docs/csharp/whats-new/tutorials/snippets/pattern-objects/InterimSteps.cs - main - aprogrammer/dotnet-docs

docs/csharp/whats-new/tutorials/snippets/pattern-objects/InterimSteps.cs
106 строк3 KB
Tom Dykstra
Update snippets for NRT (#28622)
11 мар 2022, 19:03
11 мар 2022, 19:0313fe3ed
// This file contains versions of the code used in the patterns & objects tutorial
namespace InterimSteps;

// <APIDesign>
public enum WaterLevel
{
    Low,
    High
}
public class CanalLock
{
    // Query canal lock state:
    public WaterLevel CanalLockWaterLevel { get; private set; } = WaterLevel.Low;
    public bool HighWaterGateOpen { get; private set; } = false;
    public bool LowWaterGateOpen { get; private set; } = false;

    // Change the upper gate.
    public void SetHighGate(bool open)
    {
        throw new NotImplementedException();
    }

    // Change the lower gate.
    public void SetLowGate(bool open)
    {
        throw new NotImplementedException();
    }

    // Change water level.
    public void SetWaterLevel(WaterLevel newLevel)
    {
        throw new NotImplementedException();
    }

    public override string ToString() =>
        $"The lower gate is {(LowWaterGateOpen ? "Open" : "Closed")}. " +
        $"The upper gate is {(HighWaterGateOpen ? "Open" : "Closed")}. " +
        $"The water level is {CanalLockWaterLevel}.";
}
// </APIDesign>

public class CanalLockV2
{
    // Query canal lock state:
    public WaterLevel CanalLockWaterLevel { get; private set; } = WaterLevel.Low;
    public bool HighWaterGateOpen { get; private set; } = false;
    public bool LowWaterGateOpen { get; private set; } = false;

    // <FirstImplementation>
    // Change the upper gate.
    public void SetHighGate(bool open)
    {
        HighWaterGateOpen = open;
    }

    // Change the lower gate.
    public void SetLowGate(bool open)
    {
        LowWaterGateOpen = open;
    }

    // Change water level.
    public void SetWaterLevel(WaterLevel newLevel)
    {
        CanalLockWaterLevel = newLevel;
    }
    // </FirstImplementation>
}

public class CanalLockV3
{
    // Query canal lock state:
    public WaterLevel CanalLockWaterLevel { get; private set; } = WaterLevel.Low;
    public bool HighWaterGateOpen { get; private set; } = false;
    public bool LowWaterGateOpen { get; private set; } = false;

    // <SecondImplementation>
    // Change the upper gate.
    public void SetHighGate(bool open)
    {
        if (open && (CanalLockWaterLevel == WaterLevel.High))
            HighWaterGateOpen = true;
        else if (open && (CanalLockWaterLevel == WaterLevel.Low))
            throw new InvalidOperationException("Cannot open high gate when the water is low");
    }
    // </SecondImplementation>

    private void SetHighGateV2(bool open)
    {
#pragma warning disable CS8524 // The switch expression does not handle some values of its input type (it is not exhaustive) involving an unnamed enum value.
        // <ThirdImplementation>
        HighWaterGateOpen = (open, HighWaterGateOpen, CanalLockWaterLevel) switch
        {
            (false, false, WaterLevel.High) => false,
            (false, false, WaterLevel.Low) => false,
            (false, true, WaterLevel.High) => false,
            (false, true, WaterLevel.Low) => false, // should never happen
            (true, false, WaterLevel.High) => true,
            (true, false, WaterLevel.Low) => throw new InvalidOperationException("Cannot open high gate when the water is low"),
            (true, true, WaterLevel.High) => true,
            (true, true, WaterLevel.Low) => false, // should never happen
        };
        // </ThirdImplementation>
#pragma warning restore CS8524 // The switch expression does not handle some values of its input type (it is not exhaustive) involving an unnamed enum value.
    }
}