c - GTK+ 2.0 C 奇怪的结构和 g_signal_connect_swapped

Question

我有以下声明:

typedef struct window_and_search_entry
{
    GtkWidget *window;
    GtkWidget *search_entry;
} WINDOW_AND_SEARCH_ENTRY;

and then in main:

GtkWidget *window;
GtkWidget *search_entry;

...

WINDOW_AND_SEARCH_ENTRY window_and_search_entry;
window_and_search_entry.window = window;
window_and_search_entry.search_entry = search_entry;

还有那两个:

g_signal_connect_swapped(G_OBJECT(search_entry), "activate", G_CALLBACK(analyse), (gpointer) &window_and_search_entry);

g_signal_connect_swapped(G_OBJECT(do_it_button), "clicked", G_CALLBACK(analyse), (gpointer) &window_and_search_entry); 

我想创建接受文本和窗口的函数，对其进行一些操作，如果发生错误，则使用其他接受窗口作为参数的函数将其打印出来

ELEMENT *analyse(GtkWidget *widget, gpointer user_data)
{
    //((WINDOW_AND_SEARCH_ENTRY *) user_data)->search_entry;
    GtkWidget *a = ((WINDOW_AND_SEARCH_ENTRY*)(user_data))->search_entry;
    const char *text = gtk_entry_get_text(GTK_ENTRY(a));
    g_print("%s\n", text);




    ELEMENT *heap[100];
    int index = 0;


    return heap[1];
} 

我尝试了很多变体，但在 entry_box 中输入内容后按回车或按钮后出现“段错误”。我想将文本打印到控制台。请帮助我，谢谢。

Answer 1

您的analyse 回调需要g_signal_connect，而不是g_signal_connect_swapped。也不需要转换指针:G_CALLBACK() 宏已经转换了整个函数，所以这就足够了:

ELEMENT *analyse(GtkWidget *widget, WINDOW_AND_SEARCH_ENTRY *data)

使用 g_signal_connect_swapped 它将是:

ELEMENT *analyse(WINDOW_AND_SEARCH_ENTRY *data, GtkWidget *widget);

这个交换版本只是对已有函数的 C 便利，例如你可以这样做:

g_signal_connect_swapped(G_OBJECT(search_entry), "activate",
                         G_CALLBACK(g_print), "Activate signal called");