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我不知道出了什么问题。当我尝试编写 PNG 时，出现错误：“写入标头时出错”。

我需要包含其他内容吗？我从这里获取了 .lib/.h 文件：http ://www.eden.net.nz/7/20071024/

编辑：我终于设法完成了这项工作。

解决方案：

#pragma comment(lib, "zlib_s.lib") // must be before libpng!
#pragma comment(lib, "libpng_s.lib") // must be after zlib!

很奇怪吧？

这是工作代码，它是一个稍微修改过的版本：http://zarb.org/~gc/html/libpng.html
未来注意：这必须编译为 C 代码！

#pragma comment(lib, "zlib_s.lib") // must be before libpng!
#pragma comment(lib, "libpng_s.lib") // must be after zlib!

#define PNG_DEBUG 0
#include "png.h"

int x, y;

int width, height;
png_byte color_type;
png_byte bit_depth;

png_structp png_ptr;
png_infop info_ptr;
int number_of_passes;
png_bytep *row_pointers;


char *save_png(char *savefile, void *data_in, int w, int h, int BPP){
    unsigned char *data = (unsigned char *)*data_in;
    int p = 0;
    FILE *fp;

    width = w;
    height = h;
    color_type = 2;
    bit_depth = 8;

    // create file 
    fp = fopen(savefile, "wb");
    if(!fp) return "[write_png_file] File %s could not be opened for writing";

    // initialize stuff 
    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
    if(!png_ptr) return "[write_png_file] png_create_write_struct failed";

    info_ptr = png_create_info_struct(png_ptr);
    if(!info_ptr) return "[write_png_file] png_create_info_struct failed";
    if(setjmp(png_jmpbuf(png_ptr))) return "[write_png_file] Error during init_io";

    png_init_io(png_ptr, fp);
    // write header 
    if(setjmp(png_jmpbuf(png_ptr))) return "[write_png_file] Error during writing header";

    png_set_IHDR(
        png_ptr, info_ptr, width, height,
        bit_depth, color_type, PNG_INTERLACE_NONE,
        PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE
    );

    png_write_info(png_ptr, info_ptr);

    row_pointers = (png_bytep*)malloc(sizeof(png_bytep) * height);
    for(y = 0; y < height; y++){
        row_pointers[y] = (png_byte*)malloc(width*BPP);//png_get_rowbytes(png_ptr,info_ptr));
        for(x = 0; x < width; x++){
            row_pointers[y][x*BPP+0] = data[p++];
            row_pointers[y][x*BPP+1] = data[p++];
            row_pointers[y][x*BPP+2] = data[p++];
        }
    }
    // write bytes 
    if(setjmp(png_jmpbuf(png_ptr))) return "[write_png_file] Error during writing bytes";

    png_write_image(png_ptr, row_pointers);

    // end write 
    if(setjmp(png_jmpbuf(png_ptr))) return "[write_png_file] Error during end of write";

    png_write_end(png_ptr, NULL);

    // cleanup heap allocation 
    for(y = 0; y < height; y++){
        free(row_pointers[y]);
    }
    free(row_pointers);

    fclose(fp);

    return "0";
}
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1 回答 1

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问题出在图书馆的顺序上：

#pragma comment(lib, "zlib_s.lib") // must be before libpng!
#pragma comment(lib, "libpng_s.lib") // must be after zlib!

奇怪，但这解决了问题！

于 2012-09-20T20:25:44.473 回答