startActivity Qt的，没有什么显示器 [英] startActivity on Qt, nothing displays

问题描述

I codeD像下面。
这似乎显示了Android设置菜单中，但没有出来。
而且我没有看到任何错误或登录了。我不知道打完电话后会发生什么 startActivity（）。

  QAndroidJniObject活性= QAndroidJniObject :: callStaticObjectMethod
                                     （组织/ qtproject / QT5 /安卓/ QtNative
                                      活动，
                                      （）Landroid /应用/活动;）;如果（activity.isValid（））{
    QAndroidJniObject P1 = QAndroidJniObject :: fromString（com.android.settings）;
    QAndroidJniObject P2 = QAndroidJniObject :: fromString（com.android.settings.DevelopmentSettings）;    QAndroidJniObject意图（机器人/内容/意图，（）V）;    如果（p1.isValid（）及＆放大器; p2.isValid（）及＆放大器; intent.isValid（））{         qDebug（）＆所述;＆下; 意图打造确定，startActivity         intent.callObjectMethod（setClassName
                                         （Ljava /朗/字符串; Ljava /朗/字符串;）Landroid /内容/意图;，
         p1.object＆LT; jobject＆GT;（）
         p2.object＆所述; jobject＆GT;（））;
         intent.callObjectMethod（startActivity
                     （Landroid /内容/意图;）V
                     intent.object＆所述; jobject＆GT;（））;
    }
}
 

解决方案

startActivity 是<一个方法href=\"http://developer.android.com/reference/android/app/Activity.html#startActivity(android.content.Intent)\"相对=nofollow>活动类，而不是意向 。因此，它需要在活动对象被调用，而不是意图。

  intent.callObjectMethod（startActivity，（Landroid /内容/意图;）V，intent.object＆LT; jobject＆GT;（））;
 

必须由替换：

  activity.callObjectMethod（startActivity，（Landroid /内容/意图;）V，intent.object＆LT; jobject＆GT;（））;
 

下面是工作code打开Android设置菜单：

  QAndroidJniObject活性= QAndroidJniObject :: callStaticObjectMethod（组织/ qtproject / QT5 /安卓/ QtNative，活动，（）Landroid /应用/活动;）; //活动是有效的
如果（activity.isValid（））
{
    //相当于java的code：意向意图=新的Intent（）;'
    QAndroidJniObject意图（机器人/内容/意图，（）V）;
    如果（intent.isValid（））
    {
        QAndroidJniObject参数1 = QAndroidJniObject :: fromString（com.android.settings）;
        QAndroidJniObject param2的= QAndroidJniObject :: fromString（com.android.settings.DevelopmentSettings）;        如果（param1.isValid（）及＆放大器; param2.isValid（））
        {
            //相当于java的code：'intent.setClassName（com.android.settings，com.android.settings.DevelopmentSettings）;
            intent.callObjectMethod(\"setClassName\",\"(Ljava/lang/String;Ljava/lang/String;)Landroid/content/Intent;\",param1.object<jobject>(),param2.object<jobject>());            //相当于java的code：'startActivity（意向）;'
            activity.callObjectMethod(\"startActivity\",\"(Landroid/content/Intent;)V\",intent.object<jobject>());
        }
    }
}
 

I coded like below. It seems to display the Android Setting menu, but nothing comes out. And I did not see any error or log about it. I don't know what happens after calling the startActivity().

QAndroidJniObject activity = QAndroidJniObject::callStaticObjectMethod
                                     ("org/qtproject/qt5/android/QtNative",
                                      "activity",
                                      "()Landroid/app/Activity;");

if(activity.isValid()){
    QAndroidJniObject p1 = QAndroidJniObject::fromString("com.android.settings");
    QAndroidJniObject p2 = QAndroidJniObject::fromString("com.android.settings.DevelopmentSettings");

    QAndroidJniObject intent("android/content/Intent", "()V");

    if(p1.isValid() && p2.isValid() && intent.isValid()){

         qDebug() << "intent create OK and startActivity";

         intent.callObjectMethod("setClassName",
                                         "(Ljava/lang/String;Ljava/lang/String;)Landroid/content/Intent;",
         p1.object<jobject>(),
         p2.object<jobject>());
         intent.callObjectMethod("startActivity",
                     "(Landroid/content/Intent;)V",
                     intent.object<jobject>());
    }
}

解决方案

startActivity is a method of Activity class, not Intent. So it needs to be called on activity object, not on intent.

intent.callObjectMethod("startActivity", "(Landroid/content/Intent;)V", intent.object<jobject>());

must be replace by:

activity.callObjectMethod("startActivity", "(Landroid/content/Intent;)V", intent.object<jobject>());

Here is the working code to open Android settings menu:

QAndroidJniObject activity = QAndroidJniObject::callStaticObjectMethod("org/qtproject/qt5/android/QtNative", "activity", "()Landroid/app/Activity;");   //activity is valid
if ( activity.isValid() )
{
    // Equivalent to Jave code: 'Intent intent = new Intent();'
    QAndroidJniObject intent("android/content/Intent","()V");
    if ( intent.isValid() )
    {
        QAndroidJniObject param1 = QAndroidJniObject::fromString("com.android.settings");
        QAndroidJniObject param2 = QAndroidJniObject::fromString("com.android.settings.DevelopmentSettings");

        if ( param1.isValid() && param2.isValid() )
        {
            // Equivalent to Jave code: 'intent.setClassName("com.android.settings", "com.android.settings.DevelopmentSettings");'
            intent.callObjectMethod("setClassName","(Ljava/lang/String;Ljava/lang/String;)Landroid/content/Intent;",param1.object<jobject>(),param2.object<jobject>());

            // Equivalent to Jave code: 'startActivity(intent);'
            activity.callObjectMethod("startActivity","(Landroid/content/Intent;)V",intent.object<jobject>());
        }
    }
}

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