C++ project use qml via qrc and doesn't work

[lesner]

here is my code:
main.cpp
@int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QDeclarativeView viewer;

viewer.setSource(QUrl("qrc:/resource/QtJoystickUI.qml"));
viewer.show();
.
.
.

return app.exec();
}@

qrc file:
@<RCC>
<qresource prefix="resource">
<file alias ="QtJoystickUI.qml">QtJoystickUI.qml</file>
<file alias ="Qpositionmoniter">Qpositionmoniter.qml</file>
</qresource>
</RCC>
@

QtJoystickUI:
@Rectangle {
id: base
objectName: "base"
width: 300
height: 400
color: "#00000000"
.
.
.

Qpositionmoniter{
    id: positionmoniter
    x: z_axis_text.x
    y: z_axis_text.y + 50
    width: 200
    height: 200
}

}@

Qpositionmoniter:
@Item {
id: moniterBase
Rectangle {
id: base
color: "gray"
width: parent.width;
height: parent.height
}
Rectangle {
id: position
color: "black"
width: 20
height: 20
radius: width/2
x: base.width/2 - radius
y: base.height/2 - radius
}
}
@

seems the main.cpp can't get the qml file
but if I turn QtJoystickUI into this:
@Rectangle {
id: base
objectName: "base"
width: 300
height: 400
color: "#00000000"
.
.
.
// Qpositionmoniter{
// id: positionmoniter
// x: z_axis_text.x
// y: z_axis_text.y + 50
// width: 200
// height: 200
// }
}@

everything is ok, the app's ui didn't go wrong
I don't know why it happened, can anyone give some help?
thanks for any help!!!

[sierdzio]

Try adding import statement for "Qpositionmoniter", like this:
@
import "qrc:/resource"
@

[andre]

That should not be needed. URL's in QML files are relative.

[SteveKing]

You don't have a .qml extension in the alias for Qpositionmoniter in the QRC file.

[andre]

[quote author="SteveKing" date="1340696771"]You don't have a .qml extension in the alias for Qpositionmoniter in the QRC file. [/quote]
Excellent catch!

[lesner]

[quote author="SteveKing" date="1340696771"]You don't have a .qml extension in the alias for Qpositionmoniter in the QRC file. [/quote]

Thanks a lot!!!
seems I'm too careless

[miroslav]

One way to prevent that from happening again is adding
@
Q_ASSERT(QFile(<resource path>).exists());
@

before setting the URL source. Just make sure to use the same path later :-)