Qt on ANDROID:QRC and assets

When using Qt to develop an app for Android, sometimes our app carries some resource files, such as PNG, JPG, and possibly some configuration files, such as XML, where are these files placed?

There are two ways of doing this:

1. Qrc
2. Assets

Let's take a look at each other.

The Qt Resource System

QRC, Qt resource file system, very useful oh. Look at a picture:

Figure 1 QRC

Files you put in the QRC, such as Copy.png, will be compiled into an EXE file (Android app is libapplication.so). These resources are also loaded into memory when you run the app. If you have a large resource, this is a problem.

If you're on an Android platform, you have another option.

Android's assets

Android Project directory has a assets directory, the files placed in the directory will be packaged into the APK, apk in the Android system installation, assets will not be installed in the app directory, note that it is still in the APK, but the app can access the resources in this folder ！

Qt uses this mechanism, realizes the assets virtual file system, our common QFile, Qpixmap, qimage, etc., all can pass "assets:/" The way to access the files within the assets.

With the assets virtual file system, your resource files are not loaded into memory when the program starts, saving resources.

Look at a diagram:

Figure 2 Assets

How do you put that resource file? It's simple, just put it in the Android/assets folder in the Qt project directory. 3:

Figure 3 directory structure using the assets

As long as you do this, Qt compiles the files in the assets into the APK, and then it can be accessed within the C + + code.

Android samples using assets

Refer to the Qt on Android: text-to-detail Hello World process to build a project for Android.

Create a androidmanifest.xml and then devolve a beauty.jpg in the Android/assets directory. Delete the widget.h and widget.cpp of the project. Modify the main.cpp as follows:

#include <QApplication> #include <QLabel> #include <qpixmap>int main (int argc, char *argv[]) {    Qapplication A (argc, argv);    Qlabel label;    Qpixmap pixmap ("assets:/beauty.jpg");    Label.setpixmap (pixmap);    Label.show ();    return a.exec ();}

Compile, run, and you can see Figure 4:

Figure 4 Qt on Android example using assets

OK, this is the end.

Review the Qt on Android series:

Qt on Android: text-to-detail Hello world whole process

Introduction to the development of Qt 5.2 for Android under Windows

Qt for Android deployment process Analysis

QT on Android: output qt Debug information to Logcat

Qt on ANDROID:QT 5.3.0 released for Android improvement instructions

Qt on Android episode 1 (translation)

Qt on Android episode 2 (translation)

Qt on Android episode 3 (translation)

Qt on Android episode 4 (translation)

Qt for Android compiled pure C project

Windows under Qt for Android compiled Android C language executable program

Qt on Android:android SDK installation

Qt on android:http download and JSON parsing

Qt on Android Settings app is named Chinese

QT on Android: let Qt Widgets and QT Quick apply full screen display

Qt on Android: How to adapt to different screen sizes

Qt on Android: Using JNI with third-party jar packages

Introduction to "Qt on Android Core programming"

Qt on ANDROID:QRC and assets