c - 设置 GTK+ 条目或标签的文本不起作用

Question

我只是想在文本输入小部件内按 Enter 时更改从文本输入小部件获取的标签内的文本。我使用 Glade 来设计这个简单的界面，在窗口中只包含这两个小部件。然后使用glib-compile-resources test.xml转换为GIO资源并加载到程序中。

但标签没有改变。知道我做错了什么吗？编译器不会给出任何警告。我还可以打印我从 Glade 设置的标签内容。

测试.c

#include <gtk/gtk.h>

static void on_entry_activate(GtkWidget *entry, gpointer data) {
    const gchar *text = gtk_entry_get_text(GTK_ENTRY(entry));
    GtkBuilder *app_builder = gtk_builder_new_from_resource(
                              "/org/samik/test/test.glade");
    GObject *label = gtk_builder_get_object(app_builder, "label1");
    g_print("%s\n", gtk_label_get_text(GTK_LABEL(label)));
    gtk_label_set_text(GTK_LABEL(label), text);
}
static void on_app_activate(GApplication *app, gpointer data) {
    GError *res_load_err = NULL;
    GResource *app_res = g_resource_load("test.gresource", &res_load_err);
    g_resources_register(app_res);
    GtkBuilder *app_builder = gtk_builder_new_from_resource(
                              "/org/samik/test/test.glade");
    GObject *entry = gtk_builder_get_object(app_builder, "entry1");
    GObject *main_window = gtk_builder_get_object(app_builder, "window1");
    g_signal_connect(GTK_WIDGET(entry), "activate", 
        G_CALLBACK(on_entry_activate), NULL);
    gtk_window_set_application(GTK_WINDOW(main_window), GTK_APPLICATION(app));
    gtk_widget_show_all(GTK_WIDGET(main_window));
}
int main(int argc, char *argv[]) {
    int status;

    GtkApplication *app = gtk_application_new("org.samik.draw", 
                            G_APPLICATION_FLAGS_NONE);
    g_signal_connect(app, "activate", G_CALLBACK(on_app_activate), NULL);
    status = g_application_run(G_APPLICATION(app), argc, argv);

    g_object_unref(app);

    return status;
}

测试.glade

<?xml version="1.0" encoding="UTF-8"?>
<!-- Generated with glade 3.16.1 -->
<interface>
  <requires lib="gtk+" version="3.10"/>
  <object class="GtkWindow" id="window1">
    <property name="can_focus">False</property>
    <property name="title" translatable="yes">test</property>
    <child>
      <object class="GtkFixed" id="fixed1">
        <property name="visible">True</property>
        <property name="can_focus">False</property>
        <child>
         <!-- take whatever user types in this text-entry -->
          <object class="GtkEntry" id="entry1">
            <property name="width_request">100</property>
            <property name="height_request">80</property>
            <property name="visible">True</property>
            <property name="can_focus">True</property>
          </object>
          <packing>
            <property name="x">197</property>
            <property name="y">119</property>
          </packing>
        </child>
        <child>
          <!-- and put it here -->
          <object class="GtkLabel" id="label1">
            <property name="width_request">100</property>
            <property name="height_request">80</property>
            <property name="visible">True</property>
            <property name="can_focus">False</property>
            <property name="label" translatable="yes">label</property>
          </object>
          <packing>
            <property name="x">53</property>
            <property name="y">56</property>
          </packing>
        </child>
      </object>
    </child>
  </object>
</interface>

test.xml

<?xml version="1.0" encoding="UTF-8"?>
<gresources>
    <gresource prefix="/org/samik/test">
        <file compressed="true">test.glade</file>
    </gresource>
</gresources>

Answer 1

当您调用 gtk_builder_new_from_resource() 两次时，您实际上是在创建两个窗口(但只显示一个)。修改标签的调用是正确的，但它修改了不可见窗口中的标签。

在初始化时仅加载资源一次，并为回调函数提供指向实际小部件的指针。通常，您会创建一个结构体，其中包含指向稍后需要的所有小部件的指针，然后将指向该结构体的指针作为用户数据传递给 on_entry_activate() 等回调函数。