tips: Qt5 call android static function

 1.      ?.pro file add:

QT += qml quick androidextras

ANDROID_PACKAGE_SOURCE_DIR = $$PWD/android-sources

OTHER_FILES += \
    android-sources/AndroidManifest.xml \
    android-sources/src/org/qtproject/qmhp/AndroidCodeMhp.java

2.      gen AndroidManifest.xml file; add premission 

AndroidManifest.xml file in "Xml Source" window , make  a change by hand.

 default activity name is "qt.project.qt5.example.bindings.qtActivity" cause qt don't know your java class name, should be change by hand. 

following is a example:

AndroidManifest.xml:

<?xmlversion="1.0"?>

<manifest package="org.qtproject.qmhp" xmlns:android="http://schemas.android.com/apk/res/android" android:versionName="1.0" android:versionCode="1" android:installLocation="auto">

    <application android:hardwareAccelerated="true" android:name="org.qtproject.qt5.android.bindings.QtApplication" android:label="Qmhp" android:icon="@drawable/icon">

        <activity android:configChanges="orientation|uiMode|screenLayout|screenSize|smallestScreenSize|locale|fontScale|keyboard|keyboardHidden|navigation" android:name="org.qtproject.qmhp.AndroidCodeMhp" android:label="@string/app_name" android:screenOrientation="unspecified" android:launchMode="singleTop">

package:  org.qtproject.qmhp

java File name: AndroidCodeMhp.java

java Class : AndroidCodeMhp

3.      qt5 can only call static java function for now.

example java code(get wifi list):

package org.qtproject.qmhp;

import org.qtproject.qt5.android.bindings.QtActivity;
import org.qtproject.qt5.android.bindings.QtApplication;
 

  

 

import java.lang.String;

import java.util.List;

import android.util.Log;

import android.content.Context;

import android.net.wifi.WifiManager;

import android.net.wifi.WifiInfo;

import android.net.wifi.ScanResult;

public class AndroidCodeMhp extends QtActivity

{

    private static AndroidCodeMhp m_instance;

    private static WifiManager m_wifiManager = null;

    private static WifiInfo m_wifiInfo = null;

    private static List<ScanResult>  m_wifiList;

    	public AndroidCodeMhp()

    {

        m_instance = this;

    }

// WIFI

    public static String getWifi(int nu) {

        if (m_wifiManager == null) {

            m_wifiManager = (WifiManager) m_instance.getSystemService(Context.WIFI_SERVICE);

        }

        m_wifiManager.setWifiEnabled(true);

        m_wifiInfo = m_wifiManager.getConnectionInfo();

        return getWifiInfo();

    }

    public static String getWifiList(int nu){

        if (m_wifiManager == null) {

            m_wifiManager = (WifiManager) m_instance.getSystemService(Context.WIFI_SERVICE);

        }

        m_wifiManager.setWifiEnabled(true);

        m_wifiManager.startScan();

         m_wifiList= m_wifiManager.getScanResults();

        if ( m_wifiList.size() == 0){

                    return "n/a";

        }

        String string = new String();

        for (int i = 0; i <  m_wifiList.size(); i++) {

            string += (( m_wifiList.get(i)).toString());

            string += ";";

        }

        return string;

    }

    public static String getWifiInfo() {

        return (m_wifiInfo == null) ? "NULL" : m_wifiInfo.toString();

    }

    ...

}

4.call from qt like following: 

there is a bug, the function must have parameter, other else noting will return. 

the following parameter "22" is not used, but when I use "(V)Ljava/lang/String;" got nothing;

#include <QtAndroidExtras/QAndroidJniObject>

...

    QAndroidJniObject androidString=

    QAndroidJniObject::callStaticObjectMethod(

                "org/qtproject/qmhp/AndroidCodeMhp",

                                              "getWifiList",

                                              "(I)Ljava/lang/String;",

                                              22);

    m_androidWifiData = androidString.toString();

...

qt call android did work,  but must be careful.