c#调用java 怎样处理多态

在C#中调用Java代码并处理多态，可以通过以下步骤实现：

1. 首先，确保你已经将Java类库添加到C#项目中。可以使用Java Native Interface (JNI)或者Java Native Access (JNA)来实现这一点。这里我们以JNI为例。

2. 在Java中定义一个具有多态性的类。例如，我们定义一个Animal类和一个Dog类，Dog类继承自Animal类：

// Animal.java
public class Animal {
    public void makeSound() {
        System.out.println("The animal makes a sound");
    }
}

// Dog.java
public class Dog extends Animal {
    @Override
    public void makeSound() {
        System.out.println("The dog barks");
    }
}

3. 使用javac命令编译Java类，并使用javah命令生成JNI头文件：

javac Animal.java Dog.java
javah -jni Animal

4. 创建一个C#项目，并使用DllImport属性导入Java类库。然后，使用CSharpJavaClass类加载Java类，并调用多态方法：

using System;
using System.Runtime.InteropServices;

class Program
{
    static void Main()
    {
        // 加载Java类库
        IntPtr javaLibrary = LoadJavaLibrary();

        // 创建Java对象
        IntPtr animalHandle = CreateJavaObject(javaLibrary, "Animal");
        IntPtr dogHandle = CreateJavaObject(javaLibrary, "Dog");

        // 调用多态方法
        CallMethod(animalHandle, "makeSound"); // 输出 "The animal makes a sound"
        CallMethod(dogHandle, "makeSound");   // 输出 "The dog barks"

        // 释放资源
        ReleaseJavaObject(animalHandle);
        ReleaseJavaObject(dogHandle);
        FreeJavaLibrary(javaLibrary);
    }

    static IntPtr LoadJavaLibrary()
    {
        return NativeMethods.LoadLibrary("path/to/your/java_library.so");
    }

    static IntPtr CreateJavaObject(IntPtr library, string className)
    {
        return NativeMethods.CreateObject(library, className);
    }

    static void CallMethod(IntPtr objectHandle, string methodName)
    {
        NativeMethods.CallMethod(objectHandle, methodName);
    }

    static void ReleaseJavaObject(IntPtr objectHandle)
    {
        NativeMethods.ReleaseObject(objectHandle);
    }

    static void FreeJavaLibrary(IntPtr library)
    {
        NativeMethods.FreeLibrary(library);
    }
}

public static class NativeMethods
{
    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern IntPtr LoadLibrary(string dllToLoad);

    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern IntPtr CreateObject(IntPtr library, string className);

    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern void CallMethod(IntPtr objectHandle, string methodName);

    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern void ReleaseObject(IntPtr objectHandle);

    [DllImport("kernel32.dll", SetLastError = true)]
    public static extern bool FreeLibrary(IntPtr hModule);
}

注意：请将path/to/your/java_library.so替换为实际的Java类库路径。

通过以上步骤，你可以在C#中调用Java代码并处理多态。