JNA - 无法从本地函数调用回调函数
问题描述:
我正在使用JNA来调用dll文件的函数。JNA - 无法从本地函数调用回调函数
上述功能之一需要一个指针指向一个回调函数
// Dll function
void MyFunction (*CallBackFnName);
下面是Java
import com.sun.jna.Callback;
import com.sun.jna.Library;
import com.sun.jna.Pointer;
public interface Dll extends Library {
interface CallBackFnName extends Callback {
void callback(Pointer dataBuffer, int dataLen);
}
public void MyFunction(Dll.CallBackFnName fn);
public int StartReading(short arg1, short arg2);
}
的JNA代理接口根据该DLL的API,使指针后a 回拨功能至功能MyFunction(* CallBackFnName),无论何时致电StartReading()函数会将数据发送到回调函数。
当我试图做到这一点,它不是调用我的回调函数。它也没有抛出任何异常。
下面是从我调用函数的代码:
import com.sun.jna.Native;
import com.sun.jna.Pointer;
public class Start {
private static Dll dll = (Dll) Native.loadLibrary("MyDll", Dll.class);
private static Dll.CallBackFnName fn = new Dll.CallBackFnName() {
@Override
public void callback(Pointer dataBuffer, int dataLen) {
System.err.println("Callback function is called successfully");
}
};
public static void main(String[] args) throws InterruptedException {
dll.MyFunction(fn); //passed the pointer to the callback function
short arg1 = 0;
short arg2 = 0;
dll.StartReading(arg1, arg2));
Thread.sleep(10 * 1000);
}
}
运行上面的代码后,我收到的控制台上执行以下操作:
DeviceAttach: received and accepted attach for vendor id 0x3eb, product id 0x2ffd, interface 0, device handle 0x037825E8
Main Menu (active Dev/Prod/Interface/Alt. Setting: 0x3eb/0x2ffd/0/0)
Read FailReadWritePipesMenu: WDU_Transfer(control receive) failed: error 0x2000000e ("
Read Fail")
Read FailReadWritePipesMenu: WDU_Transfer(control receive) failed: error 0x2000000e ("
Read Fail")
Read FailReadWritePipesMenu: WDU_Transfer(control receive) failed: error 0x2000000e ("
Read Fail")
Transferred 0 bytes
0 0
答
不知道你还是需要的答案,但其他人谁都有这个问题, 我有这个问题before.I不得不创建一个匿名类本身(使用上面的例子),
dll.myfunc(new Dll.CallBackFnName() {
@Override
public void callback(Pointer dataBuffer, int dataLen) {
System.err.println("Callback function is called successfully");
} });
这对我有效。虽然我无法解释为什么。