model-view-controller - Telerik MVC 网格 : Create custom FilterDescriptor based on lambda expression

Question

目前我正在使用这段代码来创建自定义过滤器:

var fName = new FilterDescriptor
{
    Member = "Name",
    MemberType = typeof(string),
    Operator = FilterOperator.Contains,
    Value = name
};

它将像这样添加到 GridCommand:

gridCommand.FilterDescriptors.Add(fName);

但是，想要基于 Linq lambda 表达式创建过滤器，例如:

IQueryable<CD> query = ...
if (!string.IsNullOrWhiteSpace(Artist))
{
    query = query.Where(cd => cd.Artist.Contains(Artist));
}

if (!string.IsNullOrWhiteSpace(Name))
{
    query = query.Where(cd => cd.Name.Contains(Name));
}

如何做到这一点？

Answer 1

在 Telerik 的 QueryableExtensions.cs 文件中，这个扩展方法将完成这项工作:

/// <summary>
/// Filters a sequence of values based on a collection of <see cref="IFilterDescriptor"/>.
/// </summary>
/// <param name="source">The source.</param>
/// <param name="filterDescriptors">The filter descriptors.</param>
/// <returns>
/// An <see cref="IQueryable" /> that contains elements from the input sequence
/// that satisfy the conditions specified by each filter descriptor in <paramref name="filterDescriptors" />.
/// </returns>
public static IQueryable Where(this IQueryable source, IEnumerable<IFilterDescriptor> filterDescriptors) { }