我想在gtk + cairo繪圖區域繪製一些線條(實際上是一個正弦波),但我無法想出一個辦法來做到這一點。 因此,我的代碼首先定義了繪圖區域,該區域具有回調到繪圖區域本身的白色背景的函數...此時,我想在每次START按鈕之後開始繪製一段正弦波被按下(該按鈕有一個回調繪圖功能).... 所以首先..有可能做到這一點??我錯過了什麼? 謝謝。GTK +如何繪製繪圖區域
#include <cairo.h>
#include <gtk/gtk.h>
int x = 0;
int x_old = 0;
float value = 0;
float value_old = 0;
GtkWidget *button = NULL;
GtkWidget *window = NULL;
GtkWidget *area = NULL;
GtkWidget *table = NULL;
static gboolean load_interface(GtkWidget *widget)
{
cairo_t *cr;
cr = gdk_cairo_create(area->window);
cairo_set_source_rgb(cr, 1, 1, 1);
cairo_rectangle(cr, 0, 0, 900, 400);
cairo_fill(cr);
}
void draw(GtkWidget *widget)
{
cairo_t *cr;
cr = gdk_cairo_create(widget->window);
x_old = x;
x = x + 15;
value_old = value;
value = value + 0.25;
cairo_set_source_rgb(cr, 0, 0, 0);
cairo_set_line_width (cr, 1);
cairo_move_to(cr, x_old, 100 + (sin(value_old))*50);
cairo_line_to(cr, x, 100 + (sin(value))*50);
cairo_stroke(cr);
}
int main (int argc, char *argv[])
{
g_log_set_handler ("Gtk", G_LOG_LEVEL_WARNING, (GLogFunc) gtk_false, NULL);
gtk_init (&argc, &argv);
g_log_set_handler ("Gtk", G_LOG_LEVEL_WARNING, g_log_default_handler, NULL);
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
gtk_container_set_border_width (GTK_CONTAINER (window), 3);
gtk_window_set_title (GTK_WINDOW (window), "Draw");
gtk_window_set_position (GTK_WINDOW (window), GTK_WIN_POS_CENTER);
gtk_widget_realize (window);
g_signal_connect (window, "destroy", gtk_main_quit, NULL);
table = gtk_table_new (10, 10, TRUE);
gtk_table_set_col_spacings(GTK_TABLE(table),10);
gtk_table_set_row_spacings(GTK_TABLE(table),5);
gtk_container_add (GTK_CONTAINER (window), table);
area = gtk_drawing_area_new();
gtk_signal_connect (GTK_OBJECT(area), "event", G_CALLBACK (load_interface), (gpointer)area);
gtk_table_attach_defaults (GTK_TABLE(table), area, 1, 10, 0, 10);
button = gtk_button_new_from_stock ("START");
g_signal_connect (G_OBJECT (button), "clicked", G_CALLBACK (draw), (gpointer) window);
gtk_table_attach_defaults (GTK_TABLE(table), button, 0, 1, 0, 1);
gtk_widget_show_all (window);
gtk_main();
return 0;
}
您使用的是GTK2還是GTK3?看起來它是GTK2,但我不確定。 – liberforce
是的,我在Windows上使用GTK2 ... – STiLLeN