private static LambdaExpression GetPropertyLambdaExpression(ParameterExpression param, FilterRule rule)
{
string[] propertyNames = rule.Field.Split('.');
Expression propertyAccess = param;
Type type = param.Type;
foreach (string propertyName in propertyNames)
{
PropertyInfo property = type.GetProperty(propertyName);
if (property == null)
{
throw new InvalidOperationException(string.Format(Resources.Filter_RuleFieldInTypeNotFound, rule.Field, type.FullName));
}
type = property.PropertyType;
propertyAccess = Expression.MakeMemberAccess(propertyAccess, property);
}
return(Expression.Lambda(propertyAccess, param));
}
/// <summary>
/// 获取指定查询条件的查询表达式
/// </summary>
/// <typeparam name="T">表达式实体类型</typeparam>
/// <param name="rule">查询条件，如果为null，则直接返回 true 表达式</param>
/// <returns>查询表达式</returns>
public virtual Expression <Func <T, bool> > GetExpression <T>(FilterRule rule)
{
return(FilterHelper.GetExpression <T>(rule));
}
