Problems in practicing and running an example

[tomy]

Hi all,

I'm reading this example and did the following works:

1- Using this path I created Main.qml:
file -> New Project -> (File and Classes) Qt -> QML File (Qt Quick 2) -> choose -> Main -> Finish.

2- Typed the code in the image below in main.qml.
3- Ran qmake -project to create .pro file. Then configured the project for all Desktop, Android Arm and Android x86. Then ran the code and it didn't work! :(

Here is the image containing the code and the problem:
https://ibb.co/bwrDqQ

Have I done the project correctly please?

[Fuel]

The Main.qml isnt in your Project Structure. That means you didnt add the File to the .pro File. After adding you need to run qmake again.

[tomy]

@Fuel said in Problems in practicing and running an example:

The Main.qml isnt in your Project Structure. That means you didnt add the File to the .pro File. After adding you need to run qmake again.

By right-clicking on Main in Projects view I tried to add that Main.qml file but I couldn't! How to add it please?
And what is the right method of doing such a example from the beginning please?

[tomy]

How would you do that example by yourself if you were me please?

[mrjj]

Hi
Did you make a QML project ?

You should have the following in main.cpp

#include <QGuiApplication>
#include <QQmlApplicationEngine>

int main(int argc, char *argv[])
{
QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
QGuiApplication app(argc, argv);

QQmlApplicationEngine engine;
engine.load(QUrl(QLatin1String("qrc:/main.qml")));

return app.exec();

}

[tomy]

Thank you. I did like what you said.
Here are my files:
Main.cpp, Mai.qml, Page1.qml and Page1.form.ui.qml.

I get these errors which belong to (the path of) images I think:

qrc:/main.qml:5:1: QML Image: Protocol "c" is unknown
qrc:/main.qml:9:4: QML Image: Protocol "c" is unknown
qrc:/main.qml:16:4: QML Image: Protocol "c" is unknown

[mrjj]

@tomy said in Problems in practicing and running an example:

qrc:/main.qml:5:1: QML Image: Protocol "c" is unknown

its error inside file. something is not right there.
I think they image paths are invalid
https://stackoverflow.com/questions/17610949/protocol-c-is-unknown-error-in-qml
You shall use URL syntax.
or even better. use qres file and the :/file syntax

[tomy]

I tested all three options.
The first mode faced errors.
The second one and third one showed nothing although had no issues!
What is the problem please?

[mrjj]

@tomy
In all cases you user the same path c:/xxxx, so i think paths are the issue.

[tomy]

All images are in the same folder on my Desktop, in this address:
C:\Users\Abbasi\Desktop\images

So how should I give the paths of images to the code please?

[mrjj]

@tomy
Hi
I would move the images to an image folder under the project.
Then i would use a qres file and the ":/" syntax
(like here engine.load(QUrl(QLatin1String("qrc:/main.qml")));)

https://www.youtube.com/watch?v=sWIQIi4lg58
http://www.bogotobogo.com/Qt/Qt5_Resource_Files.php

You can right click an image when inside the qres file and get path there.

[tomy]

Hi,

The purpose is to add a folder (or some files) to the project as resources to use them easier, yeah? OK, I did these:

According to the tuts, I created a Resource file named MyRes like this.
Please note that the Path there is the same path as the project (Main).

I use /MyFiles as the Prefix and add all 4 files, the images (from the image folder on the Desktop).
When adding the files, this message is appeared for all four files. I don't know what to do here.

[mrjj]

@tomy
Hi
Can you right click myres.qrc and choose "Add existing files" , then
select the images. ?

[tomy]

Yes,

And it resulted in this!

[mrjj]

@tomy

That is why i wanted you to move the images to under the project.
The :/Myfile path is not correct. the files are not there...

Anyway, now right click each image and you can copy correct path to use.

[tomy]

The program runs without error but show nothing! Does it work for you please?
What is the problem of this part if it's correct?

You say that you would move the images to an image folder under the project. But how? If you mean using those two tuts, I tried and also posted the error I faced at that time. The current style of adding the path of images (as shown in the screenshot) is rather ugly I think moving the images into a folder under the project would be nicer and better.

[mrjj]

@tomy
Just use the normal explorer to move the files under the project
Try to use the qrc:/ syntax then. Since its compiled into the
.exe i assumed :/ would work.

[tomy]

Just use the normal explorer to move the files under the project

What is this please?

This time I tried the following but no success again.

I copied the images folder into the project folder and used an images.qrc file like this and ran the app using that prefix name. It says it cannot open the files! What is the problem this time?
Where did I go wrong?

[tomy]

Tried again using a new project named Main3 as below, copying the image folder into the project folder.
Here is the content of the files:
main3.pro
main.cpp
images.qrc
main.qml
page1.qml
Page1Form.ui.qml
qtquickcontrols2.conf

The program runs:
Issues window shows nothing.
Application Output shows this:
Starting C:\Users\Abbasi\Documents\QML\Main3\Main3\build-Main3-Desktop_Qt_5_9_0_MinGW_32bit-Debug\debug\Main3.exe...
QML debugging is enabled. Only use this in a safe environment.

Compile Output shows:
12:35:55: Elapsed time: 00:00.

And General Messages shows nothing.

The app shows nothing as the output.
What is the problem? Why can't I run this example successfully?
Why everything with Qt is that complicated and confusing?

[mrjj]

@tomy
You are still having issues with the paths/syntax
The path you use is invalid
Should have the form
qrc:/images/filename.png

Use the right click menu to make sure its correct.

[tomy]

I used, no changes in result! :(

[mrjj]

@tomy
Then I dont know.
Where did you get sample from ?

[tomy]

From here, Digesting an User Interface.

[mrjj]

@tomy
I made a default QML projected
added image folder in project folder and used
Image {
id: root
source: "qrc:/images/test.png"
}

and it loaded image.

So what ever goes wrong in your project, its minor.

[tomy]

I made a default QML projected

Is it different from the "Qt Quick Console 2 Application" project? You yourself told me to create such a project above.

added image folder in project folder and used
Image {
id: root
source: "qrc:/images/test.png"
}

and it loaded image.

So what ever goes wrong in your project, its minor.

Do you do the works just like me? And do your files contain the same thing as mine? And yours works well?!
I tried the example using three projects, Main, Main2 and Main3. None gave me the expected result.

[mrjj]

@tomy said in Problems in practicing and running an example:

Is it different from the "Qt Quick Console 2 Application" project?

No it is such project.
then added image{...} to ApplicationWindow

ApplicationWindow {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")

    Image {
        id: root
        source: "qrc:/images/test.png"
    }
.....

test project
https://www.dropbox.com/s/kfkjb7c8dldvtr2/myqml.zip?dl=0

[tomy]

ApplicationWindow {
visible: true
width: 640
height: 480

This part solved the issue.

test project
https://www.dropbox.com/s/kfkjb7c8dldvtr2/myqml.zip?dl=0

Thanks.

[mrjj]

@tomy
Ah so the sample had no window or something like that ?

[tomy]

@mrjj
No unfortunately! Didn't you take a look at the website I offered?
I fear how I go on reading that book if its next examples are that vague! :-(

[mrjj]

@tomy
Yep. seems like a good book.
If you read it all, i think it will give lots of insights.
When you then know the classes and overall architecture, it should be easier to google
for other examples if needed.

[tomy]

@mrjj
Honestly I'm reading the official Qt book (in chapter 5 now) and that book too. So I expect to encounter many problems (since I'm teaching myself the both books without any tutor). but since there are useful websites and very helpful forums (like here), I think I can cope with them, although with difficulties.