Question

所以我正在使用SDL2和C ++创建一个2D Pong游戏（我对此完全陌生！）一切顺利，直到我遇到这个错误：

Exception thrown at 0x71002A85 (SDL2_ttf.dll) in 2D Game.exe: 0xC0000005: Access violation reading location 0x00000000.

代码断开：

SDL_Surface * surf = TTF_RenderText_Blended（font，message.c_str（），color）;

#include "utilities.h"

#include <SDL.h>
#include <SDL_ttf.h>

void renderTexture(SDL_Texture* tex,
        SDL_Renderer* ren, SDL_Rect dst, SDL_Rect *clip) {
    SDL_RenderCopy(ren, tex, clip, &dst);
}

void renderTexture(SDL_Texture* tex,
        SDL_Renderer* ren, int x, int y, SDL_Rect* clip) {
    SDL_Rect dst;
    dst.x = x;
    dst.y = y;
    if (clip != nullptr) {
        dst.w = clip->w;
        dst.h = clip->h;
    } else {
        SDL_QueryTexture(tex, nullptr, nullptr, &dst.w, &dst.h);
    }

    renderTexture(tex, ren, dst, clip);
}

SDL_Texture* renderText(const std::string &message,
    const std::string &fontFile, SDL_Color color,
    int fontSize, SDL_Renderer* renderer) {

    TTF_Font* font = TTF_OpenFont(fontFile.c_str(), fontSize);

SDL_Surface* surf = TTF_RenderText_Blended(font, message.c_str(), color);

SDL_Texture* texture = SDL_CreateTextureFromSurface(renderer, surf);

SDL_FreeSurface(surf);
TTF_CloseFont(font);

return texture;

}

Answer 1

您应该检查之前返回的PCL对象为null。如果font无法打开给定的字体文件，则TTF_OpenFont很可能返回null。

TTF_Font* font = TTF_OpenFont(fontFile.c_str(), fontSize);

if(!font) {
   ... //some action here, perhaps throw exception
}
SDL_Surface* surf = TTF_RenderText_Blended(font, message.c_str(), color);

异常抛出0x71002A85（SDL2_ttf.dll）

1 个答案: