输出文字怎么都不起效。。。运行4个succeed但就是打印不出来
#include <SDL2/SDL.h>
#include <iostream>
#include <SDL2/SDL_ttf.h>
using namespace std;
SDL_Window*win=SDL_CreateWindow("test",800,80,600,600,SDL_WINDOW_SHOWN);
SDL_Renderer*ren=SDL_CreateRenderer(win,-1,SDL_RENDERER_ACCELERATED|SDL_RENDERER_PRESENTVSYNC);
int main(int argc,char**argv)
{
if(ren==NULL)
cout<<"fail"<<endl;
else
cout<<"succeed"<<endl;
TTF_Init() ;
SDL_Color color = { 255, 255, 255 };
SDL_Rect pos;
pos.x=300,pos.y=300;
TTF_Font *font =TTF_OpenFont("font_a.ttf",36);
if(font==NULL)
cout<<"fail"<<endl;
else
cout<<"succeed"<<endl;
SDL_Surface *surf = TTF_RenderText_Solid(font,"hello world",color);
if(surf==NULL)
cout<<"fail"<<endl;
else
cout<<"succeed"<<endl;
SDL_Texture *texture = SDL_CreateTextureFromSurface(ren, surf);
if(texture==NULL)
cout<<"fail"<<endl;
else
cout<<"succeed"<<endl;
SDL_RenderCopy(ren ,texture,NULL,&pos);
SDL_RenderPresent(ren);
SDL_Delay(2000);
SDL_FreeSurface(surf);
TTF_CloseFont(font);
return 0;
}
@twtfcu3 我已经折腾了一天了。。。仍然是第一次打开花屏，以后运行黑屏

@木影随风

SDL_RenderClear(ren);
SDL_RenderCopy(ren ,texture,NULL,NULL);
SDL_RenderPresent(ren);
SDL_Delay(2000);

#include <SDL2/SDL.h>
#include <iostream>
#include <SDL2/SDL_ttf.h>
using namespace std;
int main(int argc,char**argv)
{
SDL_Window*win=SDL_CreateWindow("test",800,80,600,600,SDL_WINDOW_SHOWN);
SDL_Renderer*ren=SDL_CreateRenderer(win,-1,SDL_RENDERER_ACCELERATED|SDL_RENDERER_PRESENTVSYNC);
if(ren==NULL)
cout<<"fail"<<endl;
else
cout<<"succeed"<<endl;
TTF_Init() ;
SDL_Color color = { 255, 255, 255 };
SDL_Rect pos;
pos.x=300,pos.y=300;
TTF_Font *font =TTF_OpenFont("aa.ttf",36);
if(font==NULL)
cout<<"fail"<<endl;
else
cout<<"succeed"<<endl;
SDL_Surface *surf = TTF_RenderText_Solid(font,"hello world",color);
if(surf==NULL)
cout<<"fail"<<endl;
else
cout<<"succeed"<<endl;
SDL_Texture *texture = SDL_CreateTextureFromSurface(ren, surf);
if(texture==NULL)
cout<<"fail"<<endl;
else
cout<<"succeed"<<endl;
SDL_RenderClear(ren);
SDL_RenderCopy(ren ,texture,NULL,NULL);
SDL_RenderPresent(ren);
SDL_Delay(2000);
SDL_FreeSurface(surf);
TTF_CloseFont(font);
return 0;
}

还是不行。。。
会不会是显卡的原因呢？我会出现花屏。

建议你把
SDL_Window*win=SDL_CreateWindow("test",800,80,600,600,SDL_WINDOW_SHOWN);
SDL_Renderer*ren=SDL_CreateRenderer(win,-1,SDL_RENDERER_ACCELERATED|SDL_RENDERER_PRESENTVSYNC);
放到main函数中。
main函数的所有程序执行的开始，是入口。
如果上面的两句不放在main里，就是没有执行过，也就是说win和ren没有初始化，是空的。如此，你说它会显示窗口吗？
我帮你修改了下，运行结果如下：
完整代码：
int main(int argc, char**argv)
{
SDL_Init(SDL_INIT_EVERYTHING);//你连SDL都没初始化
TTF_Init();
SDL_Window*win = SDL_CreateWindow("test", 800, 80, 600, 600, SDL_WINDOW_SHOWN);
SDL_Renderer*ren = SDL_CreateRenderer(win, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
if (ren == NULL || win==NULL)//两个都测试吧
cout << "无法创建窗口或渲染器" << endl;
else
cout << "成功创建窗口或渲染器" << endl;
SDL_Color color = { 255, 0, 0 };//红色
SDL_Rect pos;
pos.x = 100, pos.y = 100,pos.w=400,pos.h=100;//四个成员都要设定，不能只设置部分，出错的部分在此
TTF_Font *font = TTF_OpenFont("C:\\Windows\\Fonts\\msyh.ttc", 36);
//注意字体路径的完整性和书写
if (font == NULL)
cout << "字体打开失败" << endl;
else
cout << "字体打开成功" << endl;
SDL_Surface *surf = TTF_RenderText_Solid(font, "hello world", color);
if (surf == NULL)
cout << "fail" << endl;
else
cout << "succeed" << endl;
SDL_Texture *texture = SDL_CreateTextureFromSurface(ren, surf);
if (texture == NULL)
cout << "fail" << endl;
else
cout << "succeed" << endl;
SDL_RenderCopy(ren, texture, NULL, &pos);
SDL_RenderPresent(ren);
SDL_Delay(2000);
getchar();//控制台暂停
SDL_DestroyTexture(texture);//纹理也要销毁
SDL_FreeSurface(surf);
TTF_CloseFont(font);
return 0;
}