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。