I am new in imgui and just installed it with vcpkg and created an application in vs2022 and add these codes:
#include <imgui.h>
using namespace std;
void MySaveFunction()
{
}
int main()
{
ImGui::Text("Hello, world %d", 123);
if (ImGui::Button("Save"))
MySaveFunction();
}
but when I run this application I get this error:
What minimum code do I need to display a window with a button on it?
I searched on the IMGUI website but could not find any simple sample that works.
Dear ImGui provided some detailed examples on how to get started.
Don't be scared to read the code, which might be long and overwhelming if you are new to it.
You basically need to choose a backend, I personally prefer DirectX 11. Then you have to create a window and initialize DirectX. Then create the ImGuiContext - which throws the error for g is nullptr because the context wasn't created, and initialize the backend after that.
Related
I'm working on the WinUI3 desktop application in C++. I was checking how we can get an event when the network to which system is connected to changes. I came across NetworkInformation.NetworkStatusChanged event. But I was not able to find any example of its implementation in C++.
NetworkStatusChangedEventHandler says it has one parameter which is IInspectable object.
i tried
static void NetworkStatusChange(winrt::Windows::Foundation::IInspectable const& sender);
But it gave this error
*\Generated Files\winrt\Windows.Networking.Connectivity.h(2213,81): error C2297: '.*': not valid as right operand has type 'const M'
Can you please help me with help me with how to implement NetworkStatusChanged event in WinUI3 C++ desktop application correctly.
Thank you.
This is how you can do it with C++/WinRT:
add this into the pch.h:
#include <winrt/Windows.Networking.Connectivity.h>
add this somewhere in your code:
// you can instead add a "using namespace Windows::Networking::Connectivity;"
// and use NetworkInformation directly if you prefer
Windows::Networking::Connectivity::NetworkInformation info{};
info.NetworkStatusChanged([=](auto&&...) // sender is not super interesting in this type of event so I've not declared it
{
// do your stuff here
MessageBox(nullptr, L"Something Changed!", L"Network", 0);
});
If you prefer the "raw" C/C++ way, there's an example here: How to detect network change events asynchronously using c++ WinRT
The title is pretty self explanitory: I'm trying to run a process outside of main.cpp using loadfile.cpp and loadfile.h to handle loading and displaying an image. However, Marmalade keeps throwing build errors when I do this.
At a top level, I am looking for a process that will run in main.cpp, make a call to loadfile.cpp and display an image with the code in loadfile.cpp. Ideally:
in main.cpp:
main()
{
//initialize and setup Marmalade stuff
Img* myImg; //create an image object
while (!s3eDeviceCheckQuitRequest()) {
//More Marmalade stuff
myImg->display(); //display said image
}
delete myImg;
return 0;
}
in loadfile.cpp:
#include "loadfile.h"
Img* myImg; //image object
void Img::displayImg()
//display image
and in loadfile.h:
#if !defined(_LOADFILE_H)
#define _LOADFILE_H
class File
{
public:
void displayFile();
};
extern Img* myImg;
#endif //_LOADFILE_H
Can someone point out what I am doing wrong or write a brief script showing me it? Thanks very much!
P.S. I wrote this following the Stage 2 Marmalade looking at what they do with the input.cpp/.h files and Input class. I have the full code available if that would be of help!
You need to mention all of your source files in the mkb, before you can use them in your project. Look for the mkb's source section to add the files. Once done, reload the mkb to find the newly added file in your project automatically.
I'm having a bit of trouble in my attempts to learn WXWidgets. I'm currently trying to work with file Dialogs, and I've got one opening just fine. But I run into trouble whenever I try to apply styles to the window. I get an undeclared identifier for whatever style I use.
My code is as follows (yes, I know, hello world app. I'm experimenting with all the things I need to learn to do before actually making a fully fledged app)
#include "wx/wx.h"
#include "wx/filedlg.h"
#include "HelloWorldApp.h"
IMPLEMENT_APP(HelloWorldApp)
bool HelloWorldApp::OnInit()
{
wxFrame *frame = new wxFrame((wxFrame*) NULL, -1, _T("Hello wxWidgets World"));
wxFileDialog* OpenDialog = new wxFileDialog(frame, _("Choose a file to open"), wxEmptyString, wxEmptyString,
_("Image Files (*.jpg, *.png, *.gif, *.bmp)|*.jpg;*.png;*.gif;*.bmp|Sound Files (*.wav, *.mp3)|*.wav;*.mp3"),
wxFD_MULTIPLE);
frame->CenterOnScreen();
frame->Show(true);
OpenDialog->ShowModal();
SetTopWindow(frame);
return true;
}
It runs just fine without the "wxFD_MULTIPLE" argument. I'm using version 2.8.12 of wxWidgets.
Thanks for reading. I really appreciate any help or guidance anyone can give. Sorry if it's something really obvious I'm missing.
In very old wxWidgets versions (2.6), this style was known as wxMULTIPLE but wxFD_MULTIPLE is definitely available in any 2.8.x version. You should give the (beginning of) the errors you get to allow us to understand what is really going on.
Completely independently, your code is wrong because it contains a memory leak: the dialog must be destroyed as modal dialogs are exceptions to the usual rule that all windows should be allocated on the heap and can be allocated on the stack, i.e. used as simple local variables, see the example in the documentation. Looking at the "dialogs" sample code is also strongly recommended.
I've tried in 2 forums, but I had no luck so far.
So, I am using Qt IDE in order to build my application so as to participate to the Ubuntu Showdown contest. In my application, I've done the following:
void show_app(MainWindow *data)
{
//this works fine:
app_indicator_set_status(appindicator, APP_INDICATOR_STATUS_PASSIVE);
//this crashes the application:
data->show();
}
void MainWindow::make_indicator()
{
if(appindicator){
//appindicator has already been created
return;
}
appindicator = app_indicator_new("Format Junkie Indicator", "formatjunkie", APP_INDICATOR_CATEGORY_APPLICATION_STATUS);
GtkWidget* showapp_option;
GtkWidget* indicatormenu = gtk_menu_new();
GtkWidget* item = gtk_menu_item_new_with_label("Format Junkie main menu");
gtk_menu_item_set_submenu(GTK_MENU_ITEM(item), indicatormenu);
showapp_option = gtk_menu_item_new_with_label("Show App!");
g_signal_connect(showapp_option, "activate", G_CALLBACK(show_app), this);
gtk_menu_shell_append(GTK_MENU_SHELL(indicatormenu), showapp_option);
gtk_widget_show_all(indicatormenu);
app_indicator_set_status(appindicator, APP_INDICATOR_STATUS_ACTIVE);
app_indicator_set_attention_icon(appindicator, "dialog-warning");
app_indicator_set_menu(appindicator, GTK_MENU (indicatormenu));
}
So, basically I am trying to make a simple indicator entry, which, on click, it will hide the indicator and display the application. The indicator can be successfully hidden using the PASSIVE thingy over there, but, during the call data->show();, the application crashes.
Any help on what I am doing wrong would be appreciated! Also, please help me to correct this problem I'm facing (alternatively, I will migrate to the old and good tray icon (it works fine in Ubuntu 12.04, anyway) which I can handle very easily and efficiently)
The callback for the activate signal needs to have the following type:
void callback(GtkMenuItem *, gpointer)
So show_app should be defined like this
void show_app(GtkMenuItem *showapp_option, MainWindow *data)
That should solve your problem.
I am trying to load a Nib from a C++ constructor with Objective C++. I have searched and found enough examples to get some code together but it doesn't display the window. Or any windows for that matter.
Here is an example of the contructor:
JokeSystem::JokeSystem() : fileSystem("/Library/Application Support/Jokes/")
{
try
{
randSystem = new RandSelect<std::string>
(fileSystem.getAllFileContents("%\n"));
}
catch (std::ifstream::failure)
{
NSWindowController * errorWindowControl = [[NSWindowController alloc]
initWithWindowNibName:#"ErrorWindow"];
[errorWindowControl showWindow: nil];
}
}
The purpose of the contructor is to load the contents of a directory into a string. What I am try to do is display the error window when the files fail to open.
ErrorWindow.nib has a single window with an OK button and a NSTextView for the error, I set up a NSWindowController in the nib and connected it to the window.
My only link has been that most examples show this [errorWindowControl showWindow: self];
rather than showWindow: nil but because this is a C++ constructor I it doesn't have self and this doesn't work.
If it matters this contructor is called from the awakeFromNib method of the MainMenu.nib's primary NSObject.
Thanks
A bit of an odd way to approach Cocoa. I would encourage you to step back, learn Objective-C and then write your application with an Objective-C based Cocoa UI layer on top of whatever backing store or model layer you have.
In any case, there isn't anything particularly wrong with that code (save for the odd design).
The first thing to check is the return value of -initWithWindowNibName:. Is errorWindowControl actually non-nil? If it is nil, then the NIB failed to load.
How are you writing the Cocoa application itself? Standard app bundle using Xcode, I hope?
Also, you shouldn't be hardcoding the path to /Library/Application Support/. Actually, your application shouldn't use that directory as the only storage location; many users won't have write access to that directory and won't be able to install your app without administrator access.