如何在android代码和本机代码之间创建回调? [英] How to create callbacks between android code and native code?
问题描述
我需要在本机代码(c 语言代码)和 Android 代码之间创建回调.我编写了 JNI 函数,用于像这样从 android 调用 C 代码
I have a requirement for creating call backs between native code ( c language code) and Android code .
I wrote JNI functions for calling C code
from the android like this
这里是 JNI 代码
#include <android/log.h>
void initSocket();
#ifdef __cplusplus
extern "C" {
#endif
JNIEXPORT void JNICALL Java_org_pjsip_pjsua_pjsua_1appJNI_initSocket(JNIEnv *jenv, jclass jcls) {
__android_log_write(ANDROID_LOG_INFO, " JNI CODE ", " APP INIT SOCKET");
initSocket();
}
}
C 代码如下所示
void initSocket()
{
/// some more stuff
printf(" initSocket function ");
}
static int worker_thread(void *unused)
{
/// some more stuff
return 0;
}
pj_bool_t on_rx_data1(pj_stun_sock *stun_sock, void *pkt, unsigned pkt_len, const pj_sockaddr_t *src_addr, unsigned addr_len)
{
/// some more stuff
return PJ_TRUE;
}
pj_bool_t on_data_sent1 (pj_stun_sock *stun_sock, pj_ioqueue_op_key_t *send_key, pj_ssize_t sent)
{
/// some more stuff
return PJ_TRUE;
}
pj_bool_t on_status1(pj_stun_sock *stun_sock, pj_stun_sock_op op, pj_status_t status)
{
/// some more stuff
returnsockaddress();
return PJ_TRUE;
}
char* returnsockaddress()
{
/// some more stuff
return ipinttostring(sock_address);
}
char* ipinttostring(unsigned int addr )
{
/// some more stuff
return fullIP;
}
这是我在 C 语言中使用的代码,从 JNI 调用 initSocket()
函数.现在我想在此代码中调用 on_status1
函数时从此 C 代码
创建一个 callback
.这个 on_status1 将在几秒钟内重复,当它被调用时,我想在 android 代码中调用一个函数.
this is the code i am using in C language, calling initSocket()
function from JNI. Now i want to create a callback
from this C code
when on_status1
function called in this code. this on_status1 will repeat in few seconds when ever it's called i want to call a function in android code.
编辑
我试过这样,但没有成功
I tried like this, but not succeeded
JNIEXPORT void JNICALL Java_org_pjsip_pjsua_pjsua_1appJNI_initSocket(JNIEnv *jenv, jobject obj) {
__android_log_write(ANDROID_LOG_INFO, " JNI CODE ", " APP INIT SOCKET");
initSocket();
jclass cls = jenv->GetObjectClass(obj);
jmethodID methodid = env->GetMethodID(cls, "callback", "()V");
if(!methodid) {
return;
}
jenv->CallVoidMethod(obj , methodid);
}
我在 android 代码中被声明为这样的函数.
I was declared function like this in android code.
public static void callback(String value) {
Log.e(TAG, "value:" + value);
}
推荐答案
试试这个:
JNIEXPORT void JNICALL Java_org_pjsip_pjsua_pjsua_1appJNI_initSocket(JNIEnv *jenv, jobject obj) {
__android_log_write(ANDROID_LOG_INFO, " JNI CODE ", " APP INIT SOCKET");
initSocket();
// jclass cls = (*jenv)->GetObjectClass(jenv, obj);
// or something like this :
jclass cls = (*jenv)->FindClass(jenv, "org/pjsip/pjsua/pjsua_appJNI");
jmethodID methodid = (*jenv)->GetStaticMethodID(jenv, cls, "callback", "(Ljava/lang/String;)V");
if(!methodid) {
return;
}
jstring jstr = (*jenv)->NewStringUTF(jenv, "Hello from C");
(*jenv)->CallStaticVoidMethod(jenv, cls, methodid, jstr);
}
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