android - 即使包含，也无法创建 SDL_Window 给出 SDL_Main.h 错误

Question

我正在尝试使用 FFMPEG(Fetching,decode.etc) 播放网络流，并尝试使用 SDL 渲染它。

当我运行我的应用程序时，它会正常启动，但只要我调用 OpenFile()其中包含用于打开网络流并创建 SDL_Window 和 SDL_Renderer 的代码，但它在 SDL_CreateWindow() 上给了我一个错误说:
Window not created: [Application didn't initialize properly, did you include SDL_main.h in the file containing your main() function?].
即使我已包含 SDL_main.h .

#include <SDL.h>
#include <SDL_main.h>
..... //other header files

#define  LOGI(...)  __android_log_print(ANDROID_LOG_INFO,LOG_TAG,__VA_ARGS__)
#define  LOGE(...)  __android_log_print(ANDROID_LOG_ERROR,LOG_TAG,__VA_ARGS__)

SDL_Window *window;
SDL_Renderer *renderer;

int main(int argc, char *argv[])
{
    if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER))
    {
      LOGE("Could not initialize SDL - %s\n", SDL_GetError());
      exit(1);
    }
    return 0;
 }

 void Java_com_my_app_MainActivity_openFile(JNIEnv * env, jobject this, jstring url)
 {
    ......
    ...... //FFMPEG code

  //---------------------------SDL part -------------------------//

  window = SDL_CreateWindow("Window", SDL_WINDOWPOS_UNDEFINED,
           SDL_WINDOWPOS_UNDEFINED, 0, 0,
           SDL_WINDOW_SHOWN | SDL_WINDOW_FULLSCREEN);

   if(window == NULL)
   {
       LOGE("Window not created: [%s]", SDL_GetError());
       return;
   }
   LOGE("Window created");

  renderer = SDL_CreateRenderer(window,-1,SDL_RENDERER_ACCELERATED | SDL_RENDERER_TARGETTEXTURE);
   if(renderer == NULL)
   {
       LOGE("renderer not created: [%s]", SDL_GetError());
       return;
   }
   LOGE("Rendering Created...");
}

这是我尝试过的另一个项目的代码(遵循 this 教程)，我的 MainActivity 中没有我工作正常

   #include <stdlib.h>
   #include <stdio.h>
   #include <time.h>

   #include "SDL.h"

 typedef struct Sprite
 {
   SDL_Texture* texture;
   Uint16 w;
   Uint16 h;
 } Sprite;

Sprite LoadSprite(const char* file, SDL_Renderer* renderer)
{
    Sprite result;
    result.texture = NULL;
    result.w = 0;
    result.h = 0;

    SDL_Surface* temp;

    /* Load the sprite image */
    temp = SDL_LoadBMP(file);
    if (temp == NULL)
    {
        fprintf(stderr, "Couldn't load %s: %s\n", file, SDL_GetError());
        return result;
    }
    result.w = temp->w;
    result.h = temp->h;

    /* Create texture from the image */
    result.texture = SDL_CreateTextureFromSurface(renderer, temp);
    if (!result.texture) {
        fprintf(stderr, "Couldn't create texture: %s\n", SDL_GetError());
        SDL_FreeSurface(temp);
        return result;
    }
    SDL_FreeSurface(temp);

    return result;
}

void draw(SDL_Window* window, SDL_Renderer* renderer, const Sprite sprite)
{
    int w, h;
    SDL_GetWindowSize(window, &w, &h);
    SDL_Rect destRect = {w/2 - sprite.w/2, h/2 - sprite.h/2, sprite.w, sprite.h};
    /* Blit the sprite onto the screen */
    SDL_RenderCopy(renderer, sprite.texture, NULL, &destRect);
}

int main(int argc, char *argv[])
{
    if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER))
    {
         fprintf(stderr, "Could not initialize SDL - %s\n", SDL_GetError());
         exit(1);
    }

    SDL_Window *window;
    SDL_Renderer *renderer;

    if(SDL_CreateWindowAndRenderer(0, 0, 0, &window, &renderer) < 0)
        exit(2);

    Sprite sprite = LoadSprite("image.bmp", renderer);
    if(sprite.texture == NULL)
        exit(2);

    /* Main render loop */
    Uint8 done = 0;
    SDL_Event event;
    while(!done)
    {
        /* Check for events */
        while(SDL_PollEvent(&event))
        {
            if(event.type == SDL_QUIT || event.type == SDL_KEYDOWN )//|| event.type == SDL_FINGERDOWN)
            {
                done = 1;
            }
        }


    /* Draw a gray background */
    SDL_SetRenderDrawColor(renderer, 0xA0, 0xA0, 0xA0, 0xFF);
    SDL_RenderClear(renderer);

    draw(window, renderer, sprite);

    /* Update the screen! */
    SDL_RenderPresent(renderer);

    SDL_Delay(10);
}

exit(0);

}

注意:我从这个正常工作的项目中创建了第一个项目(给出错误的项目)

我曾尝试使用#undef main 删除 SDL_main.h'，但都不起作用。现在它开始给我一个错误说 'java.lang.UnsatisfiedLinkError: Cannot load library: soinfo_relocate(linker.cpp:975): cannot locate symbol "SDL_main" referenced by "libmain.so"...
我的安卓.mk

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
LOCAL_MODULE := ffmpeg
LOCAL_SRC_FILES := $(TARGET_ARCH_ABI)/libffmpeg.so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/$(TARGET_ARCH_ABI)/include
include $(PREBUILT_SHARED_LIBRARY)


include $(CLEAR_VARS)
SDL_PATH := ../SDL
MY_FILES_PATH := ../src
LOCAL_MODULE    := main
# Add your application source files here...
LOCAL_SRC_FILES := $(SDL_PATH)/src/main/android/SDL_android_main.c \
                   $(patsubst $(LOCAL_PATH)/%, %, $(wildcard $(LOCAL_PATH)/src/*.c)) 

LOCAL_C_INCLUDES := $(LOCAL_PATH)/$(SDL_PATH)/include
LOCAL_LDLIBS := -L$(SYSROOT)/usr/lib -ljnigraphics -lGLESv1_CM -lGLESv2 -llog -lz -lm 
LOCAL_ALLOW_UNDEFINED_SYMBOLS := true
LOCAL_SHARED_LIBRARIES := SDL2
LOCAL_SHARED_LIBRARIES += ffmpeg 
include $(BUILD_SHARED_LIBRARY)

Answer 1

无需包含 SDL_main.h，因为它包含在 SDL.h 中，我认为问题出在您的 main 函数中。

我试过你的代码，在 Visual Studio 中编译得很好。

创建一个新项目并按照以下步骤操作 http://www.willusher.io/sdl2%20tutorials/2013/08/15/lesson-0-setting-up-sdl/