region);
}