I was trying to create a client in c++ for a web service using a Service Model Metadata Utility Tool, I have established the communication between the two endpoints, but at the client side I receive a wchar_t*, how can i convert it to a string?
Note: the server side is using encoding of UTF-8.
Use this simple function:
std::string wchar2string(wchar_t* str)
{
std::string mystring;
while( *str )
mystring += (char)*str++;
return mystring;
}
I hope that this function can help you!
You can use std::wstring which has a constructor that takes wchar_t*.
Related
I am using Il2CppInspector to generate scaffolding for a Unity game. I am able to convert System.String (app::String in Il2CppInspector) to std::string using the functions provided below.
How would I reverse this process; how do I convert a std::string to System.String?
helpers.cpp
// Helper function to convert Il2CppString to std::string
std::string il2cppi_to_string(Il2CppString* str) {
std::u16string u16(reinterpret_cast<const char16_t*>(str->chars));
return std::wstring_convert<std::codecvt_utf8_utf16<char16_t>, char16_t>{}.to_bytes(u16);
}
// Helper function to convert System.String to std::string
std::string il2cppi_to_string(app::String* str) {
return il2cppi_to_string(reinterpret_cast<Il2CppString*>(str));
}
In short, I am looking for a function that takes in a std::string and returns an app::String
// Helper function to convert std::string to System.String
app::String string_to_il2cppi(std::string str) {
// Conversion code here
}
The accepted answer is actually wrong, there is no size parameter and copying stops at the first null byte (0x00) according to the MSDN documentation.
The following code fixes these problems and works correctly:
app::String* string_to_il2cppi(const std::string& string)
{
const auto encoding = (*app::Encoding__TypeInfo)->static_fields->utf8Encoding;
const auto managed_string = app::String_CreateStringFromEncoding((uint8_t*)&string.at(0), string.size(), encoding, nullptr);
return managed_string;
}
A quote from djkaty:
To create a string, you cannot use System.String‘s constructors –
these are redirected to icalls that throw exceptions. Instead, you
should use the internal Mono function String.CreateString. This
function has many overloads accepting various types of pointer and
array; an easy one to use accepts a uint16_t* to a Unicode string and
can be called as follows [...]
Export Il2CppInspector with all namespaces, which will give you access to Marshal_PtrToStringAnsi.
app::String* string_to_il2cppi(std::string str) {
return app::Marshal_PtrToStringAnsi((void*)&str, NULL);
}
Limitation: do not attempt to convert a string with null terminators inside of them example:
std::string test = "Hello\0world";
Use BullyWiiPlaza's solution if this is an issue for you.
I am using the casablanca C++ Rest library to make HTTP requests.
The problem is that this gives a utility::string_t string as output and I can't quite find any way to convert this to a classic std::string. Any ideas?
client.request(methods::GET).then([](http_response response)
{
if(response.status_code() == status_codes::OK)
{
string_t s = response.extract_string().get();
}
});
Depending on what platform you are compiling for, the utility::string_t type will be typedef'd to either std::wstring (on Windows) or std::string (on Linux/OSX).
To get a classic utf-8 std::string regardless of platform, take a look at utility::conversions::to_utf8string.
reference documentation
If you see the documentation for C++ REST SDK from github, you'll find a typedef
C++ Rest SDK - utility Namespace Reference
typedef std::string string_t;
So no need to convert it. Both are same types.
On Windows Phone 8.1 there is this define:
typedef std::wstring string_t;
I used this:
string_t toStringT = U("sample");
std::string fromStringT(toStringT.begin(), toStringT.end());
or:
std::string fromStringT(conversions::to_utf8string(toStringT));
I want to add a string into C++ rest sdk json object. I tried
json::value obj;
obj[L"Login"] = json::value::string();
But the problem is this adds only strings as U("str") and not const std::string.
So I can add as
obj[L"Login"] = json::value::string(U("Login"));
but not do as follows:
json::value obj;
string Login= "login";
obj[L"Login"] = json::value::string(Login);
I am using C++ rest sdk 2.8.0.
Try the following type conversion:
json::value obj;
string Login= "login";
std::wstring_convert<std::codecvt_utf8<wchar_t> > converter;
std::wstring uLogin = converter.from_bytes(Login);
obj[L"Login"] = json::value::string(uLogin);
Better switch all your
std::string
to
std::wstring
objects.
cppRest only works with wide strings, so you will end up converting all over the place...
I am using the casablanca C++ Rest library to make HTTP requests.
The problem is that this gives a utility::string_t string as output and I can't quite find any way to convert this to a classic std::string. Any ideas?
client.request(methods::GET).then([](http_response response)
{
if(response.status_code() == status_codes::OK)
{
string_t s = response.extract_string().get();
}
});
Depending on what platform you are compiling for, the utility::string_t type will be typedef'd to either std::wstring (on Windows) or std::string (on Linux/OSX).
To get a classic utf-8 std::string regardless of platform, take a look at utility::conversions::to_utf8string.
reference documentation
If you see the documentation for C++ REST SDK from github, you'll find a typedef
C++ Rest SDK - utility Namespace Reference
typedef std::string string_t;
So no need to convert it. Both are same types.
On Windows Phone 8.1 there is this define:
typedef std::wstring string_t;
I used this:
string_t toStringT = U("sample");
std::string fromStringT(toStringT.begin(), toStringT.end());
or:
std::string fromStringT(conversions::to_utf8string(toStringT));
I run successfully:
Process::Start("C:\\Users\\Demetres\\Desktop\\JoypadCodesApplication.exe");
from a Windows Forms application (visual c++) and as expected, I got 2 programs running simultaneously. My questions is:
Can I pass a string -indicating the file name- to the Process::Start method? I tried:
std::string str="C:\\Users\\Demetres\\Desktop\\JoypadCodesApplication.exe";
Process::Start("%s", str);
but failed. Is this possible?
EDIT:
I think you actually need to marshal to a System::String^ for passing an argument.
You can even marshal directly from a std::string to a System::String^.
///marshal_as<type>(to_marshal)
///marshal_context ctx; ctx.marshal_as<const char *>(to_marshal)
#include <msclr/marshal.h>
#include <msclr/marshal_cppstd.h>
#include <msclr/marshal_atl.h>
using namespace msclr::interop;
using namespace System::Runtime::InteropServices;
Process::Start(marshal_as<String^>(str));
But in this case, you can just use a String^ instead:
String^ str = L"path to file";
Process::Start(str);
When you are working with C++/CLI, you either need to marshal back and forth or use the right data type from the start for how you want to use it.
MSDN: Overview of Marshaling in C++
Process::Start expects a String^ and you are attempting to pass it a std::string. It does not have a variadric version, and does not know what a std::string is. To pass the value from a std::string, you must marshal it:
std::string str("Some Path");
Process::Start(marshal_as<String^>(str));