Unsolved How Using Multiple ContextProperty

[MrErfan]

hi guys ,
I want to use two Context Property in main.cpp , When I run the program stopped program ,But when the one I use Context Property Program runs correctly
Error : .......Desktop_Qt_5_5_1_MSVC2013_64bit-Debug\debug\Application.exe exited with code 255
my code :

    SqlQueryModel *sqlquerymodel = new SqlQueryModel();
    sqlquerymodel->connecttodb();
    sqlquerymodel->setQuery("SELECT * FROM tbl_user");
    engine.rootContext()->setContextProperty("SqlQueryModel", sqlquerymodel);

    MyClass myclass;
    engine.rootContext()->setContextProperty("MyClass",&myclass);

[jsulm]

Where is this code located?

MyClass myclass;
engine.rootContext()->setContextProperty("MyClass",&myclass);

If it is in a method then myclass is destroyed when the method finishes and your context contains a pointer to something which is already destroyed. Make sure myclass exists during the time the pointer to it is stored in the context.

[MrErfan]

thanks for your response
That is, only once can use Context Property ? So I turned to my two classes into one class

[jsulm]

No, that's not what I said.
The problem was that you stored a pointer to something what was destroyed. As soon as you will try to access it your application will crash.

void SomeClass::someMethod()
{
    MyClass myclass;
    engine.rootContext()->setContextProperty("MyClass",&myclass); <-- here you store pointer to myclass
} <-- here myclass is destroyd, so the pointer you stored in engine is not valid anymore