wp8使用fopen或来自c ++的CreateFile访问独立存储 [英] wp8 access isolated storage with fopen or CreateFile from c++
问题描述
大家好，
我正在尝试访问复制到WP8仿真器设备的独立存储的文件。使用fopen我只能访问本地安装文件夹。
I'm trying to access files copied to the isolated storage of an WP8 emulator device. With fopen I've only access to the local installation folder.
有没有办法直接从c ++访问isostore文件操作？
Is there a way to access the isostore for file operations directly from c++?
谢谢，
Thanks,
Jürgen
推荐答案
您好Jürgen，
您可以在"适用于Windows Phone 8的Marble Maze示例"中找到C ++ / wp8的隔离存储示例。 （http://code.msdn.microsoft.com/wpapps/Marble-Maze-sample-for-c9f3706b）。
$
在MarbleMaze.cpp中，您有2个具有隔离存储功能：
void MarbleMaze :: SaveState（Windows :: ApplicationModel :: SuspendingDeferral ^ deferral）
void MarbleMaze :: LoadState（）
这是将一个int和一个字符串写入隔离存储文件的示例。 int是保存字符串的长度。
Hi Jürgen,
You can find an example of isolate storage for C++/wp8 in "Marble Maze sample for Windows Phone 8" (http://code.msdn.microsoft.com/wpapps/Marble-Maze-sample-for-c9f3706b).
In MarbleMaze.cpp, you have 2 functions with isolate storage:
void MarbleMaze::SaveState(Windows::ApplicationModel::SuspendingDeferral^ deferral)
void MarbleMaze::LoadState()
This is an example to write an int and a string to an isolate storage file. The int is to save the length of the string.
#include< ppltasks.h>
使用命名空间Windows :: Storage;
using namespace Concurrency;
using namespace Platform;
#include <ppltasks.h>
using namespace Windows::Storage;
using namespace Concurrency;
using namespace Platform;
void FileManager :: WriteFile（String ^ strFile，String ^ strContent）
{
auto folder = ApplicationData :: Current-> LocalFolder;
&NBSP;任务< StorageFile ^> getFileTask（folder-> CreateFileAsync（strFile，CreationCollisionOption :: ReplaceExisting））;
$
//创建一个本地以允许在lambdas之间传递DataReader。
auto writer = std :: make_shared< Streams :: DataWriter ^>（nullptr）;
getFileTask.then（[]（StorageFile ^ file）
{
return file - > OpenAsync（FileAccessMode :: ReadWrite）;
}）。then（[this，writer，strContent]（Streams :: IRandomAccessStream ^ stream）
{
Streams :: DataWriter ^ state = ref new Streams :: DataWriter（stream）;
* writer = state;
无符号整型CODEUNITS =国有> MeasureString（strContent）;
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;国有> WriteUInt32（CODEUNITS）;
state-> WriteString（strContent）;
return state-> StoreAsync（）;
}）。then（[writer]（uint32 count）
{
& nbsp; return（* writer） - > FlushAsync（）;
}）。then（[this，writer]（bool flushed）
{
;删除（*作家）;
}）;
}
$
无效FileManager :: LoadFile（String ^ strFile）
{
auto folder = ApplicationData :: Current-> LocalFolder;
&NBSP;任务< StorageFile ^> getFileTask（folder-> GetFileAsync（strFile））;
$
//创建一个本地以允许在lambdas之间传递DataReader。
auto reader = std :: make_shared< Streams :: DataReader ^>（nullptr）;
getFileTask.then（[this，reader]（任务< StorageFile ^> fileTask）
{
; 尝试
{
; StorageFile ^ file = fileTask.get（）;
$
task< Streams :: IRandomAccessStreamWithContentType ^>（文件 - > OpenReadAsync（）），然后（[读者]（流:: IRandomAccessStreamWithContentType ^流）
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP ; {
* reader = ref new Streams :: DataReader（stream） ;
&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;返回（*读者） - > LoadAsync（的static_cast< UINT32>（于流>大小））;
}）。then（[this，reader]（uint32 b ytesRead）
&NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; {
&NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; Streams :: DataReader ^ state =（* reader）;
&NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; 试试
&NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; {
&NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; unsigned int codeUnits = state-> ReadUInt32（）;
&NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; Platform :: String ^ strContent = state-> ReadString（codeUnits）;
&NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; }
&NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; catch（平台::例外^ e）
&NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; {
&NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; //什么也不做。
&NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; }
&NBSP;&NBSP;&NBSP; &NBSP;&NBSP;&NBSP; }）;;
$
&NBSP;&NBSP;&NBSP; }
&NBSP;&NBSP;&NBSP; catch（平台::例外^ e）
&NBSP;&NBSP;&NBSP; {
&NBSP;&NBSP;&NBSP; }
}）;
}
void FileManager::WriteFile( String^ strFile, String^ strContent )
{
auto folder = ApplicationData::Current->LocalFolder;
task<StorageFile^> getFileTask(folder->CreateFileAsync( strFile, CreationCollisionOption::ReplaceExisting));
// Create a local to allow the DataReader to be passed between lambdas.
auto writer = std::make_shared<Streams::DataWriter^>(nullptr);
getFileTask.then([](StorageFile^ file)
{
return file->OpenAsync(FileAccessMode::ReadWrite);
}).then([this, writer, strContent](Streams::IRandomAccessStream^ stream)
{
Streams::DataWriter^ state = ref new Streams::DataWriter(stream);
*writer = state;
unsigned int codeUnits = state->MeasureString(strContent);
state->WriteUInt32(codeUnits);
state->WriteString(strContent);
return state->StoreAsync();
}).then([writer](uint32 count)
{
return (*writer)->FlushAsync();
}).then([this, writer](bool flushed)
{
delete (*writer);
});
}
void FileManager::LoadFile(String^ strFile)
{
auto folder = ApplicationData::Current->LocalFolder;
task<StorageFile^> getFileTask(folder->GetFileAsync(strFile));
// Create a local to allow the DataReader to be passed between lambdas.
auto reader = std::make_shared<Streams::DataReader^>(nullptr);
getFileTask.then([this, reader](task<StorageFile^> fileTask)
{
try
{
StorageFile^ file = fileTask.get();
task<Streams::IRandomAccessStreamWithContentType^> (file->OpenReadAsync()).then([reader](Streams::IRandomAccessStreamWithContentType^ stream)
{
*reader = ref new Streams::DataReader(stream);
return (*reader)->LoadAsync(static_cast<uint32>(stream->Size));
}).then([this, reader](uint32 bytesRead)
{
Streams::DataReader^ state = (*reader);
try
{
unsigned int codeUnits = state->ReadUInt32();
Platform::String^ strContent = state->ReadString(codeUnits);
}
catch (Platform::Exception^ e)
{
// Do nothing.
}
});;
}
catch (Platform::Exception^ e)
{
}
});
}
问候，
AlanLive
这篇关于wp8使用fopen或来自c ++的CreateFile访问独立存储的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
