通过从qt中的c ++ JNI发送字符串在Android中显示Toast

Question

我正在尝试在C++方面的Java方法调用上显示吐司我已设法调用该方法甚至获取字符串但Toast无法正常工作我已经尝试了几乎所有上下文和所有内容

C++ Side

JavaVMAttachArgs args = { JNI_VERSION_1_6, NULL, NULL };
vm->AttachCurrentThread( &env, &args );
activityConstructor =  env->GetMethodID(activity, "<init>", "()V");
jobject object = env->NewObject(activity, activityConstructor);

toastID = env->GetMethodID(activity, "toast", "(Ljava/lang/String;)V");
qDebug() << "Moving";
jstring message1 = env->NewStringUTF("This comes from jni.");

qDebug()<< "Test" << message1;
env->CallVoidMethod(object, toastID, message1);

Java方面

  public void toast(String message){    

    messageData = message;
Log.d(TAG, message);
new Thread()
{
    public void run()
    {
    esActivity.this.runOnUiThread(new Runnable(){

        public void run(){
            Log.d("Message in UIThread", messageData);
            Toast.makeText(context, messageData, Toast.LENGTH_SHORT).show();
        }
        });
    }
}.start();

}

我在消息中获取字符串值,但此Toast不显示任何内容

任何想法将不胜感激..谢谢

Answer 1

在深入分析我的代码之后,我在代码中找出了问题.希望这个答案对将来的某些人有所帮助.

这是用Java方法在C++中调用JNI的问题.我不得不DetachCurrentThread()在JNI中调用as,本机线程仍然附加到VM并且它保留在本机方法中.改进了正确的代码

JavaVMAttachArgs args = { JNI_VERSION_1_6, NULL, NULL };
vm->AttachCurrentThread( &env, &args );
activityConstructor =  env->GetMethodID(activity, "<init>", "()V");
jobject object = env->NewObject(activity, activityConstructor);

toastID = env->GetMethodID(activity, "toast", "(Ljava/lang/String;)V");
qDebug() << "Moving";
jstring message1 = env->NewStringUTF("This comes from jni.");

qDebug()<< "Test" << message1;
env->CallVoidMethod(object, toastID, message1);
vm->DetachCurrentThread();