Question

我有一个dll，它允许我从另一个应用程序（unity3d one）调用UWP FileSavePicker。它工作正常，打开一个选择器，创建一个空文件，其中包含我们为此设置的名称。

但是，当我尝试写入该文件BYTE []时，它不会丢弃任何异常，一切顺利，但文件仍为空。

我确保byte []存在并且不会为空。

我做错了什么？

这是我的源代码：

extern "C" int __stdcall ShowFileSavePickerUsingCallback(const wchar_t* suggestedFileName, BYTE* data, CallbackFunc callback)
{

ComPtr<IInspectable> basePicker;
auto hr = RoActivateInstance(HStringReference(RuntimeClass_Windows_Storage_Pickers_FileSavePicker).Get(), &basePicker);
AssertAndReturnIfFailed(hr);

ComPtr<IFileSavePicker> picker;
hr = basePicker.As(&picker);
AssertAndReturnIfFailed(hr);

hr = picker->put_SuggestedStartLocation(PickerLocationId::PickerLocationId_DocumentsLibrary);
AssertAndReturnIfFailed(hr);

hr = picker->put_SuggestedFileName(HStringReference(suggestedFileName).Get());
AssertAndReturnIfFailed(hr);



ComPtr<IMap<HSTRING, IVector<HSTRING>*>> fileTypeChoices;
 hr = picker->get_FileTypeChoices(&fileTypeChoices);
 AssertAndReturnIfFailed(hr);

 auto txtChoice = Make<StringVector>();
 hr = txtChoice->Append(HStringReference(L".png").Get());
 AssertAndReturnIfFailed(hr);

 boolean replaced;
 hr = fileTypeChoices->Insert(HStringReference(L"PNG file").Get(), txtChoice.Get(), &replaced);
 AssertAndReturnIfFailed(hr);

 ComPtr<IAsyncOperation<StorageFile*>> op;
 hr = picker->PickSaveFileAsync(&op);
 AssertAndReturnIfFailed(hr);

 hr = op->put_Completed(Callback<IAsyncOperationCompletedHandler<StorageFile*>>([callback, data](IAsyncOperation<StorageFile*>* operation, AsyncStatus status) -> HRESULT
 {
  if (status != AsyncStatus::Completed)
  {
   // Figure out the error

   ComPtr<IAsyncInfo> asyncInfo;
   auto hr = operation->QueryInterface(IID_PPV_ARGS(&asyncInfo));
   AssertAndReturnIfFailed(hr);

   HRESULT errorCode;
   hr = asyncInfo->get_ErrorCode(&errorCode);
   AssertAndReturnIfFailed(hr);

   // Do something with errorCode
   // ...
   // ...

   return S_OK;
  }

  ComPtr<IStorageFile> storageFile;
  auto hr = operation->GetResults(&storageFile);
  AssertAndReturnIfFailed(hr);

  ComPtr<IStorageItem> item;
  auto hrr = storageFile->QueryInterface(IID_PPV_ARGS(&item));
  AssertAndReturnIfFailed(hrr);

  HString path;
  hr = item->get_Path(path.GetAddressOf());
  AssertAndReturnIfFailed(hr);

  uint32_t pathLen;
  const wchar_t *pathStr = path.GetRawBuffer(&pathLen);

  SaveDataToAStream(data, storageFile.Get(), callback);

  return S_OK;
 }).Get());
 AssertAndReturnIfFailed(hr);

 return S_OK;
}



int SaveDataToAStream(BYTE* data, IStorageFile*  filePtr, CallbackFunc callback)
{
 __FIAsyncOperation_1_Windows__CStorage__CStreams__CIRandomAccessStream_t * operation;
 __debugbreak();
 auto hr = filePtr->OpenAsync(FileAccessMode::FileAccessMode_ReadWrite, &operation);
 AssertAndReturnIfFailed(hr);

 Event operationCompleted(CreateEvent(nullptr, true, false, nullptr));

 hr = operation->put_Completed(Callback<IAsyncOperationCompletedHandler<IRandomAccessStream*>>
  ([&](IAsyncOperation<IRandomAccessStream*> *pHandler, AsyncStatus status) -> HRESULT
 {
  SetEvent(operationCompleted.Get());
  return S_OK;
 }).Get());

 AssertAndReturnIfFailed(hr);


 WaitForSingleObject(operationCompleted.Get(), INFINITE);

 ComPtr<IRandomAccessStream> stream;

 hr = operation->GetResults(&stream);
 AssertAndReturnIfFailed(hr);

 IOutputStream * outputStream;

 hr = stream->GetOutputStreamAt(0, &outputStream);
 AssertAndReturnIfFailed(hr);

 ComPtr<IDataWriter> dataWriter;

 ComPtr<IDataWriterFactory> dataWriterFactory;

 Windows::Foundation::GetActivationFactory
 (HStringReference(RuntimeClass_Windows_Storage_Streams_DataWriter).Get(), &dataWriterFactory);

 hr = dataWriterFactory->CreateDataWriter(outputStream, &dataWriter);
 AssertAndReturnIfFailed(hr);

 UINT32 byteCount;

 hr = dataWriter->WriteBytes(sizeof(data), data);
 AssertAndReturnIfFailed(hr);

 __FIAsyncOperation_1_UINT32_t * storeOperation;

 Event storeOperationCompleted(CreateEvent(nullptr, true, false, nullptr));

 hr = dataWriter->StoreAsync(&storeOperation);
 AssertAndReturnIfFailed(hr);


 __debugbreak();
 hr = storeOperation->put_Completed(Callback<IAsyncOperationCompletedHandler<UINT32>>
  ([&](IAsyncOperation<UINT32> *pHandler, AsyncStatus status) -> HRESULT
 {
  SetEvent(storeOperationCompleted.Get());


  ComPtr<IStorageItem> item;
  auto hrr = filePtr->QueryInterface(IID_PPV_ARGS(&item));
  AssertAndReturnIfFailed(hrr);

  HString path;
  HRESULT hr = item->get_Path(path.GetAddressOf());
  AssertAndReturnIfFailed(hr);

  uint32_t pathLen;
  const wchar_t *pathStr = path.GetRawBuffer(&pathLen);
  __debugbreak();
  callback(pathStr);

  return S_OK;
 }).Get());
 AssertAndReturnIfFailed(hr);

 WaitForSingleObject(storeOperationCompleted.Get(), INFINITE);

 return 0;
}

UWP C ++ FileSavePicker保存为空

0 个答案: