Qt 弹出Toast

1.获取上下文

jobject getApplication(JNIEnv *env) {
    jobject application = nullptr;
    jclass activity_thread_clz = env->FindClass("android/app/ActivityThread");
    if (activity_thread_clz != nullptr) {
        jmethodID currentApplication = env->GetStaticMethodID(
                activity_thread_clz, "currentApplication", "()Landroid/app/Application;");
        if (currentApplication != nullptr) {
            application = env->CallStaticObjectMethod(activity_thread_clz, currentApplication);
        } else {
            printf("Cannot find method: currentApplication() in ActivityThread.");
        }
        env->DeleteLocalRef(activity_thread_clz);
    } else {
        printf("Cannot find class: android.app.ActivityThread");
    }
    return application;
}

2.弹出toast

QAndroidJniObject javaString = QAndroidJniObject::fromString("test toast");
QAndroidJniObject toast = QAndroidJniObject::callStaticObjectMethod("android/widget/Toast", "makeText",
                                                                        "(Landroid/content/Context;Ljava/lang/CharSequence;I)Landroid/widget/Toast;",
                                                                        getApplication(env),
                                                                        javaString.object(),
                                                                        jint(1));
    toast.callMethod<void>("show");

https://blog.csdn.net/lgl1170860350/article/details/51006595
https://schlining.medium.com/a-simple-java-native-interface-jni-example-in-java-and-scala-68fdafe76f5f