是否可以将lambda表达式存储为变量并在多个地方使用它。我的db对象的Id为int，UId为uniqueidentifier，在基于Id或UId选择时，我必须编写非常相似的表达式。
Lambda：
var result = await this.Worker.GetRepo<Category>().DbSet
.Include(cat => cat.InfoItems)
.Include(cat => cat.Products)
.ThenInclude(prd => prd.InfoItems)
.Include(cat => cat.Products)
.ThenInclude(prd => prd.GraphicItems)
.ThenInclude(itm => itm.Graphic)
.ThenInclude(gfx => gfx.Items)
.Include(cat => cat.GraphicItems)
.ThenInclude(gfx => gfx.Graphic)
.ThenInclude(gfx => gfx.Items)
.Include(m => m.Modules)
.SingleAsync(cat => cat.Id.Equals(id));
是否有可能：
var expression = .Include(cat => cat.InfoItems)
.Include(cat => cat.Products)
.ThenInclude(prd => prd.InfoItems)
.Include(cat => cat.Products)
.ThenInclude(prd => prd.GraphicItems)
.ThenInclude(itm => itm.Graphic)
.ThenInclude(gfx => gfx.Items)
.Include(cat => cat.GraphicItems)
.ThenInclude(gfx => gfx.Graphic)
.ThenInclude(gfx => gfx.Items)
.Include(m => m.Modules);
然后像这样使用变量：
await this.Worker.GetRepo<Category>().expression.SingleAsync(cat => cat.Id.Equals(id));
await this.Worker.GetRepo<Category>().expression.SingleAsync(cat => cat.UId.Equals(uid));
我知道语法是错误的，这正是我要寻找的。
您可以只创建一个返回的方法IQueryable<Category>。如果您希望用法与示例相同，则可以使用扩展方法：
public static IQueryable<Category> GetExpression(this IQueryable<Category> qry)
{
var expression = qry.Include(cat => cat.InfoItems)
.Include(cat => cat.Products)
.ThenInclude(prd => prd.InfoItems)
.Include(cat => cat.Products)
.ThenInclude(prd => prd.GraphicItems)
.ThenInclude(itm => itm.Graphic)
.ThenInclude(gfx => gfx.Items)
.Include(cat => cat.GraphicItems)
.ThenInclude(gfx => gfx.Graphic)
.ThenInclude(gfx => gfx.Items)
.Include(m => m.Modules);
return expression;
}
然后，您可以按以下方式使用它：
await this.Worker
.GetRepo<Category>()
.GetExpression()
.SingleAsync(cat => cat.UId.Equals(uid));
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