未能在 C# 中使用结构数组

Question

我很抱歉这个奇怪的标题，但我无法弄清楚如何表达它:) 我最近转向 C#，目前我正在研究结构。我基本上是一名 C++ 开发人员，在我的 C++ 代码中我完成了以下操作：

typedef struct 
{
String ChannelName;
bool available;
} Voltage_Channel;

Voltage_Channel *m_voltageChannels;

Voltage_Channel redhookChannels[6] = {
{"", false},
{"VDD_IO_AUD",  true},
{"VDD_CODEC_AUD",true},
{"VDD_DAL_AUD", true},
{"VDD_DPD_AUD",  true},
{"VDD_PLL_AUD", true}   
};

if(m_boardName->compareIgnoreCase("S1010012") == 0) //m_BoardName is string
{   
    m_voltageChannels = redhookChannels;
}

我需要在我的 c# 应用程序中执行此操作。我尝试如下，但有问题：

struct VoltageBoardChannel
    {
        public string ChannelName;
        public bool available;            
    };

VoltageBoardChannel[] mVoltageStruct; 

VoltageBoardChannel[] redhookChannels = new VoltageBoardChannel[6]
    {
        new VoltageBoardChannel() { ChannelName = "", available = false},
        new VoltageBoardChannel() { ChannelName = "VDD_IO_AUD", available = true},
        new VoltageBoardChannel() { ChannelName = "VDD_CODEC_AUD", available = true},
        new VoltageBoardChannel() { ChannelName = "VDD_DAL_AUD", available = true},
        new VoltageBoardChannel() { ChannelName = "VDD_DPD_AUD", available = true},
        new VoltageBoardChannel() { ChannelName = "VDD_PLL_AUD", available = true}            
    };

string redhookboardname = "S1010012";
string redhookboardnameCase = "s1010012";

if (redhookboardnameCase.Equals(redhookboardname, stringComparison.InvariantCultureIgnoreCase))
        {
            mVoltageStruct = redhookChannels;
        }

我在哪里做错了？？？ :(

Answer 1

mVoltageStruct 是一个单独的值； redhookChannels 是一个数组。您不能将数组分配给值。但是，您可以查看数组内部：

mVoltageStruct = redhookChannels[0]; // copy the item with index 0, zero-based

但是请注意，除非您有特定的理由（P/Invoke 等）来使用 struct，否则您可能想考虑在那里使用一个类。可变结构通常会导致很多混乱。 C# 中的struct 与 C/C++ 中的struct 的含义不同。

还要注意mVoltageStruct = redhookChannels[0];这一行是复制操作；这并不意味着mVoltageStruct 是指向第零项的引用/指针。在 C# 中有有种方法可以做到这一点，但如果你使用 class 会容易得多；那么你只会复制参考值。

---

按 cmets 编辑：

using System;
using System.Collections.Generic;
class VoltageBoardChannel
{
    public string ChannelName { get; set; }
    public bool IsAvailable { get; set; }
}
static class Program {
    static void Main()
    {
        List<VoltageBoardChannel> selectedChannels = null;

        List <VoltageBoardChannel> redhookChannels = new List<VoltageBoardChannel>
        {
            new VoltageBoardChannel { ChannelName = "", IsAvailable = false},
            new VoltageBoardChannel { ChannelName = "VDD_IO_AUD", IsAvailable = true},
            new VoltageBoardChannel { ChannelName = "VDD_CODEC_AUD", IsAvailable = true},
            new VoltageBoardChannel { ChannelName = "VDD_DAL_AUD", IsAvailable = true},
            new VoltageBoardChannel { ChannelName = "VDD_DPD_AUD", IsAvailable = true},
            new VoltageBoardChannel { ChannelName = "VDD_PLL_AUD", IsAvailable = true}            
        };

        string redhookboardname = "S1010012";
        string redhookboardnameCase = "s1010012";

        // string.Equals(a,b,...) rather than a.Equals(b, ...) avoids
        // potential issues when "a" is null
        if (string.Equals(redhookboardnameCase, redhookboardname,
            StringComparison.InvariantCultureIgnoreCase))
        {
            // set selectedChannels to the **same** list:
            selectedChannels = redhookChannels;

            // or if we wanted a filtered list (same VoltageBoardChannel
            // objects, but a different list instance)
            selectedChannels = redhookChannels.FindAll(x => x.IsAvailable);
        }
    }
}

Answer 2

您只需将mVoltageStruct 声明为数组，而不是对象：

  VoltageBoardChannel[] mVoltageStruct;

然后你可以分配：

 if (redhookboardnameCase.Equals(redhookboardname, StringComparison.InvariantCultureIgnoreCase))
 {
       mVoltageStruct = redhookChannels;
 }