Android的NDK开发(4)————JNI数据结构之JNINativeMethod

2022-10-19 13:26:40

转至：http://blog.csdn.net/conowen/article/details/7524744

1、JNINativeMethod 结构体的官方定义

typedef struct {

const char* name;

const char* signature;

void* fnPtr;

} JNINativeMethod;

第一个变量name是Java中函数的名字。

第二个变量signature，用字符串是描述了Java中函数的参数和返回值

第三个变量fnPtr是函数指针，指向native函数。前面都要接 (void *)

第一个变量与第三个变量是对应的，一个是java层方法名，对应着第三个参数的native方法名字

更多内容请查看之前博文：http://blog.csdn.net/conowen/article/details/7521340

示例：

/*

 * 由于gMethods[]是一个<名称，函数指针>对照表，在程序执行时，

 * 可多次调用registerNativeMethods()函数来更换本地函数的指针，

 * 从而达到弹性调用本地函数的目的。

 *具体可以参看http://blog.csdn.net/conowen/article/details/7521340

 */

static JNINativeMethod gMethods[] = {

    {"setDataSource",       "(Ljava/lang/String;)V",            (void *)com_media_ffmpeg_FFMpegPlayer_setDataSource},

    {"_setVideoSurface",    "(Landroid/view/Surface;)V",        (void *)com_media_ffmpeg_FFMpegPlayer_setVideoSurface},

    {"prepare",             "()V",                              (void *)com_media_ffmpeg_FFMpegPlayer_prepare},

    {"_start",              "()V",                              (void *)com_media_ffmpeg_FFMpegPlayer_start},

    {"_stop",               "()V",                              (void *)com_media_ffmpeg_FFMpegPlayer_stop},

    {"getVideoWidth",       "()I",                              (void *)com_media_ffmpeg_FFMpegPlayer_getVideoWidth},

    {"getVideoHeight",      "()I",                              (void *)com_media_ffmpeg_FFMpegPlayer_getVideoHeight},

    {"seekTo",              "(I)V",                             (void *)com_media_ffmpeg_FFMpegPlayer_seekTo},

    {"_pause",              "()V",                              (void *)com_media_ffmpeg_FFMpegPlayer_pause},

    {"isPlaying",           "()Z",                              (void *)com_media_ffmpeg_FFMpegPlayer_isPlaying},

    {"getCurrentPosition",  "()I",                              (void *)com_media_ffmpeg_FFMpegPlayer_getCurrentPosition},

    {"getDuration",         "()I",                              (void *)com_media_ffmpeg_FFMpegPlayer_getDuration},

    {"_release",            "()V",                              (void *)com_media_ffmpeg_FFMpegPlayer_release},

    {"_reset",              "()V",                              (void *)com_media_ffmpeg_FFMpegPlayer_reset},

    {"setAudioStreamType",  "(I)V",                             (void *)com_media_ffmpeg_FFMpegPlayer_setAudioStreamType},

    {"native_init",         "()V",                              (void *)com_media_ffmpeg_FFMpegPlayer_native_init},

    {"native_setup",        "(Ljava/lang/Object;)V",            (void *)com_media_ffmpeg_FFMpegPlayer_native_setup},

    {"native_finalize",     "()V",                              (void *)com_media_ffmpeg_FFMpegPlayer_native_finalize},

    {"native_suspend_resume", "(Z)I",                           (void *)com_media_ffmpeg_FFMpegPlayer_native_suspend_resume},

};