/// <summary>
/// 用于映射Comment的函数
/// </summary>
/// <param name="columnName"></param>
/// <param name="member"></param>
/// <returns></returns>
public ExcelMapper <TEntity> MapCommentFor(string columnName, Expression <Func <TEntity, string> > member)
{
var map = new ExcelMapperSelector <TEntity>()
{
ColumnName = columnName,
ColumnIdx = IndexDict[columnName],
SetValueFunc = null,
};
ParameterExpression objectParameterExpression = Expression.Parameter(typeof(TEntity)), valueParameterExpression = Expression.Parameter(typeof(string));
Expression <Action <TEntity, string> > setValueExpression = Expression.Lambda <Action <TEntity, string> >(
Expression.Block(
Expression.Assign(Expression.Property(objectParameterExpression, ((MemberExpression)member.Body).Member.Name), valueParameterExpression)
), objectParameterExpression, valueParameterExpression
);
Action <TEntity, string> setValue = setValueExpression.Compile();
map.SetValueFunc = (e, val) => {
setValue(e, (string)val);
};
commentSelectors.Add(map);
return(this);
}
/// <summary>
/// 设置映射结果
/// 对每一列，都会调用member= mapFunc(this[columnName])
/// </summary>
/// <typeparam name="TResult"></typeparam>
/// <param name="columnName">对应的Excel列名</param>
/// <param name="member">选择要映射到成员</param>
/// <param name="mapFunc">映射函数，如果为空，就调用ToString</param>
/// <returns></returns>
public ExcelMapper <TEntity> MapFor <TResult>(string columnName, Expression <Func <TEntity, TResult> > member, Func <object, TResult> mapFunc = null)
{
var map = new ExcelMapperSelector <TEntity>()
{
ColumnName = columnName,
ColumnIdx = IndexDict[columnName],
SetValueFunc = null,
};
if (mapFunc == null)
{
ParameterExpression objectParameterExpression = Expression.Parameter(typeof(TEntity)), valueParameterExpression = Expression.Parameter(typeof(string));
Expression <Action <TEntity, string> > setValueExpression = Expression.Lambda <Action <TEntity, string> >(
Expression.Block(
Expression.Assign(Expression.Property(objectParameterExpression, ((MemberExpression)member.Body).Member.Name), valueParameterExpression)
), objectParameterExpression, valueParameterExpression
);
Action <TEntity, string> setValue = setValueExpression.Compile();
map.SetValueFunc = (e, val) => {
setValue(e, val.ToString());
};
}
else
{
ParameterExpression objectParameterExpression = Expression.Parameter(typeof(TEntity)), valueParameterExpression = Expression.Parameter(typeof(TResult));
Expression <Action <TEntity, TResult> > setValueExpression = Expression.Lambda <Action <TEntity, TResult> >(
Expression.Block(
Expression.Assign(Expression.Property(objectParameterExpression, ((MemberExpression)member.Body).Member.Name), valueParameterExpression)
), objectParameterExpression, valueParameterExpression
);
Action <TEntity, TResult> setValue = setValueExpression.Compile();
map.SetValueFunc = (e, val) => {
TResult rst = mapFunc(val);
setValue(e, rst);
};
}
selectors.Add(map);
return(this);
}
