一个基于NPOI的excel导入导出组件(强类型)
jopen
9年前
一、引子
新进公司被安排处理系统的数据报表任务——对学生的考试成绩进行统计并能导出到excel。虽然以前也有弄过,但感觉不是很好,所以这次狠下心,多花点时间作个让自己满意的插件。
二、适用领域
因为需求是基于学生成绩,可能更多的是按这样的需求去考虑。如下图(请不要计较数据):
三、逻辑
一个excel文件 --> N个工作薄 --> N个数据容器-->N个数据内容
四、类的组成
WorkbookWrapper(抽象类) | excel容器,一个实例代表一个excel文件 |
BuildContext(数据上下文) | 在事件中获取对象的上下文 |
WorkbookExtensions(扩展类) | WorkbookWrapper的扩展,有2个方法,一个保存到本地,一个是http下载 |
XSSFWorkbookBuilder(Excel2007) | 继承WorkbookWrapper提供2007的版本的实现类 |
HSSFWorkbookBuilder(Excel2003) | 同上,版本为2003 |
ExcelModelsPropertyManage | 对生成的的数据结构的管理类 |
ISheetDetail(工作薄接口) | 每一个ISheetDetail都代表一张工作薄(包含一个SheetDataCollection) |
ISheetDataWrapper(内容容器接口) | 每一个ISheetDataWrapper都代表ISheetDetail里的一块内容 |
SheetDataCollection(数据集合) | 内容容器的集合 |
IExcelModelBase(内容模型的基类接口) | ISheetDataWrapper里的内容数据模型均继承此接口(包含一个IExtendedBase集合) |
IExtendedBase(扩展内容接口) | 如上图中的科目1-科目3属于不确定数量的内容均继承此接口 |
IgnoreAttribute(忽略标记) | 不想输出到excel的打上此标记即可 |
CellExtensions(列的扩展) | 格式化列的样式 |
EnumService(枚举服务类) | 输出枚举对象里的DescriptionAttribute特性的值 |
注:标题是依据模型属性的 DisplayName 特性标记来实现的。
五、主要实现类
1 using NPOI.HSSF.UserModel; 2 using NPOI.SS.UserModel; 3 using System; 4 using System.Collections.Generic; 5 using System.IO; 6 using System.Linq; 7 using System.Reflection; 8 using System.ComponentModel; 9 using System.Collections; 10 11 12 namespace ExcelHelper.Operating 13 { 14 public abstract class WorkbookBuilder 15 { 16 protected WorkbookBuilder() 17 { 18 currentWorkbook = CreateWorkbook(); 19 20 buildContext = new BuildContext() { WorkbookBuilder = this, Workbook = currentWorkbook }; 21 } 22 23 public delegate void BuildEventHandler(BuildContext context); 24 25 protected abstract IWorkbook CreateWorkbook(); 26 27 public IWorkbook currentWorkbook; 28 29 private ICellStyle _centerStyle; 30 31 public ICellStyle CenterStyle 32 { 33 get 34 { 35 if (_centerStyle == null) 36 { 37 _centerStyle = currentWorkbook.CreateCellStyle(); 38 39 _centerStyle.Alignment = HorizontalAlignment.Center; 40 41 _centerStyle.VerticalAlignment = VerticalAlignment.Center; 42 } 43 44 return _centerStyle; 45 } 46 } 47 48 private Int32 StartRow = 0;//起始行 49 50 51 private BuildContext buildContext; 52 53 public event BuildEventHandler OnHeadCellSetAfter; 54 55 public event BuildEventHandler OnContentCellSetAfter; 56 57 58 #region DataTableToExcel 59 60 public void Insert(ISheetDetail sheetDetail) 61 { 62 ISheet sheet; 63 64 if (sheetDetail.IsContinue) 65 { 66 sheet = currentWorkbook.GetSheetAt(currentWorkbook.NumberOfSheets - 1); 67 68 StartRow = sheet.LastRowNum + 1; 69 } 70 else 71 { 72 sheet = currentWorkbook.CreateSheet(sheetDetail.SheetName); 73 } 74 75 buildContext.Sheet = sheet; 76 77 sheet = DataToSheet(sheetDetail.SheetDetailDataWrappers, sheet); 78 79 } 80 /// <summary> 81 /// 这里添加数据,循环添加,主要应对由多个组成的 82 /// </summary> 83 /// <param name="sheetDetailDataWrappers"></param> 84 /// <param name="sheet"></param> 85 /// <returns></returns> 86 private ISheet DataToSheet(SheetDataCollection sheetDetailDataWrappers, ISheet sheet) 87 { 88 foreach (var sheetDetailDataWrapper in sheetDetailDataWrappers) 89 { 90 if (sheetDetailDataWrapper.Datas == null || sheetDetailDataWrapper.Datas.Count() == 0) 91 { 92 continue; 93 } 94 95 Type type = sheetDetailDataWrapper.Datas.GetType().GetGenericArguments()[0]; 96 97 if (sheetDetailDataWrapper.HaveTitle) 98 { 99 sheet = SetTitle(sheet, sheetDetailDataWrapper, type); 100 } 101 102 sheet = AddValue(sheet, sheetDetailDataWrapper, type); 103 104 StartRow = StartRow + sheetDetailDataWrapper.EmptyIntervalRow; 105 } 106 107 return sheet; 108 } 109 110 #endregion 111 112 #region 设置值 113 114 private void SetCellValue(ICell cell, object obj) 115 { 116 if (obj == null) 117 { 118 cell.SetCellValue(" "); return; 119 } 120 121 if (obj is String) 122 { 123 cell.SetCellValue(obj.ToString()); return; 124 } 125 126 if (obj is Int32 || obj is Double) 127 { 128 cell.SetCellValue(Math.Round(Double.Parse(obj.ToString()), 2)); return; 129 } 130 131 if (obj.GetType().IsEnum) 132 { 133 cell.SetCellValue(EnumService.GetDescription((Enum)obj)); return; 134 } 135 136 if (obj is DateTime) 137 { 138 cell.SetCellValue(((DateTime)obj).ToString("yyyy-MM-dd HH:mm:ss")); return; 139 } 140 141 if (obj is Boolean) 142 { 143 cell.SetCellValue((Boolean)obj ? "√" : "×"); return; 144 } 145 } 146 147 #endregion 148 149 #region SetTitle 150 private ISheet SetTitle(ISheet sheet, ISheetDataWrapper sheetDetailDataWrapper, Type type) 151 { 152 IRow titleRow = null; 153 154 ICell titleCell = null; 155 156 if (!String.IsNullOrEmpty(sheetDetailDataWrapper.DataName)) 157 { 158 titleRow = sheet.CreateRow(StartRow); 159 160 buildContext.Row = titleRow; 161 162 StartRow++; 163 164 titleCell = SetCell(titleRow, 0, sheetDetailDataWrapper.DataName); 165 166 if (OnHeadCellSetAfter != null) 167 { 168 OnHeadCellSetAfter(buildContext); 169 } 170 } 171 172 IRow row = sheet.CreateRow(StartRow); 173 174 buildContext.Row = row; 175 176 IList<PropertyInfo> checkPropertyInfos = ExcelModelsPropertyManage.CreatePropertyInfos(type); 177 178 int i = 0; 179 180 foreach (PropertyInfo property in checkPropertyInfos) 181 { 182 DisplayNameAttribute dn = property.GetCustomAttributes(typeof(DisplayNameAttribute), false).SingleOrDefault() as DisplayNameAttribute; 183 184 if (dn != null) 185 { 186 SetCell(row, i++, dn.DisplayName); 187 continue; 188 } 189 190 Type t = property.PropertyType; 191 192 if (t.IsGenericType) 193 { 194 if (sheetDetailDataWrapper.Titles == null || sheetDetailDataWrapper.Titles.Count() == 0) 195 { 196 continue; 197 } 198 199 foreach (var item in sheetDetailDataWrapper.Titles) 200 { 201 SetCell(row, i++, item.TypeName); 202 } 203 } 204 } 205 206 if (titleCell != null && i > 0) 207 { 208 titleCell.MergeTo(titleRow.CreateCell(i - 1)); 209 210 titleCell.CellStyle = this.CenterStyle; 211 } 212 213 StartRow++; 214 215 return sheet; 216 } 217 #endregion 218 219 #region AddValue 220 private ISheet AddValue(ISheet sheet, ISheetDataWrapper sheetDetailDataWrapper, Type type) 221 { 222 IList<PropertyInfo> checkPropertyInfos = ExcelModelsPropertyManage.CreatePropertyInfos(type); 223 224 Int32 cellCount = 0; 225 226 foreach (var item in sheetDetailDataWrapper.Datas) 227 { 228 if (item == null) 229 { 230 StartRow++; 231 continue; 232 } 233 234 IRow newRow = sheet.CreateRow(StartRow); 235 236 buildContext.Row = newRow; 237 238 foreach (PropertyInfo property in checkPropertyInfos) 239 { 240 Object obj = property.GetValue(item, null); 241 242 Type t = property.PropertyType; 243 244 if (t.IsGenericType && t.GetGenericTypeDefinition() == typeof(IEnumerable<>)) 245 { 246 var ssd = ((IEnumerable)obj).Cast<IExtendedBase>(); 247 248 if (ssd == null) 249 { 250 continue; 251 } 252 253 foreach (var v in sheetDetailDataWrapper.Titles) 254 { 255 IExtendedBase sv = ssd.Where(s => s.TypeId == v.TypeId).SingleOrDefault(); 256 257 SetCell(newRow, cellCount++, sv.TypeValue); 258 } 259 260 continue; 261 } 262 263 SetCell(newRow, cellCount++, obj); 264 } 265 266 StartRow++; 267 cellCount = 0; 268 } 269 270 return sheet; 271 } 272 273 #endregion 274 275 #region 设置单元格 276 /// <summary> 277 /// 设置单元格 278 /// </summary> 279 /// <param name="row"></param> 280 /// <param name="index"></param> 281 /// <param name="value"></param> 282 /// <returns></returns> 283 private ICell SetCell(IRow row, int index, object value) 284 { 285 ICell cell = row.CreateCell(index); 286 287 SetCellValue(cell, value); 288 289 buildContext.Cell = cell; 290 291 if (OnContentCellSetAfter != null) 292 { 293 OnContentCellSetAfter(buildContext); 294 } 295 296 return cell; 297 } 298 #endregion 299 300 #region ExcelToDataTable 301 302 /// <summary> 303 /// 导入 304 /// </summary> 305 /// <typeparam name="T">具体对象</typeparam> 306 /// <param name="fs"></param> 307 /// <param name="fileName"></param> 308 /// <param name="isFirstRowColumn"></param> 309 /// <returns></returns> 310 public static IEnumerable<T> ExcelToDataTable<T>(Stream fs, bool isFirstRowColumn = false) where T : new() 311 { 312 List<T> ts = new List<T>(); 313 314 Type type = typeof(T); 315 316 IList<PropertyInfo> checkPropertyInfos = ExcelModelsPropertyManage.CreatePropertyInfos(type); 317 318 try 319 { 320 IWorkbook workbook = WorkbookFactory.Create(fs); 321 322 fs.Dispose(); 323 324 ISheet sheet = workbook.GetSheetAt(0); 325 326 if (sheet != null) 327 { 328 IRow firstRow = sheet.GetRow(0); 329 330 int cellCount = firstRow.LastCellNum; //一行最后一个cell的编号 即总的列数 331 332 Int32 startRow = isFirstRowColumn ? 1 : 0; 333 334 int rowCount = sheet.LastRowNum; //行数 335 336 int length = checkPropertyInfos.Count; 337 338 length = length > cellCount + 1 ? cellCount + 1 : length; 339 340 Boolean haveValue = false; 341 342 for (int i = startRow; i <= rowCount; ++i) 343 { 344 IRow row = sheet.GetRow(i); 345 346 if (row == null) continue; //没有数据的行默认是null 347 348 T t = new T(); 349 350 for (int f = 0; f < length; f++) 351 { 352 ICell cell = row.GetCell(f); 353 354 if (cell == null || String.IsNullOrEmpty(cell.ToString())) 355 { 356 continue; 357 } 358 359 object b = cell.ToString(); 360 361 if (cell.CellType == CellType.Numeric) 362 { 363 //NPOI中数字和日期都是NUMERIC类型的,这里对其进行判断是否是日期类型 364 if (HSSFDateUtil.IsCellDateFormatted(cell))//日期类型 365 { 366 b = cell.DateCellValue; 367 } 368 else 369 { 370 b = cell.NumericCellValue; 371 } 372 } 373 374 PropertyInfo pinfo = checkPropertyInfos[f]; 375 376 if (pinfo.PropertyType.Name != b.GetType().Name) //类型不一样的时候,强转 377 { 378 b = System.ComponentModel.TypeDescriptor.GetConverter(pinfo.PropertyType).ConvertFrom(b.ToString()); 379 } 380 381 type.GetProperty(pinfo.Name).SetValue(t, b, null); 382 383 if (!haveValue) 384 { 385 haveValue = true; 386 } 387 } 388 if (haveValue) 389 { 390 ts.Add(t); haveValue = false; 391 } 392 } 393 } 394 395 return ts; 396 } 397 catch (Exception ex) 398 { 399 return null; 400 } 401 } 402 403 #endregion 404 } 405 406 public class BuildContext 407 { 408 public WorkbookBuilder WorkbookBuilder { get; set; } 409 410 public IWorkbook Workbook { get; set; } 411 412 public ISheet Sheet { get; set; } 413 414 public IRow Row { get; set; } 415 416 public ICell Cell { get; set; } 417 418 } 419 } View Code
六、总结
看似简单的逻辑在具体实施还是会碰到的许多问题,尤其是NPOI的数据类型与想要的类型的不符的处理;通用的实现等等,不过幸运的是最后还是出一个满意的版本,这应该算自己第一个面向接口的编程的例子了。
如果你发现什么问题或者有更好的实现方式麻烦留言或者与我联系!