Java JNA Write Custom COM Interface of win32 API

Question

我需要编写win32 API的自定义IShellFolder接口。但是我在调用方法ParseDisplayName时遇到问题。jna 的原始有一个错误，其中此方法的 pszDisplayName 参数是字符串，但 win32 api 将 wstring 作为参数。

这是我的代码

String file = "c:\Users\Duchon\Downloads\Baumüller Brno, s.r.o.PS43668.prpkg";
PointerByReference psfDesktopPTR = new PointerByReference();
WinNT.HRESULT hResult = Shell32.INSTANCE.SHGetDesktopFolder(psfDesktopPTR);
if (COMUtils.SUCCEEDED(hResult)) {
IntByReference pcheaten = new IntByReference();
PointerByReference ppidl = new PointerByReference();
IntByReference pdwAttributes = new IntByReference();
IShellFolder psfDesktop = IShellFolder.Converter.PointerToIShellFolder(psfDesktopPTR);
hResult = psfDesktop.ParseDisplayName(null, null, new WString(file), pcheaten, ppidl, pdwAttributes);
if (COMUtils.SUCCEEDED(hResult)) {
}
}

这是我的IShellFolder界面：

public interface IShellFolder {
WinNT.HRESULT ParseDisplayName(WinDef.HWND hwnd, Pointer pbc, WString pszDisplayName, IntByReference pchEaten, PointerByReference ppidl, IntByReference pdwAttributes);
public static class Converter {
public static IShellFolder PointerToIShellFolder(final PointerByReference ptr) {
final Pointer interfacePointer = ptr.getValue();
final Pointer vTablePointer = interfacePointer.getPointer(0);
final Pointer[] vTable = new Pointer[1];
vTablePointer.read(0, vTable, 0, 1);
return new IShellFolder() {
@Override
public WinNT.HRESULT ParseDisplayName(WinDef.HWND hwnd, Pointer pbc, WString pszDisplayName, IntByReference pchEaten, PointerByReference ppidl, IntByReference pdwAttributes) {
Function f = Function.getFunction(vTable[0], Function.ALT_CONVENTION);
return new WinNT.HRESULT(f.invokeInt(new Object[] {interfacePointer, hwnd, pbc, pszDisplayName, pchEaten, ppidl, pdwAttributes }));
}
};
}
}
}

调用方法 ParseDisplay 抛出异常 java.lang.Error： 无效的内存访问。

当我有错误时你能帮助我吗？

谢谢。

Answer 1

你快到了。 通常，自定义现有 JNA 接口的方法是定义自己的接口来扩展它，然后编写自己的方法。 对于单个方法，您基本上就完成了，但是Converter类会生成一个匿名类，您需要完全复制该类。 这应该有效。

public interface MyIShellFolder extends com.sun.jna.platform.win32.COM.IShellFolder {
// Define your own function invocation.
// Since your argument signature includes a WString
// it will be an overloaded version selected when you use the
// WString argument.
WinNT.HRESULT ParseDisplayName(WinDef.HWND hwnd, Pointer pbc, WString pszDisplayName, IntByReference pchEaten,
PointerByReference ppidl, IntByReference pdwAttributes);
// Do the same extending the inner class
public static class Converter extends com.sun.jna.platform.win32.COM.IShellFolder.Converter {
// You are overriding the superclass version of this so you have
// to define the entire method
public static MyIShellFolder PointerToIShellFolder(final PointerByReference ptr) {
final Pointer interfacePointer = ptr.getValue();
final Pointer vTablePointer = interfacePointer.getPointer(0);
final Pointer[] vTable = new Pointer[13];
vTablePointer.read(0, vTable, 0, 13);
return new MyIShellFolder() {
@Override
public WinNT.HRESULT QueryInterface(REFIID byValue, PointerByReference pointerByReference) {
Function f = Function.getFunction(vTable[0], Function.ALT_CONVENTION);
return new WinNT.HRESULT(
f.invokeInt(new Object[] { interfacePointer, byValue, pointerByReference }));
}
@Override
public int AddRef() {
Function f = Function.getFunction(vTable[1], Function.ALT_CONVENTION);
return f.invokeInt(new Object[] { interfacePointer });
}
public int Release() {
Function f = Function.getFunction(vTable[2], Function.ALT_CONVENTION);
return f.invokeInt(new Object[] { interfacePointer });
}
@Override
public WinNT.HRESULT ParseDisplayName(WinDef.HWND hwnd, Pointer pbc, WString pszDisplayName,
IntByReference pchEaten, PointerByReference ppidl, IntByReference pdwAttributes) {
Function f = Function.getFunction(vTable[3], Function.ALT_CONVENTION);
return new WinNT.HRESULT(f.invokeInt(new Object[] { interfacePointer, hwnd, pbc, pszDisplayName,
pchEaten, ppidl, pdwAttributes }));
}
@Override
public WinNT.HRESULT EnumObjects(WinDef.HWND hwnd, int grfFlags, PointerByReference ppenumIDList) {
Function f = Function.getFunction(vTable[4], Function.ALT_CONVENTION);
return new WinNT.HRESULT(
f.invokeInt(new Object[] { interfacePointer, hwnd, grfFlags, ppenumIDList }));
}
public WinNT.HRESULT BindToObject(Pointer pidl, Pointer pbc, REFIID riid, PointerByReference ppv) {
Function f = Function.getFunction(vTable[5], Function.ALT_CONVENTION);
return new WinNT.HRESULT(f.invokeInt(new Object[] { interfacePointer, pidl, pbc, riid, ppv }));
}
@Override
public HRESULT BindToStorage(Pointer pidl, Pointer pbc, REFIID riid, PointerByReference ppv) {
Function f = Function.getFunction(vTable[6], Function.ALT_CONVENTION);
return new WinNT.HRESULT(f.invokeInt(new Object[] { interfacePointer, pidl, pbc, riid, ppv }));
}
@Override
public HRESULT CompareIDs(WinDef.LPARAM lParam, Pointer pidl1, Pointer pidl2) {
Function f = Function.getFunction(vTable[7], Function.ALT_CONVENTION);
return new WinNT.HRESULT(f.invokeInt(new Object[] { interfacePointer, lParam, pidl1, pidl2 }));
}
@Override
public HRESULT CreateViewObject(WinDef.HWND hwndOwner, REFIID riid, PointerByReference ppv) {
Function f = Function.getFunction(vTable[8], Function.ALT_CONVENTION);
return new WinNT.HRESULT(f.invokeInt(new Object[] { interfacePointer, hwndOwner, riid, ppv }));
}
@Override
public HRESULT GetAttributesOf(int cidl, Pointer apidl, IntByReference rgfInOut) {
Function f = Function.getFunction(vTable[9], Function.ALT_CONVENTION);
return new WinNT.HRESULT(f.invokeInt(new Object[] { interfacePointer, cidl, apidl, rgfInOut }));
}
@Override
public HRESULT GetUIObjectOf(WinDef.HWND hwndOwner, int cidl, Pointer apidl, REFIID riid,
IntByReference rgfReserved, PointerByReference ppv) {
Function f = Function.getFunction(vTable[10], Function.ALT_CONVENTION);
return new WinNT.HRESULT(f.invokeInt(
new Object[] { interfacePointer, hwndOwner, cidl, apidl, riid, rgfReserved, ppv }));
}
public WinNT.HRESULT GetDisplayNameOf(Pointer pidl, int flags, STRRET pName) {
Function f = Function.getFunction(vTable[11], Function.ALT_CONVENTION);
return new WinNT.HRESULT(f.invokeInt(new Object[] { interfacePointer, pidl, flags, pName }));
}
@Override
public HRESULT SetNameOf(WinDef.HWND hwnd, Pointer pidl, String pszName, int uFlags,
PointerByReference ppidlOut) {
Function f = Function.getFunction(vTable[12], Function.ALT_CONVENTION);
return new WinNT.HRESULT(
f.invokeInt(new Object[] { interfacePointer, hwnd, pidl, pszName, uFlags, ppidlOut }));
}
// OLD VERSION THAT YOU WANT TO IGNORE BUT MUST DECLARE
@Override
public HRESULT ParseDisplayName(HWND hwnd, Pointer pbc, String pszDisplayName, IntByReference pchEaten,
PointerByReference ppidl, IntByReference pdwAttributes) {
return null;
}
};
}
}
}