我可以将foreach和LINQ查询合并为一个吗？

Question

我有一个C#代码,如下所示:

foreach (var entry in this.ChangeTracker.Entries()
                     .Where(e => e.Entity is IAuditableTable &&
                                 e.State == EntityState.Added))
{
    IAuditableTable e = (IAuditableTable)entry.Entity;
    e.ModifiedDate = DateTime.Now;
}

这似乎就像foreach和LINQ的结合.sometone告诉我,我可以删除foreach并将其合并到一个LINQ语句中

Answer 1

我建议不要这样做.保持一切尽可能可读:

var auditableTables = this.ChangeTracker.Entries()
                                        .Where(e => e.State == EntityState.Added)
                                        .Select(e => e.Entity)
                                        .OfType<IAuditableTable>();

foreach (var table in auditableTables)
{
    table.ModifiedDate = DateTime.Now;
}

我对编码的经验法则 - 如果你不能像句子一样阅读它,那么它需要修复.

Answer 2

你能做的最好的是

foreach (var entry in from x in this.ChangeTracker.Entries()
                      where x.Entity is IAuditableTable &&
                            x.State == EntityState.Added
                      select (IAuditableTable)x.Entity)
{
    entry.ModifiedDate = DateTime.Now;
}

更新没有查询语法.