无法在Visual Studio窗口中打开文件

Question

I am running Windows 10 and using VS2017. The code below is not opening a file...

    std::ofstream output_file;
    output_file.open("datafile.txt", std::ios::out);
    if (!output_file.is_open())
    {
        std::cout << "This is the whole problem";
    }

Could this be related to permission to writing/reading file and how can I give it the permission.

Answer 1

In UWP app, it can access certain file system locations by default. It can also access additional locations through the file picker , or by declaring capabilities . You can see the File access permissions topic for details.

For your issue, it seems you want to access the file in your app InstalledLocation, as the Application install directory introduction, you can access the file using the following code in C++/WinRT:

Windows::Foundation::IAsyncAction ExampleCoroutineAsync()
{
    Windows::Storage::StorageFile file{
        co_await Windows::Storage::StorageFile::GetFileFromApplicationUriAsync(Windows::Foundation::Uri{L"ms-appx:///datafile.txt"})
    };
    // Process file
}

Or C++:

auto getFileTask = create_task(StorageFile::GetFileFromApplicationUriAsync(ref new Uri("ms-appx:///datafile.txt")));
getFileTask.then([](StorageFile^ file) 
{
    // Process file
});