如何在LINQ查询中放入条件WHERE子句

Question

我正在尝试在哪里做condition对，我要执行WHERE其他，否则。

var condition = true;

var mast = new List<Master>
{
    new Master{Id = 2, Prop1 = "Default", Prop2 = "Data", Prop3 = 11},
    new Master{Id = 3, Prop1 = "Some", Prop2 = "TestData", Prop3 = 11},
    new Master{Id = 4, Prop1 = "Some", Prop2 = "MoreData", Prop3 = 11},
};

var g = mast.Where(w=> condition ? (x => x.Prop1.ToLower() != "default" || x.Prop2.ToLower() != "data") : true = true).ToList();

上面的代码给我错误，

无法确定条件表达式的类型，因为“ lambda表达式”和“ bool”之间没有隐式转换

Answer 1

只需将条件移至 lambda 中即可：

var g = mast.Where(w => (condition
    ? (w.Prop1.ToLower() != "default" || w.Prop2.ToLower() != "data")
    : true)
).ToList();