C# 通过反射(Reflection)调用不同名泛型方法

概述

由于工作需要，需要通过数据类型和方法名控制方法走向
用到的数据类型有8种（string,Int16,Int32,Int64,Boolean,Byte,Single,Double）
读取的方法（参数一致，但是数据不同的泛型方法，返回值也是泛型）暂时只有11种，但肯定的是，后续一定会增加

原本计划排列组合，写个88行代码，但是总觉得重复代码过多，且后续维护极其繁琐
例如：新增一个读取方法，需要额外新增8行数据类型选择代码，繁琐暂且不说，主要是容易出现纰漏

网络上一翻搜寻，找到了反射，完美解决了我的问题，现在想把这个反射分享给大家：

排列组合

没错，我最开始就是排列组合

int datatype = default(int) ; // 决定值类型
int GetType = default(int) ; // 决定通过什么方法读取

//类型选择
switch (datatype)
{
    case 2: res[0] += "'" + Convert.ToString(ReadString(dataaddress , datalen , gettype)) + "',"; break;
    case 4: res[0] += Convert.ToString(ReadInt(dataaddress , datalen , gettype)) + ","; break;
    case 6: res[0] += "'" + Convert.ToString(ReadString(dataaddress , datalen , gettype)) + "',"; break;
    case 7: res[0] += Convert.ToString(ReadUshort(dataaddress , datalen , gettype)) + ","; break;
    case 8: res[0] += Convert.ToString(ReadUint(dataaddress , datalen , gettype)) + ","; break;
    case 9: res[0] += Convert.ToString(ReadULong(dataaddress , datalen , gettype)) + ","; break;
    case 10: res[0] += Convert.ToString(ReadInt(dataaddress , datalen , gettype)) + ","; break;
    case 11: res[0] += Convert.ToString(ReadShort(dataaddress , datalen , gettype)) + ","; break;
    case 12: res[0] += Convert.ToString(ReadByte(dataaddress , datalen , gettype)) + ","; break;
    case 13: res[0] += Convert.ToString(ReadFloat(dataaddress , datalen , gettype)) + ","; break;
    case 14: res[0] += Convert.ToString(ReadDouble(dataaddress , datalen , gettype)) + ","; break;
    case 15: res[0] += Convert.ToString(ReadDouble(dataaddress , datalen , gettype)) + ","; break;
    case 20: res[0] += Convert.ToString(ReadBool(dataaddress , datalen , gettype)).ToLower() + ","; break;
    case 31: res[0] += Convert.ToString(ReadLong(dataaddress , datalen , gettype)) + ","; break;
    default: res[0] += Convert.ToString(ReadUshort(dataaddress , datalen , gettype)) + ","; break;
}
//方法选择
//string
public string ReadString(string StartAddress , int Length , int GetType)
{
    switch (GetType)
    {
        case 1: return ModbusTcpRead<string>(StartAddress , Length);
        case 2: return ModbusRtuRead<string>(StartAddress , Length);
        case 3: return ModbusRtuOverTcpRead<string>(StartAddress , Length);
        case 5: return InovanceTcpNetRead<string>(StartAddress , Length);
        case 6: return KeyenceMcNetRead<string>(StartAddress , Length);
        case 7: return MelsecMcNetRead<string>(StartAddress , Length);
        case 8: return OmronFinsNetRead<string>(StartAddress , Length);
        case 9: return PanasonicMcNetRead<string>(StartAddress , Length);
        case 10: return SiemensS7NetRead<string>(StartAddress , Length);
        case 11: return MelsecFxSerialOverTcpRead<string>(StartAddress , Length);
        case 12: return KeyenceMcAsciiNetRead<string>(StartAddress , Length);
        default: return ModbusTcpRead<string>(StartAddress , Length);
    }
}
//Bool
public bool ReadBool(string StartAddress , int Length , int GetType)
{
    switch (GetType)
    {
        case 1: return ModbusTcpRead<bool>(StartAddress , Length);
        case 2: return ModbusRtuRead<bool>(StartAddress , Length);
        case 3: return ModbusRtuOverTcpRead<bool>(StartAddress , Length);
        case 5: return InovanceTcpNetRead<bool>(StartAddress , Length);
        case 6: return KeyenceMcNetRead<bool>(StartAddress , Length);
        case 7: return MelsecMcNetRead<bool>(StartAddress , Length);
        case 8: return OmronFinsNetRead<bool>(StartAddress , Length);
        case 9: return PanasonicMcNetRead<bool>(StartAddress , Length);
        case 10: return SiemensS7NetRead<bool>(StartAddress , Length);
        case 11: return MelsecFxSerialOverTcpRead<bool>(StartAddress , Length);
        case 12: return KeyenceMcAsciiNetRead<bool>(StartAddress , Length);
        default: return ModbusTcpRead<bool>(StartAddress , Length);
    }
}
......(就不全部列出来了，排列组合，懂得吧？)

或许你发现了什么异常，感觉我这么写不太对，应该先控制方法，在控制值类型，但，没区别，还是排列组合，只不过分散了而已

以上代码也不难看出，重复代码非常多，几乎就是copy一份，然后改一下泛型传入

所以我在想，能不能吧参数转换成泛型填入，然后显然不行，后来找到了反射这个法宝

反射（正片开始）

int datatype = default(int) ; // 决定值类型
int GetType = default(int) ; // 决定通过什么方法读取

//方法名
string methodName = "ModbusTcpRead";
switch (gettype)
{
    case 1: methodName = "ModbusTcpRead"; break;
    case 2: methodName = "ModbusRtuRead"; break;
    case 3: methodName = "ModbusRtuOverTcpRead"; break;
    case 5: methodName = "InovanceTcpNetRead"; break;
    case 6: methodName = "KeyenceMcNetRead"; break;
    case 7: methodName = "MelsecMcNetRead"; break;
    case 8: methodName = "OmronFinsNetRead"; break;
    case 9: methodName = "PanasonicMcNetRead"; break;
    case 10: methodName = "SiemensS7NetRead"; break;
    case 11: methodName = "MelsecFxSerialOverTcpRead"; break;
    case 12: methodName = "KeyenceMcAsciiNetRead"; break;
    default: methodName = "ModbusTcpRead"; break;
}
//数据值类型
string type = "System.Int32";
switch (datatype)
{
    case 2: type = "System.String"; break;
    case 4: type = "System.Int32"; break; 
    case 6: type = "System.String"; break;
    case 7: type = "System.UInt16"; break; 
    case 8: type = "System.UInt32"; break; 
    case 9: type = "System.UInt64"; break;
    case 10: type = "System.Int32"; break;
    case 11: type = "System.Int16"; break;
    case 12: type = "System.Byte"; break;
    case 13: type = "System.Single"; break;//float
    case 14: type = "System.Double"; break;
    case 15: type = "System.Double"; break;
    case 20: type = "System.Boolean"; break;
    case 31: type = "System.Int64"; break;
    default: type = "System.UInt16"; break;
}
MethodInfo method = typeof(PLCOper).GetMethod(methodName , BindingFlags.Instance | BindingFlags.Public);
MethodInfo genericMethod = method.MakeGenericMethod(Type.GetType(type , false));
object result = genericMethod.Invoke(this , new object[] { dataaddress , datalen });

//这里有几点要提醒
//1、typeof(PLCOper) 括号里的类名必须是调用方法的父类名
//2、GetMethod 第二个参数，前者用于过滤方法的属性，比如是静态还是非静态，我方法全是非静态，所以需要BindingFlags.Instance 参数
//3、Invoke 第一个参数，如果调用静态方法，传入null就好，实例内的方法，需要传入this
//4、Invoke 第二个参数，是方法的入参

是不是简洁非常多？（看起来没区别或许是因为排列组合我没全部写出来？）

以后新增方法名也只需要在这里改一次就可以了

非常完美！

结束

感谢看到这里。