I thought this would be simple but I seem to have myself confused.
I have been learning C++ for some time now and thought I was getting the hang of it. I have moved over to the 'Visual' aspects of it, specifically MFC.
Basically I'm trying to pass a variable from a DLL into a simple static text box on a MFC application.
( This is a plugin for the game rFactor )
This is the code I have in the DLL file ( .hpp )
struct TelemInfoBase
{
float mEngineRPM; // engine RPM
}
And this is the code to put it into the Static text
SetDlgItemText(IDC_DRIVER_NAME, TelemInfoBase::mEngineRPM);
But I'm getting a 'illegal reference to non-static member' error
I assume I have to define a variable for the data to be stored in and then access that variable, but I can't quite get my head around how to do that.
Would anyone care to point me in the correct direction?
Related
I want to delete all the object that is not used now.
I used Visual Studio 2019.
When I search Object Browser, It gets to me some strange struct or class that I modified of name.
For example, first I define a structure as
typedef struct stOutput
{
double dDirtyPrice_CumInt;
double dDM;
//...
double dYield;
} stOutput
Later I changed this definition to
typedef struct stOutput_New
{
double dAI;
//...
long lObservStartDate;
} stOutput_New
However, the object browser shows to me just
stOutput.
There is no stOutput_New.
Also I put my cursor on 'stOutput_New' and push 'F12' then it locates my view some strange area.
There are even no 'stOutput_New'
Now, below picture is describing my real situation
This is 'Class View'
Actually I just use One stOutput, but there are so many stOutput that has same file path
Also below picture is my 'Object Browser'
As you can see the two stOutput have different member variables.
And I changed the name from stOutput to stOutput_new the latter.
But it seems my object browser didn't reflect it.
I tried
Project Unload and Reload it
Organize the code of Solution and Project
Re-Build Solution.
But everything doesn't work.
Please help me
In vs2019, I defined the structure exactly like yours according to your description, and then changed the structure according to your description. My object browser did not have the problem you described. If you are sure that your code does not repeat the definition of structure and other problems, I suggest you reinstall or repair VS.
enter image description here
This is my first question ever posted, so please let me know if there is anything that needs changes in my post :)
I am currently working on a dialog that is supposed to let the user change the background-color for some signal plotting. The "wxColourPickerCtrl" seems to do exactly what I need. Since there are multiple plots/pictures to be manipulated, the ColourPickerCtrls are initialized in a loop with the chosen background color as the default value:
for (const auto& [signalName, signalProperties] : properties)
{
wxColourPickerCtrl* selectBackgroundColor = new wxColourPickerCtrl(this, signalProperties.first, signalProperties.second.backgroundColor, wxDefaultPosition, wxDefaultSize);
}
"this" is an object of type SignalPropertiesDialog, which is directly inherited from wxDialog.
I have left out all the necessary sizer stuff, since it's not relevant for the problem (at least imo). "properties" is structured as follows:
std::map<std::string, std::pair<int, GraphPicture::Properties>> signalProperties_;
where GraphPicture::Properties contains the properties I want to manipulate:
struct Properties
{
wxColour backgroundColor{ *wxWHITE };
wxColour lineColor{ *wxBLACK };
int linewidth_px{ 1 };
bool isShown{ true };
};
The application successfully builds but immediately crashes on startup while generating those color picker objects.
wxIshiko has uploaded multiple tutorials and code snippets as examples for various wxWidgets controls, including the wxColourPickerCtrl. So I downloaded the sample code and tried to run it. Surprisingly, it worked.
While running through the code step by step I noticed the following difference:
The wxColourPickerCtrl is based on wxPickerBase. The wxPickerBase is created by calling the constructor of wxColourPickerCtrl (what I am actually doing in my code). During the construction of the wxPickerBase, the desired color is called by the name wxColourDataBase::FindName(const wxColour& color) const where the wxColourBase itself is instantiated. This is where the difference is:
When running the code snippet by wxIshiko, wxColourDataBase is instantiated correctly including the member m_map of type wxStringToColourHashMap* which is set to be NULL.
When running the code written by myself, wxColourDataBase is not correctly instantiated, and thus the member m_map is not set to be NULL, which leads to to the crash.
I have the feeling that there is nothing wrong with the way I set up the wxColourPickerCtrls. I somehow think there is a difference in the solution properties of the projects. I checked those but was not able to find any relevant differences.
I would really appreciate any hint or help since I am completely stuck on that problem.
Thank you very much in advance and have a good one,
Alex
EDIT:
I attached a screeny of the call stack.
Call stack
When does this code run exactly? If it is done after the library initialization (which would be the case, for example, for any code executed in your overridden wxApp::OnInit()), then wxTheColourDatabase really should be already initialized and what you observe should be impossible, i.e. if it happens it means that something is seriously wrong with your library build (e.g. it doesn't match the compiler options used when compiling your applications).
As always with such "impossible" bugs, starting with a known working code and doing bisection by copying parts of your code into the working version until it stops working will usually end up by finding a bug in your code.
I am working on augmented reality project. So the user should use the Webcam, and to see the captured video with a cube drawn on that frame.
And this is where I get stuck , when I try to use glBindTexture(GL_TEXTURE_2D,texture_background) method, I get error:
(
ArgumentError: argument 2: : wrong type
GLUT Display callback with (),{} failed: returning None argument 2: : wrong type
)
I am completely stuck, have no idea what to do . The project is done in Python 2.7 , am using opencv and PyOpenGl 3.1.0.
You can find code on this link :click here
Thanks in advance.
Interesting error! So I played around with your source code (by the way in the future you should probably just add the code directly to your question instead of as a separate link), and the issue is actually just one of variable scope, not glut or opengl usage. The problem is your texture_background variable does not exist within the scope of the _draw_scene() function. To verify this, simply try calling print texture_background in your _draw_scene() function and you will find it returns None rather than the desired integer texture identifier.
The simple hack-y solution is to just call global texture_background before using it within your _handle_input() function. You will also need to define texture_background = None in the main scope of your program (underneath your ##FOR CUBE FROM OPENGL comment). The same global comment applies for x_axis and z_axis.
That being said, that solution is not really that great. The rigid structure required by GLUT with all of these predefined glut* functions makes it hard to structure code the way you might want to in terms of initializing your app. I would suggest, if you are not forced to use GLUT, to use a more flexible alternative, such as pygame, pysdl2 or pyqt, to create your context instead.
I am attempting to iterate through the forms I have open in my application. I have found the documentation for FMX.Forms.TScreen.Forms, which looks like it can be used to accomplish my goal. However, I am confused on how I am supposed to use it.
At first I tried this in a function within my form's CPP file:
ShowMessage( Forms::TScreen::FormCount );
This produced the error 'Member TScreen::FormCount cannot be used without an object'
I figured that to mean that I need to attempt to access this property from my form, or from the global Application variable. I tried both
this->Forms...
Application->Forms...
and
this->TScreen...
Application->TScreen...
However, neither Forms nor TScreen exist within either of these objects.
How do I go about accessing Forms.TScreen.Forms?
The error gives you a clue:
Member TScreen::FormCount cannot be used without an object
TScreen is a class, not an object. FormCount is not a static member of the class, so you need an object instance of the TScreen class. And such an object is provided for you - the global Screen object:
ShowMessage( Screen->FormCount );
This is stated in the documentation:
FMX.Forms.TScreen
There is a global variable, Screen, of type TScreen, which is instantiated for use by any application with a GUI. Use Screen to obtain information about the current state of the screen in an application.
FMX.Forms.Screen
extern DELPHI_PACKAGE TScreen* Screen;
Here's what works well:
ShowMessage(Screen->FormCount);
Screen is a global object, like Application. The compiler said that FormCount is not static method or smth.
I am trying to use an ActiveX control in my program.
QAxWidget* mAX = new QAxWidget();
mAX->setControl("{XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}");
I know that there is a function:
put_ChannelType(long newValue)
But when I try to execute it:
mAX->dynamicCall("put_ChannelType(long)",2);
mAX->dynamicCall("put_ChannelType(int)",2);
mAX->dynamicCall("put_ChannelType(long)",QVariant(2));
mAX->dynamicCall("put_ChannelType(int)",QVariant(2));
I get:
QAxBase: Error calling IDispatch member put_ChannelType: Bad parameter count
Any idea what is going wrong ?
EDIT:
Weird thing is if I call
mAX->dynamicCall("put_ChannelType()");
I do not get any error message...
EDIT 2:
This also fails (as Constantin suggested)
QList<QVariant> varlist;
varlist << (int)1;
mAX->dynamicCall("put_ChannelType(int)",varlist);
Got this solved using the generateDocumentation() function.
I was using this ActiveX control in another application, but an MFC one.
It seems the function names I was referring to (which were in a machine generated IDispatch wrapper class created by VS) were not the same as the ones Qt listed.
i.e. put_ChannelType is actually SetChannelType...
Maybe this is just a version issue ?
Anyways, important part is knowing that generateDocumentation() can list you all the functions you can call with dynamicCall.
Is it OK?
mAX->dynamicCall("put_ChannelType(const QVariant &)", (long)2);