GtkEntry操纵
GtkEntry操纵
提问于 2014-03-18 19:02:29
我正在尝试制作一个小程序，用于在GtkEntry字段之间对数据进行处理。为了做到这一点，我使用全局变量。但是使用g_print函数向我展示我得到的空数据的内容！我的路怎么了？
#include <gtk/gtk.h>
const gchar *entry0_text;
const gchar *entry1_text;
const gchar *entry2_text;
static void my_function (GtkWidget *widget, GtkWidget *entry)
{
g_print ("Entry0 contents: %s\n", gtk_entry_get_text (GTK_ENTRY (entry)));
g_print ("Entry1 contents: %s\n", *entry0_text);
g_print ("Entry2 contents: %s\n", *entry1_text);
}
static void
activate (GtkApplication *app,
gpointer user_data)
{
GtkWidget *window;
GtkWidget *grid;
GtkWidget *button;
GtkWidget *entry0;
GtkWidget *entry1;
GtkWidget *entry2;
window = gtk_application_window_new (app);
gtk_window_set_title (GTK_WINDOW (window), ":-)");
gtk_window_set_default_size (GTK_WINDOW (window), 300, 300);
gtk_container_set_border_width (GTK_CONTAINER (window), 20);
grid = gtk_grid_new ();
gtk_container_add (GTK_CONTAINER (window), GTK_WIDGET (grid));
entry0 = gtk_entry_new ();
gtk_grid_attach (GTK_GRID (grid), entry0, 0, 0, 1, 1);
entry0_text = gtk_entry_get_text (GTK_ENTRY (entry0));
entry1 = gtk_entry_new ();
gtk_grid_attach (GTK_GRID (grid), entry1, 1, 0, 1, 1);
entry1_text = gtk_entry_get_text (GTK_ENTRY (entry1));
entry2 = gtk_entry_new ();
gtk_grid_attach (GTK_GRID (grid), entry2, 0, 1, 1, 1);
entry2_text = gtk_entry_get_text (GTK_ENTRY (entry2));
button = gtk_button_new ();
gtk_grid_attach (GTK_GRID (grid), button, 1, 1, 1, 1);
g_signal_connect (button, "clicked", G_CALLBACK (my_function), entry0);
gtk_widget_show_all (window);
}
int
main (int argc, char **argv)
{
GtkApplication *app;
int status;
app = gtk_application_new ("org.gtk.example", G_APPLICATION_FLAGS_NONE);
g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
status = g_application_run (G_APPLICATION (app), argc, argv);
g_object_unref (app);
return status;
}我使用Debian /Linux并使用这样的脚本进行编译: gcc pkg-config --libs --cflags gtk+-3.0 -o $2 $1
谢谢!
回答 1
Stack Overflow用户
回答已采纳
发布于 2014-03-18 20:21:14
在程序启动期间检索entry0_text - entry2.text的值。但是由于还没有输入，所以它们包含空字符串。
您必须对回调函数my_function中的所有条目小部件使用my_function，而不是在activate函数中。
此外，您使用的第二和第三g_print错误；您应该使用
g_print ("Entry1 contents: %s\n", entry1_text);
g_print ("Entry2 contents: %s\n", entry2_text);请记住，程序启动后，entry1_text和entry2_text包含空字符串。但是使用*entry1_text和*entry2_text，您将不会接收空字符串，而是该字符串的第一个元素，即终止的'\0‘空字符，这就是为什么您收到这些g_prints的' null’。所以使用entry1_text而不是*entry1_text。
下面的代码工作正常；为了简单起见，我使用条目小部件和字符串作为全局变量。
#include <gtk/gtk.h>
#include <string.h>
GtkWidget *entry0;
GtkWidget *entry1;
GtkWidget *entry2;
const gchar *entry0_text;
const gchar *entry1_text;
const gchar *entry2_text;
static void my_function (void)
{
entry0_text = gtk_entry_get_text (GTK_ENTRY (entry0));
entry1_text = gtk_entry_get_text (GTK_ENTRY (entry1));
entry2_text = gtk_entry_get_text (GTK_ENTRY (entry2));
g_print ("Entry0 contents: %s\n", entry0_text);
g_print ("Entry1 contents: %s\n", entry1_text);
g_print ("Entry2 contents: %s\n", entry2_text);
}
static void
activate (GtkApplication *app,
gpointer user_data)
{
GtkWidget *window;
GtkWidget *grid;
GtkWidget *button;
window = gtk_application_window_new (app);
gtk_window_set_title (GTK_WINDOW (window), ":-)");
gtk_window_set_default_size (GTK_WINDOW (window), 300, 300);
gtk_container_set_border_width (GTK_CONTAINER (window), 20);
grid = gtk_grid_new ();
gtk_container_add (GTK_CONTAINER (window), GTK_WIDGET (grid));
entry0 = gtk_entry_new ();
gtk_grid_attach (GTK_GRID (grid), entry0, 0, 0, 1, 1);
entry1 = gtk_entry_new ();
gtk_grid_attach (GTK_GRID (grid), entry1, 1, 0, 1, 1);
entry2 = gtk_entry_new ();
gtk_grid_attach (GTK_GRID (grid), entry2, 0, 1, 1, 1);
button = gtk_button_new ();
gtk_grid_attach (GTK_GRID (grid), button, 1, 1, 1, 1);
g_signal_connect (button, "clicked", G_CALLBACK (my_function), NULL);
gtk_widget_show_all (window);
}
int
main (int argc, char **argv)
{
GtkApplication *app;
int status;
app = gtk_application_new ("org.gtk.example", G_APPLICATION_FLAGS_NONE);
g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
status = g_application_run (G_APPLICATION (app), argc, argv);
g_object_unref (app);
return status;
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/22488665
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