從對象列表中提取特定的對象屬性到列表中

Question

我有以下接口列表：

List<IInterfaces> instantiatedInterfaces;

IInterfaces具有以下屬性：

List<StandardPort> ListOfPorts { get; }
UInt16 NumberOfPorts { get; }

StandardPort具有屬性：

public Uint16 Side { get; set; }

現在，假設instantiatedInterfaces已正確填充，如何將instantiatedInterfaces接口包含的所有接口的ListOfPorts所有端口（用於特定Side ）提取到List<StandardPort>

我嘗試過的方法（不起作用-返回一個空列表）：

List<StandardPort> foundPorts = instantiatedInterfaces.Select(i => i.ListOfPorts.Where(p => p.side == Left)) as List<StandardPort>;

Answer 1

您正在尋找SelectMany()

List<StandardPort> result = instantiatedInterfaces
             .SelectMany(w => w.ListOfPorts)
             .Where(p => p.side == Left)
             .ToList();

Answer 2

List<StandardPort> ports = instantiatedInterfaces .SelectMany(intf => intf.ListOfPorts) .Where(port => port.side == Left) .ToList();

Answer 3

您可以使用Enumerable.SelectMany將“列表列表”展平為單個列表：

var allPorts = instantiatedInterfaces.SelectMany(iface => iface.ListOfPorts);

然后，您可以使用Enumerable.Where過濾此列表：

var foundPorts = allPorts.Where(port => port.Side == Left).ToList();