GtkLabel

到目前為止一直在用的GtkLabel，其實可以設定更多的樣式，例如簡單的標記（markup）、換行、對齊、自動換行等。

要設定標記可以使用gtk_label_set_markup()函式，要設定換行，可以使用'\n'來斷行，或是使用 gtk_label_set_line_wrap()設定依容器寬度自動換行，要設定對齊可以使用gtk_label_set_justify()，預設是置中對齊，可以設定的值包括了：

GTK_JUSTIFY_CENTER：置中對齊(預設)
GTK_JUSTIFY_LEFT：靠左對齊
GTK_JUSTIFY_RIGHT：靠右對齊
GTK_JUSTIFY_FILL：左右對齊

以下使用一個程式實例，來看看設定過程與執行後的效果：

gtk_label_demo.c

#include <gtk/gtk.h>

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

    gtk_init(&argc, &argv);

    window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    gtk_window_set_title(GTK_WINDOW(window), "GtkLabel");
    gtk_window_set_default_size(GTK_WINDOW(window), 400, 400);

    vbox = gtk_vbox_new(FALSE, 5);

    frame = gtk_frame_new("簡單標記");
    label = gtk_label_new(NULL);
    gtk_label_set_markup(GTK_LABEL(label), 
       "<span foreground='blue' size='x-large'>良葛格學習筆記</span>");
    gtk_container_add(GTK_CONTAINER(frame), label);
    gtk_box_pack_start(GTK_BOX(vbox), frame, FALSE, FALSE, 0);

    frame = gtk_frame_new("多行");
    label = gtk_label_new("良葛格學習筆記\ncaterpillar.onlyfun.net\n" \
			   "Gossip@Openhome");
    gtk_container_add(GTK_CONTAINER(frame), label);
    gtk_box_pack_start(GTK_BOX(vbox), frame, FALSE, FALSE, 0);

    frame = gtk_frame_new("自動換行");
    label = gtk_label_new("You might think you know but actually you don't. " \
                          "You might think you know but actually you don't. " \
                          "You might think you know but actually you don't. " \
                          "You might think you know but actually you don't.");
    gtk_label_set_line_wrap(GTK_LABEL(label), TRUE);
    gtk_container_add(GTK_CONTAINER(frame), label);
    gtk_box_pack_start(GTK_BOX(vbox), frame, FALSE, FALSE, 0);

    frame = gtk_frame_new("靠右對齊");
    label = gtk_label_new("良葛格學習筆記\ncaterpillar.onlyfun.net\n" \
                           "Gossip@Openhome");
    gtk_label_set_justify(GTK_LABEL(label), GTK_JUSTIFY_RIGHT);
    gtk_container_add(GTK_CONTAINER(frame), label);
    gtk_box_pack_start(GTK_BOX(vbox), frame, FALSE, FALSE, 0);
    
    frame = gtk_frame_new("自動換行、左右對齊");
    label = gtk_label_new("You might think you know but actually you don't. " \
                          "You might think you know but actually you don't. " \
                          "You might think you know but actually you don't. " \
                          "You might think you know but actually you don't.");
    gtk_label_set_line_wrap(GTK_LABEL(label), TRUE);
    gtk_label_set_justify(GTK_LABEL(label), GTK_JUSTIFY_FILL);
    gtk_container_add(GTK_CONTAINER(frame), label);
    gtk_box_pack_start(GTK_BOX(vbox), frame, FALSE, FALSE, 0);

    gtk_container_add(GTK_CONTAINER(window), vbox);

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

    gtk_main();

    return 0;
}

執行結果如下所示：