//创建文件using namespace Windows::Storage; MainPage^ rootPage; rootPage = MainPage::Current;create_task(KnownFolders::DocumentsLibrary->CreateFileAsync(rootPage->Filename, CreationCollisionOption::ReplaceExisting)).then([this](StorageFile^ file)    {        rootPage->SampleFile = file;        OutputTextBlock->Text = "The file '" + file->Name + "' was created.";    });

static property Platform::String^ Filename

{

Platform::String^ get()

{

return ref new Platform::String(L"sample.dat");

}

}

property Windows::Storage::StorageFile^ SampleFile

{

Windows::Storage::StorageFile^ get()

{

return sampleFile;

}

void set(Windows::Storage::StorageFile^ value)

{

sampleFile = value;

}

}

2、向文件中写入信息----写Text内容 //另加空间名using namespace concurrency;StorageFile^ file = rootPage->SampleFile;//刚才创建的文件    if (file != nullptr)    {        String^ userContent = InputTextBox->Text;        if (userContent != nullptr && !userContent->IsEmpty())        {            create_task(FileIO::WriteTextAsync(file, userContent)).then([this, file, userContent](task
     
       task)            {                try                {                    task.get();                    OutputTextBlock->Text = "The following text was written to '" + file->Name + "':\n\n" + userContent;                }                catch(COMException^ ex)                {                    rootPage->HandleFileNotFoundException(ex);                }            });        }        else        {            OutputTextBlock->Text = "The text box is empty, please write something and then click 'Write' again.";        }    }
     

//读文件内容-----读text内容

rootPage->ResetScenarioOutput(OutputTextBlock);    StorageFile^ file = rootPage->SampleFile;    if (file != nullptr)    {        String^ userContent = InputTextBox->Text;        if (userContent != nullptr && !userContent->IsEmpty())        {            IBuffer^ buffer = GetBufferFromString(userContent);            create_task(FileIO::WriteBufferAsync(file, buffer)).then([this, file, buffer, userContent](task
      
        task)            {                try                {                    task.get();                    OutputTextBlock->Text = "The following " + buffer->Length.ToString() + " bytes of text were written to '" + file->Name + "':\n\n" + userContent;                }                catch(COMException^ ex)                {                    rootPage->HandleFileNotFoundException(ex);                }            });        }        else        {            OutputTextBlock->Text = "The text box is empty, please write something and then click 'Write' again.";        }    }
      

 

//写Byte流using namespace Windows::Storage::Streams; rootPage->ResetScenarioOutput(OutputTextBlock);    StorageFile^ file = rootPage->SampleFile;    if (file != nullptr)    {        String^ userContent = InputTextBox->Text;        if (userContent != nullptr && !userContent->IsEmpty())        {            create_task(file->OpenTransactedWriteAsync()).then([this, file, userContent](task
     
       task)            {                try                {                    StorageStreamTransaction^ transaction = task.get();                    DataWriter^ dataWriter = ref new DataWriter(transaction->Stream);                    dataWriter->WriteString(userContent);                    create_task(dataWriter->StoreAsync()).then([this, file, dataWriter, transaction, userContent](unsigned int bytesWritten)                    {                        transaction->Stream->Size = bytesWritten; // reset stream size to override the file                        create_task(transaction->CommitAsync()).then([this, file, userContent]()                        {                            OutputTextBlock->Text = "The following text was written to '" + file->Name + "' using a stream:\n\n" + userContent;                        });                    });                }                catch(COMException^ ex)                {                    rootPage->HandleFileNotFoundException(ex);                }            });        }        else        {            OutputTextBlock->Text = "The text box is empty, please write something and then click 'Write' again.";        }    }
     

//读byte流

rootPage->ResetScenarioOutput(OutputTextBlock);

StorageFile^ file = rootPage->SampleFile;

if (file != nullptr)

{

create_task(FileIO::ReadBufferAsync(file)).then([this, file](task<IBuffer^> task)

{

try

{

IBuffer^ buffer = task.get();

DataReader^ dataReader = DataReader::FromBuffer(buffer);

String^ fileContent = dataReader->ReadString(buffer->Length);

OutputTextBlock->Text = "The following " + buffer->Length.ToString() + " bytes of text were read from '" + file->Name + "':\n\n" + fileContent;

}

catch(COMException^ ex)

{

rootPage->HandleFileNotFoundException(ex);

}

});

}