如何設置佔位符文本在GtkEntry中

Question

我試過了這個例子：

#include <stdio.h> 
#include <stdlib.h> 
#include <gtk/gtk.h> 

GdkPixbuf *create_pixbuf(const gchar * filename) {  
    GdkPixbuf *pixbuf; 
    GError *error = NULL; 
    pixbuf = gdk_pixbuf_new_from_file(filename, &error); 

    if(!pixbuf) {  
     fprintf(stderr, "%s\n", error->message); g_error_free(error);    
    } 

    return pixbuf; 
} 

void implement() {  
    printf("HI"); 
}  

int main(int argc, char *argv[]) {  
    GtkWidget *window; 
    GtkWidget *frame; 
    GtkWidget *label; 
    GtkWidget *text;  

    gtk_init(&argc, &argv); 
    window = gtk_window_new(GTK_WINDOW_TOPLEVEL); 
    gtk_window_set_title(GTK_WINDOW(window), "New Message"); 
    gtk_window_set_default_size(GTK_WINDOW(window), 310, 390); 
    gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER); 
    gtk_window_set_icon(GTK_WINDOW(window), create_pixbuf("web.png")); 

    frame = gtk_fixed_new(); 
    gtk_container_add(GTK_CONTAINER(window), frame);   

    text = gtk_entry_new(); 
    gtk_entry_set_max_length (GTK_ENTRY (text), 0); 
    gtk_entry_set_width_chars (GTK_ENTRY (text), 37); 
    gtk_entry_set_placeholder_text(GTK_ENTRY (text), "Send a message"); 
    gtk_fixed_put(GTK_FIXED(frame), text, 2, 360);  

    gtk_widget_show_all(window);   

    g_signal_connect(window, "destroy", G_CALLBACK (gtk_main_quit), NULL); 

    gtk_main(); 

    return 0;  
} 

，但得到的錯誤：undefined reference to gtk_entry_set_placeholder_text'`

Answer 1

確保您的GTK +的版本是3.2或更高版本，因爲這是在特定的功能加入。