如何纠正 Native.loadlibrary 错误

Question

这是我的代码。我导入了 JNA 外部 jar，但我无法编译它，因为我收到“SPI INSTANCE = (SPI) Native.loadLibrary("user32", SPI.class, new HashMap() {" 的错误。错误是： “Native类型中的方法loadLibrary(String, Class, Map)不适用于参数(String, Class, new HashMap(){})”

package desktop;
import java.util.HashMap;

import com.sun.jna.Native;
import com.sun.jna.platform.win32.WinDef.UINT_PTR;
import com.sun.jna.win32.*;

public class WallpaperChanger {
    public static void main(String[] args) {
        //supply your own path instead of using this one
        String path = "D:\\stone.png";

        SPI.INSTANCE.SystemParametersInfo(
            new UINT_PTR(SPI.SPI_SETDESKWALLPAPER), 
            new UINT_PTR(0), 
            path, 
            new UINT_PTR(SPI.SPIF_UPDATEINIFILE | SPI.SPIF_SENDWININICHANGE));
        }

        public interface SPI extends StdCallLibrary {

            //from MSDN article
            long SPI_SETDESKWALLPAPER = 20;
            long SPIF_UPDATEINIFILE = 0x01;
            long SPIF_SENDWININICHANGE = 0x02;

            @SuppressWarnings("serial")

            //This is where the error starts:
            SPI INSTANCE = (SPI) Native.loadLibrary("user32", SPI.class, new HashMap<Object, Object>() {
            {
                put(OPTION_TYPE_MAPPER, W32APITypeMapper.UNICODE);
                put(OPTION_FUNCTION_MAPPER, W32APIFunctionMapper.UNICODE);
            }
        });

        boolean SystemParametersInfo(
            UINT_PTR uiAction,
            UINT_PTR uiParam,
            String pvParam,
            UINT_PTR fWinIni
        );
    }
}

Answer 1

试试这个：

    @SuppressWarnings("serial")
    SPI INSTANCE = (SPI) Native.loadLibrary("user32", SPI.class,
            new HashMap<String, Object>() {
                {
                    put(OPTION_TYPE_MAPPER, W32APITypeMapper.UNICODE);
                    put(OPTION_FUNCTION_MAPPER, W32APIFunctionMapper.UNICODE);
                }
            });

答案很简单，方法签名是com.sun.jna.Native#loadLibrary(java.lang.String, java.lang.Class<T>, java.util.Map<java.lang.String,?>)。

您必须传递 java.util.Map<java.lang.String,?> 实例而不是 java.util.Map<java.lang.Object,java.lang.Object> 实例。