/// <summary>
/// 获取类型的列名与属性信息的对应关系
/// </summary>
/// <typeparam name="T"></typeparam>
/// <returns></returns>
private Dictionary <string, PropertyInfo> GetEntityPropertyMapping <T>() where T : new()
{
Dictionary <string, PropertyInfo> dic = new Dictionary <string, PropertyInfo>();
foreach (PropertyInfo prop in typeof(T).GetProperties())
{
Attribute attr = prop.GetCustomAttribute(typeof(ExcelColumnAttribute));
if (attr == null)
{
continue;
}
ExcelColumnAttribute colattr = attr as ExcelColumnAttribute;
dic.Add(colattr.Field, prop);
}
return(dic);
}
public bool IsPropertyAndColumnFit(Type t, IEnumerable <string> cellname)
{
//为了防止传入的类一条ExcelColumnAttribute也没有配置
int attrcount = 0;
foreach (var prop in t.GetProperties())
{
ExcelColumnAttribute attr = prop.GetCustomAttribute(typeof(ExcelColumnAttribute)) as ExcelColumnAttribute;
if (attr == null)
{
continue;
}
attrcount++;
if (!cellname.Any(o => o == attr.Field))
{
return(false);
}
}
return(attrcount == 0 ? false : true);
}
public List <T> ReadData <T>() where T : new()
{
//读取第一页的SHEET，并划分出需要处理的区域来
Worksheet sheet = _workbook.Worksheets[0];
int maxcolumn = 0;
while (sheet.Cells[0, maxcolumn].Type != CellValueType.IsNull)
{
maxcolumn++;
}
;
Range range = sheet.Cells.CreateRange(1, 0, sheet.Cells.Rows.Count - 1, maxcolumn);
//读取实体的变量与列名的对应关系
Dictionary <string, PropertyInfo> dicentity = GetEntityPropertyMapping <T>();
if (dicentity == null || dicentity.Count == 0)
{
throw new Exception("实体没有配置与EXCEL表头对应的列");
}
//读取EXCEL文件中的标题与标题所在的列的INDEX对应的关系`
Dictionary <string, int> dicexcel = GetTableHeaderMapping();
if (dicexcel == null || dicexcel.Count == 0)
{
throw new Exception("导入的EXCEL文件中未发现表头行");
}
//1、使用实体列名与EXCEL列名关系起来，找到实体对应的属性与表格中的列对应
//2、抽取数据
List <T> retdata = new List <T>();
for (int i = 0; i < range.RowCount; i++)
{
T t = new T();
bool isemptyrow = true;
foreach (var key in dicentity.Keys)
{
if (dicexcel.ContainsKey(key))
{
dynamic val = getPropertyValue(dicentity[key], range[i, dicexcel[key]]);
//如果值不为空，则直接将值赋给属性
if (val != null)
{
isemptyrow = false;
}
else
{
//如果根据属性直接取的值为空，则从属性中取出特性中的默认值
//如果默认值中没有定义默认值类型，则直接将默认值赋给属性，否则将先进行转换后再赋值
//这主要是因为特性中只允许赋值常量的数据,decimal和datetime类型的属性不能指定为默认值，所以在这里需要做一个类型转换
ExcelColumnAttribute attr = dicentity[key].GetCustomAttribute(typeof(ExcelColumnAttribute)) as ExcelColumnAttribute;
if (attr.IsRequire)
{
throw new Exception(attr.Field + "不能为空");
}
if (attr != null && attr.Default != null && attr.DefaultType != null)
{
val = Convert.ChangeType(attr.Default, attr.DefaultType);
}
else
{
val = attr.Default;
}
}
dicentity[key].SetValue(t, val);
}
}
if (!isemptyrow)
{
retdata.Add(t);
}
}
return(retdata);
//return default(T);
}
