使用c语言生成一个可以预览所有格式为png图片的滑动列表
时间: 2023-07-15 22:12:05 浏览: 99
要实现这个功能,你需要掌握以下技术:
1. C语言编程基础
2. 图形库的使用,例如GTK+、SDL、OpenGL等
3. PNG图片文件的读取和解码,可以使用libpng库
下面是一个使用GTK+库实现的示例代码,可以生成一个滑动列表,可以预览指定目录下所有格式为PNG的图片。
```c
#include <gtk/gtk.h>
#include <stdlib.h>
#include <string.h>
#include <dirent.h>
#include <png.h>
// 定义图片信息结构体
typedef struct {
int width;
int height;
unsigned char* data;
} ImageInfo;
// 读取PNG图片文件
ImageInfo* read_png_file(char* filename) {
FILE* fp = fopen(filename, "rb");
if (!fp) {
return NULL;
}
png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr) {
fclose(fp);
return NULL;
}
png_infop info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr) {
png_destroy_read_struct(&png_ptr, NULL, NULL);
fclose(fp);
return NULL;
}
if (setjmp(png_jmpbuf(png_ptr))) {
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
fclose(fp);
return NULL;
}
png_init_io(png_ptr, fp);
png_read_info(png_ptr, info_ptr);
int width = png_get_image_width(png_ptr, info_ptr);
int height = png_get_image_height(png_ptr, info_ptr);
png_byte color_type = png_get_color_type(png_ptr, info_ptr);
png_byte bit_depth = png_get_bit_depth(png_ptr, info_ptr);
if (bit_depth == 16) {
png_set_strip_16(png_ptr);
}
if (color_type == PNG_COLOR_TYPE_PALETTE) {
png_set_palette_to_rgb(png_ptr);
}
if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
png_set_expand_gray_1_2_4_to_8(png_ptr);
}
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
png_set_tRNS_to_alpha(png_ptr);
}
if (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_PALETTE) {
png_set_filler(png_ptr, 0xFF, PNG_FILLER_AFTER);
}
if (color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
png_set_gray_to_rgb(png_ptr);
}
png_read_update_info(png_ptr, info_ptr);
png_bytep* row_pointers = (png_bytep*) malloc(sizeof(png_bytep) * height);
for (int i = 0; i < height; i++) {
row_pointers[i] = (png_byte*) malloc(png_get_rowbytes(png_ptr, info_ptr));
}
png_read_image(png_ptr, row_pointers);
ImageInfo* image = (ImageInfo*) malloc(sizeof(ImageInfo));
image->width = width;
image->height = height;
image->data = (unsigned char*) malloc(width * height * 4);
for (int y = 0; y < height; y++) {
png_bytep row = row_pointers[y];
for (int x = 0; x < width; x++) {
png_bytep px = &(row[x * 4]);
image->data[(y * width + x) * 4 + 0] = px[0];
image->data[(y * width + x) * 4 + 1] = px[1];
image->data[(y * width + x) * 4 + 2] = px[2];
image->data[(y * width + x) * 4 + 3] = px[3];
}
}
for (int i = 0; i < height; i++) {
free(row_pointers[i]);
}
free(row_pointers);
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
fclose(fp);
return image;
}
// 释放图片信息结构体内存
void free_image_info(ImageInfo* image) {
if (image) {
if (image->data) {
free(image->data);
}
free(image);
}
}
// 根据指定目录获取所有PNG图片文件名
void get_png_file_list(const char* dir_path, char** file_list, int* count) {
DIR* dir = opendir(dir_path);
if (!dir) {
return;
}
int i = 0;
struct dirent* ent;
while ((ent = readdir(dir)) != NULL) {
if (strstr(ent->d_name, ".png") != NULL || strstr(ent->d_name, ".PNG") != NULL) {
file_list[i] = strdup(ent->d_name);
i++;
}
}
*count = i;
closedir(dir);
}
int main(int argc, char** argv) {
GtkWidget* window;
GtkWidget* scrolled_window;
GtkWidget* box;
gtk_init(&argc, &argv);
window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
gtk_window_set_title(GTK_WINDOW(window), "PNG Image Viewer");
gtk_window_set_default_size(GTK_WINDOW(window), 640, 480);
gtk_container_set_border_width(GTK_CONTAINER(window), 10);
scrolled_window = gtk_scrolled_window_new(NULL, NULL);
gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(scrolled_window), GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC);
box = gtk_box_new(GTK_ORIENTATION_VERTICAL, 5);
gtk_container_add(GTK_CONTAINER(scrolled_window), box);
char* file_list[1024];
int file_count = 0;
get_png_file_list(".", file_list, &file_count);
for (int i = 0; i < file_count; i++) {
ImageInfo* image = read_png_file(file_list[i]);
if (image) {
GdkPixbuf* pixbuf = gdk_pixbuf_new_from_data(image->data, GDK_COLORSPACE_RGB, TRUE, 8, image->width, image->height, image->width * 4, NULL, NULL);
GtkWidget* image_widget = gtk_image_new_from_pixbuf(pixbuf);
gtk_widget_set_size_request(image_widget, 100, 100);
gtk_box_pack_start(GTK_BOX(box), image_widget, FALSE, FALSE, 0);
free_image_info(image);
g_object_unref(pixbuf);
}
free(file_list[i]);
}
gtk_container_add(GTK_CONTAINER(window), scrolled_window);
g_signal_connect(G_OBJECT(window), "destroy", G_CALLBACK(gtk_main_quit), NULL);
gtk_widget_show_all(window);
gtk_main();
return 0;
}
```
该示例代码中使用了libpng库读取PNG图片文件,并使用GTK+库生成了一个滑动列表。你可以根据需要修改代码,来实现你自己的需求。
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