there. I am trying to pass a Text Field contents into a database call (mysql). When I look at the field that gets returned from Text->getvalue.(funct) call - I simply do not get the text that was entered into the field - via any of the UTF functions in WXWidgets. I have tried the following:
wxChar buffer = ((wxTextCtrl*)FindWindow(wxID_TITLE))->GetValue().mb_str(wxConvUTF8);
//GooglyGook for whole thing
wxChar buffer = ((wxTextCtrl*)FindWindow(wxID_TITLE))->GetValue().mb_str();
//NULL it fails completely
wxChar buffer = ((wxTextCtrl*)FindWindow(wxID_TITLE))->GetValue().ToUTF8();
//More GOoblygook
wxChar buffer = ((wxTextCtrl*)FindWindow(wxID_TITLE))->GetValue().utf8_str();
//More Gooblygook
message.Printf(_T("The title saved as wxCharBuffer =%s"),buffer.data());
wxMessageBox(message,_("Rivendell"), wxICON_ERROR|wxOK);
The message box is how I am trying to display what is in the wxChar buffer,
but I am running in debug so I can simply look at it during the run and confirm that it is incorrect. Please note that I have tried these wxChar buffer lines one at a time separately (not like they are listed here). Just wanted to show things I had tried.
What is the correct way to do this? The type of characters I am attempting to save in the db looks like:"check Todd 1 乞: 乞丐 qǐgài, 乞求 qǐqiú, 乞讨 qǐtǎo."
The gooblygook output looks like Chineese characters etc.. even in the English part of the field (Check Todd)...
Anyone who has an idea of how to do this please let me know. Thanks...
Tb
I appreciate the help provided, and after trying some things I found an answer.
The correct way to do this seems to be the following: Put the TextCtrl field into a wxString using wx_str(). Then put the wxString into a wxCHarBuffer via toUTF8() function. Then use the data() function of the wxCHarBuffer to pass a char pointer.
Part of my problem stemmed from trying to display what was in those fields via Visual Studio Debugger, and/or wxMessage boxes - so sometimes my conversions were wrong (as noted by the previous poster).
I was able to set the wxString (s) to Unicode characters and have it be handled correctly by the mysql call (i.e. Call would crash before). The chk_title variable returned seems to be correctly encoded into UTF8 and escaped.
Thanks.
Related
I have generated a GeoTiff dataset in-memory using GDALTranslate() with a /vsimem/ filepath. I need access to the buffer for the actual GeoTiff file to put it in a stream for an external API. My understanding is that this should be possible with VSIGetMemFileBuffer(), however I can't seem to get this to return anything other than nullptr.
My code is essentially as follows:
//^^ GDALDataset* srcDataset created somewhere up here ^^
//psOptions struct has "-b 4" and "-of GTiff" settings.
const char* filep = "/vsimem/foo.tif";
GDALDataset* gtiffData = GDALTranslate(filep, srcDataset, psOptions, nullptr);
vsi_l_offset size = 0;
GByte* buf = VSIGetMemFileBuffer(filep, &size, true); //<-- returns nullptr
gtiffData seems to be a real dataset on inspection, it has all the appropriate properties (number of bands, raster size, etc). When I provide a real filesystem location to GDALTranslate() rather than the /vsimem/ path and load it up in QGIS it renders correctly too.
Looking a the source for VSIGetMemFileBuffer(), this should really only be returning nullptr if the file can't be found. This suggests i'm using it incorrectly. Does anyone know what the correct usage is?
Bonus points: Is there a better way to do this (stream the file out)?
Thanks!
I don't know anything about the C++ API. But in Python, the snippet below is what I sometimes use to get the contents of an in-mem file. In my case mainly VRT's but it shouldn't be any different for other formats.
But as said, I don't know if the VSI-api translate 1-on-1 to C++.
from osgeo import gdal
filep = "/vsimem/foo.tif"
# get the file size
stat = gdal.VSIStatL(filep, gdal.VSI_STAT_SIZE_FLAG)
# open file
vsifile = gdal.VSIFOpenL(filep, 'r')
# read entire contents
vsimem_content = gdal.VSIFReadL(1, stat.size, vsifile)
In the case of a VRT the content would be text, shown with something like print(vsimem_content.decode()). For a tiff it would of course be binary data.
I came back to this after putting in a workaround, and upon swapping things back over it seems to work fine. #mmomtchev suggested looking at the CPL_DEBUG output, which showed nothing unusual (and was silent during the actual VSIGetMemFileBuffer call).
In particular, for other reasons I had to put a GDALWarp call in between calling GDALTranslate and accessing the buffer, and it seems that this is what makes the difference. My guess is that GDALWarp is calling VSIFOpenL internally - although I can't find this in the source - and this does some kind of initialisation for VSIGetMemFileBuffer. Something to try for anyone else who encounters this.
Let's try explain my problem. I have to receive a message from a server (programmed in delphi) and do some things with that message in the client side (which is the side I programm, in c++).
Let's say that the message is: "Hello €" that means that I have to work with std::wstring as €(euro sign) needs 2 bytes instead of 1 byte, so knowing that I have made all my work with wstrings and if I set the message it works fine. Now, I have to receive the real one from the server, and here comes the problem.
The person on the server side is sending that message as a string. He uses a EncodeString() function in delphi and he says that he is not gonna change it. So my question is: If I Decode that string into a string in c++, and then I convert it into a wstring, will it work? Or will I have problems and have other message on my string var instead of "Hello €".
If yes, if I can receive that string with no problem, then I have another problem. The function that I have to use to decode the string is void DecodeString(char *buffer, int length);
so normally if you receive a text, you do something like:
char Text[255];
DescodeString(Text, length); // length is a number decoded before
So... can I decode it with no problem and have in Text the "Hello €" message? with that I'll just need to convert it and get the wstring.
Thank you
EDIT:
I'll add another example. If i know that the server is going to send me always a text of length 30 max, in the server they do something like:
EncodeByte(lengthText);
EncodeString(text)
and in the client you do:
int length;
char myText[30];
DecodeByte(length);
DecodeString(myText,length);
and then, you can work with myText as a string lately.
Hope that helps a little more. I'm sorry for not having more information but I'm new in that work and I don't know much more about the server.
EDIT 2
Trying to summarize... The thing is that I have to receive a message and do something with it, with the tool I said I have to decode it. So as de DecodeString() needs a char and I need a wstring, I just need a way to get the data received by the server, decode it with decodeString() and get it into a wstring, but I don't really know if its possible, and if it is, I'm not sure about how to do it and what type of vars use to get it
EDIT 3
Finally! I know what code pages are using. Seems that the client uses the ANSI ones and that the server doesn't, so.. I'll have to tell to the person who does that part to change it to the ANSI ones. Thanks everybody for helping me with my big big ignorance about the existence of code pages.
Since you're using wstring, I guess that you are on Windows (wstring isn't popular on *nix).
If so, you need the Delphi app to send you UTF-16, which you can use in the wstring constructor. Example:
char* input = "\x0ac\x020"; // UTF-16 encoding for euro sign
wchar_t* input2 = reinterpret_cast<wchar_t*>(input);
wstring ws(input2);
If you're Linux/Mac, etc, you need to receive UTF-32.
This method is far from perfect though. There can be pitfalls and edge cases for unicodes beyond 0xffff (chinese, etc). Supporting that probably requires a PhD.
I'm stuck and I need help.
I'm trying to write the correct code for sending back an image file so the web browser can render it. It can send back text/html just fine, but image/* is not working.
You can see the code and the URL is shown below.
https://github.com/MagnusTiberius/iocphttpd/blob/master/iocphttpl/SocketCompletionPortServer.cpp
What the browser is receiving is just a few bytes of image data.
I tried vector, std::string and const char* to set the values of WSABUF, but still the same few bytes are sent over.
Please let know what is the missing piece to make this one work.
Thanks in advance.
Here's your problem:
PerIoData->LPBuffer = _strdup(str.c_str());
The _strdup function only copies up until the first null, so it cannot be used to copy binary data. Consider using malloc and memcpy if you don't want to use the C++ library.
The alternate implementation (in the false branch) is also incorrect, because it saves the data in an object (vc) that goes out of scope before the I/O is completed. You could instead do something like
vector<char> * vc = new vector<char>;
I am learning to code in C using K&R II. I am tired of console apps and decided to get into a GUI environment. Decided to use Code Blocks and wxWidgets. All is installed properly and working. [Windows 7 x86, Code Blocks 13.12, wxWidgets 3.0.0]
I am following the Tutorials on WxWidgets. I am in Tutorial 9. I have it working, finally; there are mistakes in the instructions.
I modified my app to have 2 text boxes and a button vs one text box for the output and one combo box for the input.
Visual C++ environment is totally foreign to me.
For the Button click I would like instead of printing, "O brave new world!\n",
I would like to read what has been entered in textbox1 and print it into textbox2.
The instruction:
wxString Text = TextCtrl1->GetValue();
gets the string that has been entered in textbox1
I have a call to the function
void printg(char *fmt, ...);
I need to know how/what to change the ... argument to so it will passes the wxString Text in the form of an array, I think, to that printg function. I am sure the first thing I need to do is change the Text string to an array, or some way to pass the string itself.
UPDATE 01/08/13 3:35 PM
I cut the code from the Textbox Enter event and pasted it into the ButtonClick event and now I can get the text in Box one to box two.
Now, I need a way to pass the text from textbox 1 to one of my C files, do whatever the exercise is about and pass it back to the click event to be passed to the printg function.
NOTE: I see confusion about printg. I think it is a feature of wxWidgets that lets you print back to a GUI form rather than a console as printf does. It works.
I would put the code on here, but I do not know how. Tried before and get a message about it not being formatted properly.
Thanks for the replies.
Text.ToUTF8().data() gives you const char *
Also if you only want char* instead of const char * you can use const_cast<char *>(Text.ToUTF8().data())
The most convenient thing to do is to use wx equivalents of standard functions, i.e. wxPrintf() in this case, because they allow you to pass wxString (and also std::string, std::wstring, char* and wchar_t*) objects directly, without doing anything special. So you could simply write
wxString s = ...;
wxPrintf("My string is %s\n", s);
OTOH using either printf() or wxPrintf() is generally not very useful in GUI applications, you probably want wxLogMessage() or something similar.
If you have a string: char *str = {"this is my string"};
Then you can use printf() like this:
printf("%s\n", str);
Note, there is no printg() in the C language. And the prototype of the printf() statement allows for multiple arguments to be passed as long as there is a format specifier for each argument. For example, this shows 3 format specifiers, and three arguments:
printf("%s %d %f\n", str, 10, 13.5);
The "..." argument is called the ellipse argument. It's covered in the K&R book, section 7.3 (in my edition anyway). It can have 0 or more arguments in it, as described by the *fmt argument.
If you already have a string ready, just call it like this:
printf("%s",str);
I'm making a 3D environment, and I want to make it so that when you pass the crosshair over an object, some text with its description pops up. But I have this really annoying string format thing in the way.
info.setText(CollMan->getSceneNodeFromScreenCoordinatesBB(blah)->getName());
info being the text object, and getSceneNodeblahblah->getName being the description that I want.
This doesnt work, because setText wants a wchar_t* and getName() provides an irr::c8.
.c_str() doesn't seem to help whatsoever.
How can I get these two to play nice?
If I'm reading the docs correctly you ought to be able to do it by converting it to an irr::core::stringw first as follows:
info.setText( irr::core::stringw( CollMan->getSceneNodeFromScreenCoordinatesBB(blah)->getName() ).c_str() );