在lambda EX pressions多个Where子句

问题描述：

我有一个简单的lambda EX pression的是这样的：

I have a simple lambda expression that goes something like this:

x=> x.Lists.Include(l => l.Title).Where(l=>l.Title != String.Empty)

现在，如果我想增加一个where子句前pression，比方说， l.InternalName！=的String.Empty 那么会是什么恩pression是什么？

Now, if I want to add one more where clause to the expression, say, l.InternalName != String.Empty then what would the expression be?

答

可

x=> x.Lists.Include(l => l.Title)
     .Where(l => l.Title != String.Empty && l.InternalName != String.Empty)

或

x=> x.Lists.Include(l => l.Title)
     .Where(l => l.Title != String.Empty)
     .Where(l => l.InternalName != String.Empty)

当你看其中，实现，你可以看到它接受 Func键（T，布尔）;这意味着：

When do you look at Where implementation, you can see it accepts a Func(T, bool); that means:

所以，当你

.Where(l => l.InternalName != String.Empty)
//     ^                   ^---------- boolean part
//     |------------------------------ "T" part