在 JNI 中返回多维数组 [英] Return multidimensional array in JNI

问题描述

我想将一个已经存在的多维数组从 C++ 返回到 Java 代码.我的代码如下:

I want to return an already existing multidimensional array from C++ to Java code. My code is as below:

int cells [3][3] = {{0}};

int[][]
Java_com_packagename_appname_GameView_addNew(
        JNIEnv *env,
        jobject, int row, int col, int val) {
    cells[row][col] = val;
    return cells;
}

但显然它不起作用.什么是正确的方法?

But obviously it's not working. What would be the proper way?

推荐答案

int cells [3][3] = {{0}};

jobjectArray
Java_com_packagename_appname_GameView_addNew(
        JNIEnv *env,
        jobject, int row, int col, int val) {

    cells[row][col] = val;

    // Get the int array class
    jclass cls = env->FindClass("[I");

    jintArray iniVal = env->NewIntArray(3);
    // Create the returnable jobjectArray with an initial value
    jobjectArray outer = env->NewObjectArray(3,cls, iniVal);

    for (int i = 0; i < 3; i++)
    {
        jintArray inner = env->NewIntArray(3);
        env->SetIntArrayRegion(inner, 0, 3, cells[i]);
        // set inner's values
        env->SetObjectArrayElement(outer, i, inner);
        env->DeleteLocalRef(inner);
    }
    return outer;
}

这篇关于在 JNI 中返回多维数组的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！